Applied Water Science (v.7, #7)

Centralized wastewater management system is the modern day waste management practice, but the high cost and stringent requirements for the construction and operation have made it less attractive in the under-resourced regions of the world. Considering these challenges, the use of decentralized wastewater management system, on-site treatment system, as an appropriate technology for domestic wastewater treatment is hereby advocated. Adopting this technology helps save money, protects home owners’ investment, promotes better watershed management, offers an appropriate solution for low-density communities, provides suitable alternatives for varying site conditions and furnishes effective solutions for ecologically sensitive areas. In the light of this, an overview of the on-site treatment scheme, at the laboratory scale, pilot study stage, and field trials was conducted to highlight the operational principles’ strength and shortcomings of the scheme. The operational requirements for the establishing and operation of the scheme and best management practice to enhance the performance and sustenance were proffered.
Keywords: Appropriate technology; Domestic wastewater; On-site treatment; Percolator; Water pollution

Malachite green “a cationic dye” and its removal from aqueous solution by adsorption by Nirav P. Raval; Prapti U. Shah; Nisha K. Shah (3407-3445).
Adsorption can be efficiently employed for the removal of various toxic dyes from water and wastewater. In this article, the authors reviewed variety of adsorbents used by various researchers for the removal of malachite green (MG) dye from an aqueous environment. The main motto of this review article was to assemble the scattered available information of adsorbents used for the removal of MG to enlighten their wide potential. In addition to this, various optimal experimental conditions (solution pH, equilibrium contact time, amount of adsorbent and temperature) as well as adsorption isotherms, kinetics and thermodynamics data of different adsorbents towards MG were also analyzed and tabulated. Finally, it was concluded that the agricultural solid wastes and biosorbents such as biopolymers and biomass adsorbents have demonstrated outstanding adsorption capabilities for removal of MG dye.
Keywords: Malachite green; Wastewater; Biosorbents; Biopolymers; Nanomaterials

The present study focused on assessing the groundwater quality of the shallow aquifer in the northeastern Wasit Governorate, Iraq. The physicochemical parameters, including major cation and anion compositions, pH, total dissolved solid and electrical conductivity, were used to assess the suitability of groundwater quality for drinking purpose by comparing with the WHO and Iraqi standards. Total dissolved solid (TDS), sodium adsorption ratio, residual sodium bicarbonate, permeability index and magnesium ratio were used for irrigation suitability assessment. For this purpose, 98 samples were collected from the scattered shallow wells in the study area. Results indicated that the spatial distribution of TDS, EC values and major ions in these groundwater samples considerably differ from one site to another mainly due to the lithological variations of the area. The results are correlated with standards classifications to deduce the hydrogeo-chemical phenomena. The dominant factors in controlling the groundwater hydrogeochemistry are evaporation and weathering in the study area. Geochemical modelling approach was used to calculate the saturation state of some selected minerals, i.e., explaining the dissolution and precipitation reactions occurring in the groundwater. The studied groundwater samples were found to be oversaturated with carbonate minerals and undersaturated with evaporates minerals. A comparison of groundwater quality in relation to drinking water standards showed that most of the groundwater samples were unsuitable for drinking purposes. On the other hand, most groundwater is unsuitable for irrigation purposes based on sodium and salinity hazards. However, soil type as well as proper selection of plants should be taken into consideration.
Keywords: Groundwater quality; Wasit; Hydrogeochemistry; Saturation index; Groundwater suitability; Iraq

Comparative study of natural and modified biomass of Sargassum sp. for removal of Cd2+ and Zn2+ from wastewater by Zahid Mahmood; Samreen Zahra; Muhammad Iqbal; Muhammad Aamir Raza; Saqib Nasir (3469-3481).
Natural as well as acid modified dead biomass of brown marine alga Sargassum sp. was employed for the elimination of cadmium and zinc ions from synthetic wastewater; batch mode experiments were carried out to optimize various factors like adsorbent dosage, contact time, pH, agitation speed and primary metal ions concentration at room temperature (298.15 K) for both types of adsorbents i.e. natural and acid treated. Application of Langmuir and Freundlich isotherms suggested that the modified biomass adsorbed better as compared to the natural one; though sorption on the natural biomass was a physical process while that on the modified one was a physico-chemical process and thus was relatively difficult. The quantity of cadmium ions adsorbed was greater than that of zinc ions. Adsorption equilibrium for the metal ions sorption on treated Sargassum sp. biomass was established within 60 min for both cadmium and zinc ions with 95.3 and 90.1% removal efficiencies, respectively, but it was greatly influenced by the pH of the solution. The optimal conditions in the batch experiments were as follows: cadmium ions were removed effectively using 0.5 g of adsorbent and 5 mg/L initial metal ions concentration at pH 4 and 150 rpm agitation speed whereas the best results for zinc ions were obtained with 1 g of adsorbent and 5 mg/L initial metal ions concentration at pH 3 and 200 rpm agitation speed. The experimental data fitted well to the pseudo first order model as the values of metal uptake capacities were in good agreement with the experimental values. Thermodynamic studies show that the process is spontaneous and endothermic in nature. Desorption and regeneration studies reveal that recovery of biosorbent is low.
Keywords: Elimination; Wastewater; Batch mode experiments; Modified biomass; Sorption

The present study attempted to analyze the biosorption behavior of novel biosorbent, Araucaria heterophylla (green plant) biomass, to remove Cd+2 from solutions against various parameters, i.e., initial metal ion concentration, pH, temperature, sorbent dosage and biomass particle size. The maximum biosorption was found to be 90.02% at pH 5.5 and biosorption capacity (q e) of Cd+2 is 9.2506 mg g−1. The Langmuir and Freundlich equilibrium adsorption isotherms were studied and it was observed that Freundlich model is the best fit than the Langmuir model with correlation co-efficient of 0.999. Kinetic studies indicated that the biosorption process of Cd+2 well followed the pseudo-second-order model with R 2 0.999. Thermodynamic studies observed that the process is exothermic (ΔH ° negative). Free energy change (ΔG °) with negative sign reflected the feasibility and spontaneous nature of the process. The chemical functional –OH groups, CH2 stretching vibrations, C=O carbonyl group of alcohol, C=O carbonyl group of amide, P=O stretching vibrations and –CH groups were involved in the biosorption process. The XRD pattern of the A. heterophylla was found to be mostly amorphous in nature. The SEM studies showed Cd+2 biosorption on selective grains of the biosorbent. It was concluded that A. heterophylla leaf powder can be used as an effective, low-cost, and environmentally friendly biosorbent for the removal of Cd+2 from aqueous solution.
Keywords: Biosorption; Araucaria heterophylla ; Kinetics; Cadmium(II); FTIR; SEM

Distribution and degradation of organic matter with different molecular weight in an A2/O treatment system by Xiaoling Jin; Zhongqing Zhao; Zhe Qin; Da Lu; Shu-xuan Liang (3497-3502).
Organic matter (OM) fractions and their removal potentials in various stages of anaerobic–anoxic–oxic (A2/O) process were identified and evaluated. Molecular weight (MW) distribution of organic matter by continuous filtration method was used to characterize OM in influent and treated effluent. The results showed the MW of each reaction pool distributed in a U shape and ranged with particle size >0.45 μm and molecular weight <1 k accounted for a high proportion. These results suggested effluent organic matter <1 k of an anoxic pool, anaerobic pool, and an aerobic pool in the A2/O treatment systems significantly outnumbered the other stages. Meanwhile, influent organic matter within the range >0.45 μm, 10–30, 5–10, and <1 k was well removed while organic matter in the MW range of 30–100 and 1–3 k was used at a low rate during A2/O treatment. Denitrification required an external carbon source in 30 mg/L (calculated as methanol) for ensuring efficient process operation. Experimental approaches in this study can be applied to evaluate and diagnose the function of water treatment process.
Keywords: Molecular weight distribution; Organic matter; Wastewater treatment; Continuous filtration

Gamma irradiation and steam pretreatment of jute stick powder for the enhancement of dye adsorption efficiency by Fahmida Parvin; Nargis Sultana; S. M. Ahsan Habib; Nikhil Chandra Bhoumik (3503-3510).
The aim of this study is to find out the facile and effective pretreatment technique to enhance the capacity of jute stick powder (JSP) in adsorbing dye from raw textile effluent. Hence, different pretreatment techniques, i.e., radiation treatment, alkali treatment, ammonia treatment, steam treatment and CaCl2 treatment were applied to JSP and the adsorbing performance were examined for synthetic dye solutions (Blue FCL and Red RL dye). Different gamma radiation doses were applied on JSP and optimum dye removal efficiency was found at 500 krad in removing these two dyes (50 ppm) from solutions. Among the different pretreatment techniques, gamma irradiated JSP (500 Krad) exhibits highest dye uptake capacity for RED RL dye, whereas steam-treated JSP shows highest performance in adsorbing blue FCL dye. Subsequently, we applied the gamma irradiated and steam-treated JSP on real textile effluent (RTE) and these two techniques shows potentiality in adsorbing dye from raw textile effluent and in reducing BOD5, COD load and TOC to some extent as well. Fourier transform infrared spectroscopy (FTIR) analysis also proved that dye has been adsorbed on pretreated JSP.
Keywords: Jute stick powder pretreatment; Textile wastewater; Gamma radiation

Assessment of roadside surface water quality of Savar, Dhaka, Bangladesh using GIS and multivariate statistical techniques by Fahad Ahmed; A. N. M. Fakhruddin; MD. Toufick Imam; Nasima Khan; Abu Tareq Mohammad Abdullah; Tanzir Ahmed Khan; Md. Mahfuzur Rahman; Mohammad Nashir Uddin (3511-3525).
In this study, multivariate statistical techniques in collaboration with GIS are used to assess the roadside surface water quality of Savar region. Nineteen water samples were collected in dry season and 15 water quality parameters including TSS, TDS, pH, DO, BOD, Cl, F, NO3 2−, NO2 , SO4 2−, Ca, Mg, K, Zn and Pb were measured. The univariate overview of water quality parameters are TSS 25.154 ± 8.674 mg/l, TDS 840.400 ± 311.081 mg/l, pH 7.574 ± 0.256 pH unit, DO 4.544 ± 0.933 mg/l, BOD 0.758 ± 0.179 mg/l, Cl 51.494 ± 28.095 mg/l, F 0.771 ± 0.153 mg/l, NO3 2− 2.211 ± 0.878 mg/l, NO2 4.692 ± 5.971 mg/l, SO4 2− 69.545 ± 53.873 mg/l, Ca 48.458 ± 22.690 mg/l, Mg 19.676 ± 7.361 mg/l, K 12.874 ± 11.382 mg/l, Zn 0.027 ± 0.029 mg/l, Pb 0.096 ± 0.154 mg/l. The water quality data were subjected to R-mode PCA which resulted in five major components. PC1 explains 28% of total variance and indicates the roadside and brick field dust settle down (TDS, TSS) in the nearby water body. PC2 explains 22.123% of total variance and indicates the agricultural influence (K, Ca, and NO2 ). PC3 describes the contribution of nonpoint pollution from agricultural and soil erosion processes (SO4 2−, Cl, and K). PC4 depicts heavy positively loaded by vehicle emission and diffusion from battery stores (Zn, Pb). PC5 depicts strong positive loading of BOD and strong negative loading of pH. Cluster analysis represents three major clusters for both water parameters and sampling sites. The site based on cluster showed similar grouping pattern of R-mode factor score map. The present work reveals a new scope to monitor the roadside water quality for future research in Bangladesh.
Keywords: Surface water; Principal component analysis; Cluster analysis; Geographical information system (GIS); Savar

This paper presents the development of multi-objective Genetic Algorithms to optimize chlorination design and management in drinking water networks (DWN). Three objectives have been considered: the improvement of the chlorination uniformity (healthy objective), the minimization of chlorine booster stations number, and the injected chlorine mass (economic objectives). The problem has been dissociated in medium and short terms ones. The proposed methodology was tested on hypothetical and real DWN. Results proved the ability of the developed optimization tool to identify relationships between the healthy and economic objectives as Pareto fronts. The proposed approach was efficient in computing solutions ensuring better chlorination uniformity while requiring the weakest injected chlorine mass when compared to other approaches. For the real DWN studied, chlorination optimization has been crowned by great improvement of free-chlorine-dosing uniformity and by a meaningful chlorine mass reduction, in comparison with the conventional chlorination.
Keywords: Multi-objective; Optimization; Chlorination; Uniformity; Genetic Algorithms; Drinking water networks

Environmental quality assessment of groundwater resources in Al Jabal Al Akhdar, Sultanate of Oman by Mohammed Saif Al-Kalbani; Martin F. Price; Mushtaque Ahmed; Asma Abahussain; Timothy O’Higgins (3539-3552).
The research was conducted to assess the quality of groundwater resources of Al Jabal Al Akhdar, Oman. 11 drinking water sources were sampled during summer and winter seasons during 2012–2013 to evaluate their physico-chemical quality indicators; and assess their suitability for drinking and other domestic purposes. Sample collection, handling and processing followed the standard methods recommended by APHA and analyzed in quality assured laboratories using appropriate analytical methods and instrumental techniques. The results show that the quality parameters in all drinking water resources are within the permissible limits set by Omani and WHO standards; and the drinking water quality index is good or medium in quality based on NFS-WQI classification criteria, indicating their suitability for human consumption. There is an indication of the presence of high nitrate concentrations in some groundwater wells, which require more investigations and monitoring program to be conducted on regular basis to ensure good quality water supply for the residents in the mountain. The trilinear Piper diagram shows that most of the drinking water resources of the study area fall in the field of calcium and bicarbonate type with some magnesium bicarbonate type indicating that most of the major ions are natural in origin due to the geology of the region. This study is a first step towards providing indicators on groundwater quality of this fragile mountain ecosystem, which will be the basis for future planning decisions on corrective demand management measures to protect groundwater resources of Al Jabal Al Akhdar.
Keywords: Groundwater; Piper trilinear diagram; Water quality index; Hydrochemistry; Al Jabal Al Akhdar; Oman

Ground water quality evaluation in the lean period of a mining township by Bably Prasad; Deblina Maiti; Adarsh Kumar (3553-3560).
Groundwater of mining towns is very much affected due to mining activity. During mining of mineral from underground, huge quantity of ground water is pumped out to make mining possible. Groundwater samples have been collected from the 20 sampling sites of Dhanbad, a mining Township, in the lean period (summer) of the years 2011 and 2014. Four samples have been obtained from open well and 16 from hand pumps. Water quality parameters such as pH, total hardness, Ca hardness, Mg Hardness, chloride, sulphate, total dissolved solids, and heavy metals have been evaluated. The values of pH, total hardness, Ca hardness, Mg hardness, chloride, sulphate, and total dissolved solids have increased in 2014 as compared to 2011 which may be due to increase in mineral content in the lean period and decrease in the rate of recharge of aquifers in 2014. The concentration of heavy metals has decreased in 2014 as compared to 2011 which may be due to less leaching of heavy metals from the ground strata. From the overall study, it has been concluded that most of the water quality parameters of all the 20 groundwater samples in the year 2014 are not exceeding the acceptable concentration level, as mentioned in Indian drinking water specifications. Groundwater in the year 2014 has not shown any significant change in its quality as compared to the year 2011. In the incoming years, quality of groundwater will not show any drastic change unless and until any anthropogenic activity other than mining will affect it.
Keywords: Groundwater; Water quality parameters; Coal mining; Heavy metals; Heavy metal pollution index

Sustainable conversion of agro-wastes into useful adsorbents by Olugbenga Solomon Bello; Emmanuel Seun Owojuyigbe; Monsurat Abiodun Babatunde; Folasayo Eunice Folaranmi (3561-3571).
Preparation and characterization of raw and activated carbon derived from three different selected agricultural wastes: kola nut pod raw and activated (KNPR and KNPA), bean husk raw and activated (BHR and BHA) and coconut husk raw and activated (CHR and CHA) were investigated, respectively. Influences of carbonization and acid activation on the activated carbon were investigated using SEM, FTIR, EDX, pHpzc and Boehm titration techniques, respectively. Carbonization was done at 350 °C for 2 h followed by activation with 0.3 M H3PO4 (ortho-phosphoric acid). Results obtained from SEM, FTIR, and EDX revealed that, carbonization followed by acid activation had a significant influence on morphology and elemental composition of the samples. SEM showed well-developed pores on the surface of the precursors after acid treatment, FTIR spectra revealed reduction, broadening, disappearance or appearance of new peaks after acid activation. EDX results showed highest percentage of carbon by atom respectively in the order BHA > KNPA > CHA respectively. The pHpzc was found to be 5.32, 4.57 and 3.69 for KNPA, BHA and CHA, respectively. Boehm titration result compliments that of pHpzc, indicating that the surfaces of the prepared adsorbents are predominantly acidic. This study promotes a sustainable innovative use of agro-wastes in the production of cheap and readily available activated carbons, thereby ensuring more affordable water and effluent treatment adsorbents.
Keywords: Activation; Adsorbent; Bean husk; Coconut husk; Kola nut pod

Removal of the methyl violet 2B dye from aqueous solution using sustainable adsorbent Artocarpus odoratissimus stem axis by Muhammad Raziq Rahimi Kooh; Muhammad Khairud Dahri; Linda B. L. Lim (3573-3581).
This study investigates the potential of the stem axis of Artocarpus odoratissimus fruit (TSA) as an adsorbent for the removal of methyl violet 2B (MV). The functional group analysis was carried out using Fourier-transform infrared spectroscopy. Investigation of the effects of pH and ionic strength provide insights on the involvement of electrostatic attraction and hydrophobic–hydrophobic attraction between the adsorbent and adsorbates. Kinetics models (pseudo-first-order, pseudo-second-order, Weber–Morris and Boyd) and isotherm models (Langmuir, Freundlich and Dubinin–Raduskevich) were used for characterising the adsorption process. The Langmuir model predicted a high q m of 263.7 mg g−1. Thermodynamics studies indicate the adsorption system is spontaneous, endothermic and physical sorption dominant. The spent adsorbent was successfully regenerated using water and obtained adsorption capacity close to the unused adsorbent even after fifth cycle of washing.
Keywords: Biosorption; Artocarpus odoratissimus (tarap); Methyl violet 2B; Hydrophobic–hydrophobic interaction; Electrostatic interaction

Recharge source identification using isotope analysis and groundwater flow modeling for Puri city in India by P. C. Nayak; S. V. Vijaya Kumar; P. R. S. Rao; T. Vijay (3583-3598).
The holy city of Lord Jagannath is situated on the sea shore of the Bay of Bengal in Odisha state in India. Puri is a city of high religious importance and heritage value, details of the rituals, fairs, and festivals, and related aspects are covered extensively. It is found that water levels in two wells (Ganga and Yamuna) are declining and the causes are studied by undertaking modeling study of rainfall-recharge processes, surface water–groundwater interactions, and increasing demands due to urbanization at basin scale. Hydrochemical analysis of groundwater samples indicates that pH value is varying from 7 to 8.4 and electrical conductivity (EC) is found in between 238 and 2710 μmhos/cm. The EC values indicate that the shallow groundwater in Puri is not saline. Stable isotopic signatures of O-18, Deuterium indicate two different sources are active in the city area. In most of the handpumps, water recharged by the surface water sources. From the current investigation, it is evident that in a few handpumps and most of the dug-wells, isotopic signatures of water samples resembles with local precipitation. The groundwater recharge is taking place from the north-southern direction. Visual MODFLOW has been used for studying groundwater aspects and different scenarios have been developed. It is suggested to maintain water level in Samang Lake to restore depletion in groundwater level in two wells.
Keywords: Groundwater; Isotope analysis; Recharge; Flow modeling; MODFLOW

Hydrochemistry and quality assessment of groundwater in the Ardabil area, Iran by N. Aghazadeh; M. Chitsazan; Y. Golestan (3599-3616).
In the study area, groundwater is the main water resource for various purposes such as drinking, agriculture and industrial. To evaluate the hydrochemical characteristics of groundwater and suitability for drinking, irrigation and industrial purposes, seventy-seven samples were collected and analyzed for various ions. Results show that, groundwater in the study area is mainly hard to very hard, and slightly alkaline-fresh to brackish in nature. According to the hydrochemistry diagrams, the main groundwater types are Ca, Mg-HCO3, Na-HCO3 and Na-Cl. Calculation of mineral saturation index indicate that the groundwater samples are saturated with respect to carbonate minerals and under-saturated with respect to sulfate minerals such as gypsum and anhydride. The mineral weathering, mixing, ion exchange and anthropogenic activity are the dominant hydrogeochemical natural processes. Results of investigating the quality of heavy metals and calculating the heavy metal index indicated that the groundwater of study area is not contaminated with heavy metals. In this research, the various indices were used to determine the quality of groundwater for various uses. Calculate the indices and comparison results with the WHO standards to determine the quality of groundwater for various uses indicated that the most of the groundwater in study area is chemically suitable for drinking, industrial and agricultural uses.
Keywords: Ardabil; Groundwater quality; Heavy metals; Hydrochemistry; Hydrogeochemical processes

Removal efficiency of nickel and lead from industrial wastewater using microbial desalination cell by Fariba Mirzaienia; Ali Asadipour; Ahmad Jonidi Jafari; Mohammad Malakootian (3617-3624).
Microbial desalination cell (MDC) is a new method of desalination. Its energy is supplied through microbial metabolism of organic materials. In this study, synthetic samples were provided with concentration of 25, 50, 75, 100 mg/L Ni and Pb. Removal efficiency of each metal was analyzed after 60, 90, 120 min, psychrophilic, mesophilic, thermophilic and 3–4, 4–5, 5–6 mg/L dissolved oxygen. Optimum conditions for removing Ni and Pb were achieved in 100, 4.5 and 4.6 mg/L dissolved oxygen, respectively, 26 °C and 120 min. Nickel and led were removed from wastewaters of Isfahan electroplating industry and steel company. The maximum removal efficiencies of Ni and Pb in real samples were 68.81 and 70.04%. MDC can be considered as a good choice for removing Ni and Pb from industrial wastewater. Due to microorganisms for decomposing organic material in municipal wastewater, metals from industrial wastewater can be removed simultaneously.
Keywords: Microbial desalination cell; Isfahan electroplating wastewater; Isfahan steel company wastewater

Removal of Cr(VI) from groundwater by Fe(0) by Yanjiao Gao; Rui Liu (3625-3631).
This research was conducted to investigate the treatment of hexavalent chromium (Cr(VI)) by iron powder (Fe(0)) columns of simulated permeable reactive barriers with and without calcium carbonate (CaCO3). Two columns filled with Fe(0) were used as Cr(VI) removal equipment running at a flow velocity of 10 ml/min at room temperature. After 200 days running of the two columns, the results showed that Fe(0) was an effective material for Cr(VI) reduction with an average removal rate of above 84.6%. The performance of Column 2 with CaCO3 was better than Column 1 without CaCO3 in terms of average Cr(VI) removal rate. The presence of CaCO3 buffered the increasing pH caused by Fe(0) corrosion in Column 2 and enhanced the removal rate of Column 2. Scanning Electron Microscopy (SEM) images of Fe(0) in the three stages of running of the two columns illustrated that the coat layer of Column 1 was a little thicker than that of Column 2. Energy-dispersive spectrometry (EDS) results showed that the surface of Fe(0) of Column 2 contained more chromium elements. Raman spectroscopy found that all iron oxide was generated on the Fe(0) surface of Column 1 and Column 2 and chromium class objects were only detected on Fe(0) surface in Column 2.
Keywords: Groundwater; Hexavalent chromium; Calcium carbonate; Iron powder

The process of water quality testing is money/time-consuming, quite important and difficult stage for routine measurements. Therefore, use of models has become commonplace in simulating water quality. In this study, the coactive neuro-fuzzy inference system (CANFIS) was used to simulate groundwater quality. Further, geographic information system (GIS) was used as the pre-processor and post-processor tool to demonstrate spatial variation of groundwater quality. All important factors were quantified and groundwater quality index (GWQI) was developed. The proposed model was trained and validated by taking a case study of Mazandaran Plain located in northern part of Iran. The factors affecting groundwater quality were the input variables for the simulation, whereas GWQI index was the output. The developed model was validated to simulate groundwater quality. Network validation was performed via comparison between the estimated and actual GWQI values. In GIS, the study area was separated to raster format in the pixel dimensions of 1 km and also by incorporation of input data layers of the Fuzzy Network-CANFIS model; the geo-referenced layers of the effective factors in groundwater quality were earned. Therefore, numeric values of each pixel with geographical coordinates were entered to the Fuzzy Network-CANFIS model and thus simulation of groundwater quality was accessed in the study area. Finally, the simulated GWQI indices using the Fuzzy Network-CANFIS model were entered into GIS, and hence groundwater quality map (raster layer) based on the results of the network simulation was earned. The study’s results confirm the high efficiency of incorporation of neuro-fuzzy techniques and GIS. It is also worth noting that the general quality of the groundwater in the most studied plain is fairly low.
Keywords: GWQI; Model validation; Groundwater quality map; Mazandaran Plain

Adsorptive removal of crystal violet dye by a local clay and process optimization by response surface methodology by Amal Loqman; Brahim El Bali; Johannes Lützenkirchen; Peter G. Weidler; Abdelhak Kherbeche (3649-3660).
The current study relates to the removal of a dye [crystal violet (CV)] from aqueous solutions through batch adsorption experiment onto a local clay from Morocco. The clay was characterized by X-ray diffraction, IR spectroscopy, X-ray fluorescence, scanning electron microscope, Brunauer–Emmett–Teller analysis and Fraunhofer diffraction method. The influence of independent variables on the removal efficiency was determined and optimized by response surface methodology using the Box–Behnken surface statistical design. The model predicted maximum adsorption of 81.62% under the optimum conditions of operational parameters (125 mg L−1 initial dye concentration, 2.5 g L−1 adsorbent dose and time of 43 min). Practically, the removal ranges in 27.4–95.3%.
Keywords: Crystal violet; Clay; Box–Behnken design; Adsorption; Response surface methodology

Adsorption of two acid dyes named Acid orange 8 (AO8) and Acid violet 7 (AV7) by amine based polymer aniline formaldehyde condensate (AFC) was studied. Adsorption of both dyes was favored at acidic pH. Electrostatic attraction between protonated amine group (NH3 +) of AFC and anionic sulfonate group (SO3 ) of dye molecule along with hydrogen bond formation and interaction between aromatic group of dye and AFC were responsible mechanisms for dye uptake. Isotherm of AO8 was Type I and followed Langmuir isotherm model. AV7 isotherm on AFC was of Type III and followed Freundlich model. Kinetics study showed that external mass transfer was the rate limiting step followed by intraparticle diffusion. Maximum adsorption capacities of AO8 and AV7 were observed as 164 and 68 mg/g. AO8 dye being smaller in molecular size was adsorbed more due to higher diffusion rate and higher dye: AFC ratio, which enhanced the interaction between dye and polymer.
Keywords: Acid azo dyes; Aniline formaldehyde condensate; Type I isotherm; Type III isotherm; External mass transfer; Dye:AFC ratio

A question regarding how organic matters in water are associated with hardness salts hasn’t been completely studied. For partially clarifying this question, a water fractional separation and investigation method has been recommended. The experiments carried out by the recommended method showed that the dynamics of the distribution of total hardness and permanganate oxidation values in the fractions of frozen and melted water samples coincided completely based on which it has been concluded that organic matters in natural waters are associated with hardness salts and always distributed in this form. All these findings are useful information for the deep study of macro- and microelements in water.
Keywords: Water freezing–melting method; Fractional separation of water impurities; Total hardness; Permanganate oxidation; Hardness salt and organic matter distribution

Classification of heavy metal ions present in multi-frequency multi-electrode potable water data using evolutionary algorithm by Rashmi Karkra; Prashant Kumar; Baban K. S. Bansod; Sudeshna Bagchi; Pooja Sharma; C. Rama Krishna (3679-3689).
Access to potable water for the common people is one of the most challenging tasks in the present era. Contamination of drinking water has become a serious problem due to various anthropogenic and geogenic events. The paper demonstrates the application of evolutionary algorithms, viz., particle swan optimization and genetic algorithm to 24 water samples containing eight different heavy metal ions (Cd, Cu, Co, Pb, Zn, Ar, Cr and Ni) for the optimal estimation of electrode and frequency to classify the heavy metal ions. The work has been carried out on multi-variate data, viz., single electrode multi-frequency, single frequency multi-electrode and multi-frequency multi-electrode water samples. The electrodes used are platinum, gold, silver nanoparticles and glassy carbon electrodes. Various hazardous metal ions present in the water samples have been optimally classified and validated by the application of Davis Bouldin index. Such studies are useful in the segregation of hazardous heavy metal ions found in water resources, thereby quantifying the degree of water quality.
Keywords: Genetic algorithm; Particle swarm optimization; Heavy metal ions; Water quality; Multi-electrode; Multi-frequency

A new approach to flow simulation using hybrid models by Abazar Solgi; Heidar Zarei; Vahid Nourani; Ramin Bahmani (3691-3706).
The necessity of flow prediction in rivers, for proper management of water resource, and the need for determining the inflow to the dam reservoir, designing efficient flood warning systems and so forth, have always led water researchers to think about models with high-speed response and low error. In the recent years, the development of Artificial Neural Networks and Wavelet theory and using the combination of models help researchers to estimate the river flow better and better. In this study, daily and monthly scales were used for simulating the flow of Gamasiyab River, Nahavand, Iran. The first simulation was done using two types of ANN and ANFIS models. Then, using wavelet theory and decomposing input signals of the used parameters, sub-signals were obtained and were fed into the ANN and ANFIS to obtain hybrid models of WANN and WANFIS. In this study, in addition to the parameters of precipitation and flow, parameters of temperature and evaporation were used to analyze their effects on the simulation. The results showed that using wavelet transform improved the performance of the models in both monthly and daily scale. However, it had a better effect on the monthly scale and the WANFIS was the best model.
Keywords: Flow simulation; Hybrid models; Wavelet transform; Gamasiyab River

The transport groundwater modelling has been undertaken to assess potential remediation scenarios and provide an optimal remediation options for consideration. The purpose of the study was to allow 50 years of predictive remediation simulation time. The results depict the likely total petroleum hydrocarbon migration pattern in the area under the worst-case scenario. The remediation scenario simulations indicate that do nothing approach will likely not achieve the target water quality within 50 years. Similarly, complete source removal approach will also likely not achieve the target water quality within 50 years. Partial source removal could be expected to remove a significant portion of the contaminant mass, but would increase the rate of contaminant recharge in the short to medium term. The pump–treat–reinject simulation indicates that the option appears feasible and could achieve a reduction in the area of the 0.01 mg/L TPH contour area for both Raudhatain and Umm Al-Aish by 35 and 30%, respectively, within 50 years. The rate of improvement and the completion date would depend on a range of factors such as bore field arrangements, pumping rates, reinjection water quality and additional volumes being introduced and require further optimisation and field pilot trials.
Keywords: Contamination; Oil; Hydrocarbon; Pollution; Groundwater remediation; Numerical modelling; Persian Gulf; Iraq war

Central Composite Design (CCD) applied for statistical optimization of glucose and sucrose binary carbon mixture in enhancing the denitrification process by Jun-Wei Lim; Hoe-Guan Beh; Dennis Ling Chuan Ching; Yeek-Chia Ho; Lavania Baloo; Mohammed J. K. Bashir; Seng-Kew Wee (3719-3727).
The present study provides an insight into the optimization of a glucose and sucrose mixture to enhance the denitrification process. Central Composite Design was applied to design the batch experiments with the factors of glucose and sucrose measured as carbon-to-nitrogen (C:N) ratio each and the response of percentage removal of nitrate–nitrogen (NO3 –N). Results showed that the polynomial regression model of NO3 –N removal had been successfully derived, capable of describing the interactive relationships of glucose and sucrose mixture that influenced the denitrification process. Furthermore, the presence of glucose was noticed to have more consequential effect on NO3 –N removal as opposed to sucrose. The optimum carbon sources mixture to achieve complete removal of NO3 –N required lesser glucose (C:N ratio of 1.0:1.0) than sucrose (C:N ratio of 2.4:1.0). At the optimum glucose and sucrose mixture, the activated sludge showed faster acclimation towards glucose used to perform the denitrification process. Later upon the acclimation with sucrose, the glucose uptake rate by the activated sludge abated. Therefore, it is vital to optimize the added carbon sources mixture to ensure the rapid and complete removal of NO3 –N via the denitrification process.
Keywords: Denitrification; Carbon source; C:N ratio; Central Composite Design; Optimization

New core@shell nanogel based 2-acrylamido-2-methyl-1-propane sulfonic acid for preconcentration of Pb(II) from various water samples by Kamel Rizq Shoueir; Magda Ali Akl; Ali Ali Sarhan; Ayman Mohamdy Atta (3729-3740).
Poly(vinyl alcohol) core coated with poly(2-acrylamido-2-methyl-1-propanesulfonic acid-co-N-isopropylacrylamide) shell to produce well-define PVA@P(AMPS-co-NIPAm) core shell nanogels with a core of 25 ± 0.5 nm and shell of 5 ± 0.5 nm. The synthetic approach was produced by a surfactant free emulsion polymerization (SFEP). The specific area was found to be 1685.8 m2/g. The nanogels were studied in a batch adsorption for removal of Pb(II) ions and characterized by SEM, TEM, TGA and BET measurements. The results showed that the adsorption equilibrium data fitted the Langmuir isotherm and the kinetic studies are well described by the pseudo-second-order kinetic model. The Pb(II) maximum adsorption was 510.2 (mg/g) for PVA@P(90AMPS-co-10NIPAm) (wt.: wt%). The PVA@P(AMPS-co-NIPAm) nanogels were applied for extracting of Pb(II) in real different environmental water samples successfully with high recoveries reaches 104.4%.
Keywords: Nanostructures; Chemical synthesis; Transmission electron microscopy (TEM); Surface properties

A non-steady-state mathematical model system for the kinetics of adsorption and biodegradation of 2-chlorophenol (2-CP) by attached and suspended biomass on activated carbon process was derived. The mechanisms in the model system included 2-CP adsorption by activated carbon, 2-CP mass transport diffusion in biofilm, and biodegradation by attached and suspended biomass. Batch kinetic tests were performed to determine surface diffusivity of 2-CP, adsorption parameters for 2-CP, and biokinetic parameters of biomass. Experiments were conducted using a biological activated carbon (BAC) reactor system with high recycled rate to approximate a completely mixed flow reactor for model verification. Concentration profiles of 2-CP by model predictions indicated that biofilm bioregenerated the activated carbon by lowering the 2-CP concentration at the biofilm-activated carbon interface as the biofilm grew thicker. The removal efficiency of 2-CP by biomass was approximately 98.5% when 2-CP concentration in the influent was around 190.5 mg L−1 at a steady-state condition. The concentration of suspended biomass reached up to about 25.3 mg L−1 while the thickness of attached biomass was estimated to be 636 μm at a steady-state condition by model prediction. The experimental results agree closely with the results of the model predictions.
Keywords: Adsorption; Biodegradation; 2-chlorophenol; Biological activated carbon (BAC); Kinetic model

Water quality of Al-Gharraf river, the largest branch of Tigris River south of Iraq, was evaluated by the National Sanitation Foundation Water Quality Index (NFS WQI) and the Heavy Metal Pollution Index (HPI) depending on 13 physical, chemical, and biological parameters of water quality measured monthly at ten stations on the river during 2015. The NSF-WQI range obtained for the sampling sites was 61–70 indicating a medium water quality. The HPI value was 98.6 slightly below the critical value for drinking water of 100, and the water quality in the upstream stations is better than downstream due to decrease in water and the accumulation of contaminants along the river. This study explains the significance of applying the water quality indices that show the aggregate impact of ecological factors in charge of water pollution of surface water and which permits translation of the monitoring data to assist the decision makers.
Keywords: NSF-WQI; HPI; Water quality index; Al-Gharraf river

Morphological and morphotectonic analyses have been used to obtain information that influence hydrographic basins, predominantly these are modifications of tectonic elements and the quantitative description of landforms. Discrimination of morphotectonic indices of active tectonics of the Jamini river basin consists the analyses of asymmetry factor, ruggedness number, basin relief, gradient, basin elongation ratio, drainage density analysis, and drainage pattern analysis, which have been completed for each drainage basin using remote sensing and GIS techniques. The Jamini river is one of the major tributaries of the Betwa river in central India. The Jamini river basin is divided into five subwatersheds viz. Jamrar, Onri, Sainam, Shahzad and Baragl subwatershed. The quantitative approach of watershed development of the Jamini river basin, and its four sixth (SW1-SW4) and one fifth (SW5) order subwatersheds, was carried out using Survey of India toposheets (parts of 54I, 54K, 54L, 54O, and 54P), Landsat 7 ETM+, ASTER (GDEM) data, and field data. The Jamini river has low bifurcation index which is a positive marker of tectonic imprint on the hydrographic network. The analyses show that the geomorphological progression of the study area was robustly influenced by tectonics. The analysis demonstrates to extensional tectonics system with the following alignments: NE–SW, NW–SE, NNE–SSW, ENE–WSW, E–W, and N–S. Three major trends are followed by lower order streams viz. NE–SW, NW–SE, and E–W directions which advocate that these tectonic trends were active at least up to the Late Pleistocene. The assessment of morphotectonic indices may be used to evaluate the control of active faults on the hydrographic system. The analysis points out westward tilting of the drainage basins with strong asymmetry in some reaches, marked elongation ratio of subwatersheds, and lower order streams having close alignment with lineaments (active faults). The study facilitated to considerate the function of active tectonism in the advancement of the basin.
Keywords: Jamini river; Morphotectonics; Remote Sensing and GIS technique; Central India

The current work demonstrates the support vector machine (SVM) and adaptive neuro-fuzzy inference system (ANFIS) modeling to assess the removal efficiency of Kjeldahl Nitrogen of a full-scale aerobic biological wastewater treatment plant. The influent variables such as pH, chemical oxygen demand, total solids (TS), free ammonia, ammonia nitrogen and Kjeldahl Nitrogen are used as input variables during modeling. Model development focused on postulating an adaptive, functional, real-time and alternative approach for modeling the removal efficiency of Kjeldahl Nitrogen. The input variables used for modeling were daily time series data recorded at wastewater treatment plant (WWTP) located in Mangalore during the period June 2014–September 2014. The performance of ANFIS model developed using Gbell and trapezoidal membership functions (MFs) and SVM are assessed using different statistical indices like root mean square error, correlation coefficients (CC) and Nash Sutcliff error (NSE). The errors related to the prediction of effluent Kjeldahl Nitrogen concentration by the SVM modeling appeared to be reasonable when compared to that of ANFIS models with Gbell and trapezoidal MF. From the performance evaluation of the developed SVM model, it is observed that the approach is capable to define the inter-relationship between various wastewater quality variables and thus SVM can be potentially applied for evaluating the efficiency of aerobic biological processes in WWTP.
Keywords: ANFIS; SVM; Statistical indices; Total Kjeldahl Nitrogen; Wastewater treatment plants; Membership function

Photocatalytically modified ceramic adsorbents were synthesized for the removal of high concentration Cu (II) and Co (II) ions from their aqueous solutions. The raw material, diatomaceous aluminosilicate mineral was modified using silver and anatase titanium oxide nanoparticles. Batch adsorption experiment was carried out on the targeted metal ions and the results were analyzed by the Langmuir and Freundlich equation at different concentrations (100–1000 mg/l) and the characteristic parameters for each adsorption isotherm were determined. As-received raw materials do not exhibit any sorption capacity for high concentration Cu2+ and Co2+ adsorbates. However, the adsorption isotherms for modified diatomaceous ceramic adsorbents could be fitted well by the Langmuir model for both Cu2+ and Co2+ with correlation coefficient (R) of up to 0.99953. The highest and lowest monolayer coverage (q max) were 121.803 and 31.289 mg/g for Cu2+ and Co2+, respectively. The separation factor (R L) in the experiment was less than one (<1), indicating that the adsorption of metal ions on the Ag–TiO2-modified ceramic adsorbent is favorable. The highest adsorption capacity (K f) and intensity (n) constants obtained from Freundlich model are 38.832 (Cu2+ on ZEO-T) and 5.801 (Co2+ on STOX-Z).
Keywords: Diatomaceous ceramic; Adsorption capacity; Freundlich; Spectrophotometry; Langmuir; Separation factor

Influence of geochemical processes on hydrochemistry and irrigation suitability of groundwater in part of semi-arid Deccan Plateau, India by Duraisamy Vasu; Surendra Kumar Singh; Pramod Tiwary; Nisha Sahu; Sanjay Kumar Ray; Pravin Butte; Veppangadu Perumal Duraisami (3803-3815).
Major ion geochemistry was used to characterise the chemical composition of groundwater in part of semi-arid Deccan plateau region to understand the geochemical evolution and to evaluate the groundwater quality for irrigation. The study area comprises peninsular gneissic complex of Archean age, younger granites and basaltic alluvium. Forty-nine georeferenced groundwater samples were collected and analysed for major ions. The ionic sequence based on relative proportions was Na+ > Mg2+ > Ca2+ > SO4 2− > HCO3  > Cl > CO3 2− > BO3 3− > K+. High Na+, Mg2+ and Ca2+ were generally associated with basaltic alluvial formation, whereas pH, electrical conductivity (EC) and total dissolved salts (TDS) were found to be higher in granitic formations. High standard deviation for EC, TDS, Na+, Ca2+ and Mg2+ indicated the dispersion of ionic concentration throughout the study area. Four major hydrochemical facies identified were Na-Mg-HCO3 type; Mg-Na-HCO3 type; Na-Mg-Ca-SO4 and Mg-Na-Ca-SO4 type. The graphical plots indicated that the groundwater chemistry was influenced by rock–water interaction, silicate weathering and reverse ion exchange. Sodium-dominated waters might have impeded the hydraulic properties of soils as a result of long-term irrigation.
Keywords: Hydrogeochemistry; Groundwater quality; Deccan plateau; Silicate weathering; Rock–water interaction

Brown algae (Phaeophyta) for monitoring heavy metals at the Sudanese Red Sea coast by Abuagla Y. A. Ali; Abubakr M. Idris; Ammar M. Ebrahim; Mohmaed A. H. Eltayeb (3817-3824).
This study aimed at monitoring some heavy metals at the Sudanese Red Sea coast using Brown algae (Phaeophyta) as biomonitor. The total contents of heavy metals in four species (Turbinaria sp., Sargassum sp., Cystoseira sp. and Padina sp.) as well as seawater were examined. Twenty-six algae samples were collected from seven locations. The ranges of concentrations (µg/g, dry wt.) of heavy metals in algae were 4.95–16.95 for Cr, 2.93–257.32 for Mn, 1.35–7.43 for Ni, 0.83–14.10 for Cu, 4.13–19.13 for Zn, 0.03–0.15 for Cd and 0.45–2.18 for Pb. The ranges of the pH and the salinity of seawater from the same locations were 8.11–8.82 and 38.00–41.00 PSU, respectively. The ranges of concentrations (µg/L) of heavy metals in seawater were 7.00–11.00 for Cr, 2.90–10.20 for Mn, 6.70–10.10 for Ni, 1.70–5.00 for Cu, 0.94–5.70 for Zn, 0.09–0.14 for Cd and 0.93–1.80 for Pb. No significant correlations between metal concentrations in algae and seawater were observed. Some locations in the study area recorded relatively high levels of heavy metals in algae indicating possible contribution from manmade activities. Cr recorded higher levels in the study area than those in other coastal areas in the word. Padina sp. and Cystoseira sp. were better bioindicator than Turbinaria sp., Sargassum sp. for their high metal uptake.
Keywords: Biomonitoring; Heavy metals; Phaeophyta; Red Sea

Quantitative analysis and implications of drainage morphometry of the Agula watershed in the semi-arid northern Ethiopia by Ayele Almaw Fenta; Hiroshi Yasuda; Katsuyuki Shimizu; Nigussie Haregeweyn; Kifle Woldearegay (3825-3840).
This study aimed at quantitative analysis of morphometric parameters of Agula watershed and its sub-watersheds using remote sensing data, geographic information system, and statistical methods. Morphometric parameters were evaluated from four perspectives: drainage network, watershed geometry, drainage texture, and relief characteristics. A sixth-order river drains Agula watershed and the drainage network is mainly dendritic type. The mean bifurcation ratio (R b) was 4.46 and at sub-watershed scale, high R b values (R b > 5) were observed which might be expected in regions of steeply sloping terrain. The longest flow path of Agula watershed is 48.5 km, with knickpoints along the main river which could be attributed to change of lithology and major faults which are common along the rift escarpments. The watershed has elongated shape suggesting low peak flows for longer duration and hence easier flood management. The drainage texture analysis revealed fine drainage which implies the dominance of impermeable soft rock with low resistance against erosion. High relief and steep slopes dominates, by which rough landforms (hills, breaks, and low mountains) make up 76% of the watershed. The S-shaped hypsometric curve with hypsometric integral of 0.4 suggests that Agula watershed is in equilibrium or mature stage of geomorphic evolution. At sub-watershed scale, the derived morphometric parameters were grouped into three clusters (low, moderate, and high) and considerable spatial variability was observed. The results of this study provide information on drainage morphometry that can help better understand the watershed characteristics and serve as a basis for improved planning, management, and decision making to ensure sustainable use of watershed resources.
Keywords: Morphometric analysis; Watershed characteristics; Remote sensing; Geographic information system; Semi-arid; Ethiopia

Efficient photodegradation of methyl violet dye using TiO2/Pt and TiO2/Pd photocatalysts by Khalid Saeed; Idrees Khan; Tamanna Gul; Mohammad Sadiq (3841-3848).
Titanium oxide supported palladium (TiO2/Pd) and titanium oxide supported platinum (TiO2/Pt) nanoparticles were prepared from their precursors through the incipient wetness method. The TiO2/Pd and TiO2/Pt nanoparticles were characterized by scanning electron microscopy (SEM), and energy dispersive X-rays (EDX), while the photodegradation study of methyl violet was performed by UV/VIS spectrophotometry. The morphological study shows that the Pd and Pt were well deposited on the surface of TiO2, which was confirmed by EDX. Both TiO2/Pd and TiO2/Pt nanoparticles were used as photocatalysts for the photodegradation of methyl violet in aqueous media under UV-light irradiation. The photodegradation study revealed that the TiO2/Pd and TiO2/Pt nanoparticles degraded about 95 and 78% of dye within 20 min, respectively. The effect of various parameters such as catalyst dosage, concentration of dye, and medium on the photocatalytic degradation was examined. The activity of recovered TiO2/Pd and TiO2/Pt nanoparticles was studied.
Keywords: TiO2 ; Photodegradation; Methyl violet; Photocatalyst

Study on a stepped eco-filter for treating greywater from single farm household by Jianjun Chen; Zaiyi Liao; Shaoyong Lu; Guangcai Hu; Yaoxin Liu; Cilai Tang (3849-3857).
A stepped eco-filter based greywater treating facility was built on-site in a typical farm house of China. This study was aimed to investigate the hydraulic loading rate (HLR) for the optimal removal efficiency and to analyze the processing performance throughout an entire year. The results showed that, the average value of TP from the influent was much lower while the linear alkylbenzene sulfonate was a little higher compared with other related studies. The removal rates of the indexes were all showed a distinct decline and dropped to a low level while the HLR was raised from 0.2 m3/(m2 day) to 0.4 m3/(m2 day). Therefore, the optimal HLR of the process ought to be in the range of 0.2–0.4 m3/(m2 day). The average system removal rates in summer were all higher than that in winter, but the facility still performed well in winter. Clogging has never occurred in the facility during the operation over an entire year. Together with the good performance, advantaged of lower cost and easier maintenance, this process has shown good applicability for greywater treatment in rural area.
Keywords: Greywater; Eco-filter; Farm household; Hydraulic loading rate; Linear alkylbenzene sulfonate

Removal of methyl violet 2B dye from aqueous solution using Nepenthes rafflesiana pitcher and leaves by Muhammad Raziq Rahimi Kooh; Muhammad Khairud Dahri; Linda B. L. Lim (3859-3868).
This study reported Nepenthes rafflesiana pitcher (NP) and Nepenthes rafflesiana leaves (NL) as new adsorbents for methyl violet (MV) dye. The experiments were done using 2 h contact time and without any pH alteration (pH 4.4). The effects of pH and ionic strength revealed hydrophobic–hydrophobic interaction as the predominant force of dye interaction with the adsorbent. Both NP-MV and NL-MV followed pseudo-second-order model indicating the adsorption processes may be governed by chemical process. Weber–Morris intraparticle diffusion model verified that the rate-limiting step of both the NP-MV and NL-MV systems is not intraparticle diffusion. The Langmuir model best described the adsorption process with high maximum monolayer adsorption (q m) of 288.7 and 194.0 mg g−1 for NP-MV and NL-MV, respectively. Thermodynamics studies revealed both NP-MV and NL-MV systems are spontaneous and endothermic in nature. From the regeneration study, it was found that NP’s and NL’s adsorption capacities could be recovered using distilled water and base whereby distilled water was able to recover 78% (NP) and 71% (NL) while base was able to recover 82% for both samples after three regeneration cycles.
Keywords: Nepenthes rafflesiana (Pitcher plant); Methyl violet 2B; Adsorption

Weather forecasting based on hybrid neural model by Tanzila Saba; Amjad Rehman; Jarallah S. AlGhamdi (3869-3874).
Making deductions and expectations about climate has been a challenge all through mankind’s history. Challenges with exact meteorological directions assist to foresee and handle problems well in time. Different strategies have been investigated using various machine learning techniques in reported forecasting systems. Current research investigates climate as a major challenge for machine information mining and deduction. Accordingly, this paper presents a hybrid neural model (MLP and RBF) to enhance the accuracy of weather forecasting. Proposed hybrid model ensure precise forecasting due to the specialty of climate anticipating frameworks. The study concentrates on the data representing Saudi Arabia weather forecasting. The main input features employed to train individual and hybrid neural networks that include average dew point, minimum temperature, maximum temperature, mean temperature, average relative moistness, precipitation, normal wind speed, high wind speed and average cloudiness. The output layer composed of two neurons to represent rainy and dry weathers. Moreover, trial and error approach is adopted to select an appropriate number of inputs to the hybrid neural network. Correlation coefficient, RMSE and scatter index are the standard yard sticks adopted for forecast accuracy measurement. On individual standing MLP forecasting results are better than RBF, however, the proposed simplified hybrid neural model comes out with better forecasting accuracy as compared to both individual networks. Additionally, results are better than reported in the state of art, using a simple neural structure that reduces training time and complexity.
Keywords: Weather forecasting; Flood control; Secure environment; Learning models; Time series analysis

A morphometric analysis of Sarabanga watershed in Salem district has been chosen for the present study. Geospatial tools, such as remote sensing and GIS, are utilized for the extraction of river basin and its drainage networks. The Shuttle Radar Topographic Mission (SRTM-30 m resolution) data have been used for morphometric analysis and evaluating various morphometric parameters. The morphometric parameters of Sarabanga watershed have been analyzed and evaluated by pioneer methods, such as Horton and Strahler. The dendritic type of drainage pattern is draining the Sarabanga watershed, which indicates that lithology and gentle slope category is controlling the study area. The Sarabanga watershed is covered an area of 1208 km2. The slope of the watershed is various from 10 to 40% and which is controlled by lithology of the watershed. The bifurcation ratio ranges from 3 to 4.66 indicating the influence of geological structure and suffered more structural disturbances. The form factor indicates elongated shape of the study area. The total stream length and area of watershed indicate that mean annual rainfall runoff is relatively moderate. The basin relief expressed that watershed has relatively high denudation rates. The drainage density of the watershed is low indicating that infiltration is more dominant. The ruggedness number shows the peak discharges that are likely to be relatively higher. The present study is very useful to plan the watershed management.
Keywords: Drainage; Linear; Aerial; Relief and watershed

Coagulation is an important process in drinking water treatment to attain acceptable treated water quality. However, the determination of coagulant dosage is still a challenging task for operators, because coagulation is nonlinear and complicated process. Feedback control to achieve the desired treated water quality is difficult due to lengthy process time. In this research, a hybrid of k-means clustering and adaptive neuro-fuzzy inference system (k-means-ANFIS) is proposed for the settled water turbidity prediction and the optimal coagulant dosage determination using full-scale historical data. To build a well-adaptive model to different process states from influent water, raw water quality data are classified into four clusters according to its properties by a k-means clustering technique. The sub-models are developed individually on the basis of each clustered data set. Results reveal that the sub-models constructed by a hybrid k-means-ANFIS perform better than not only a single ANFIS model, but also seasonal models by artificial neural network (ANN). The finally completed model consisting of sub-models shows more accurate and consistent prediction ability than a single model of ANFIS and a single model of ANN based on all five evaluation indices. Therefore, the hybrid model of k-means-ANFIS can be employed as a robust tool for managing both treated water quality and production costs simultaneously.
Keywords: k-means clustering; Adaptive neuro-fuzzy inference system; Artificial neural network; Coagulant dosage; Water quality; Modeling

Estimation of evapotranspiration (ET) is an essential component of the hydrologic cycle, which is also requisite for efficient irrigation water management planning and hydro-meteorological studies at both the basin and catchment scales. There are about twenty well-established methods available for ET estimation which depends upon various meteorological parameters and assumptions. Most of these methods are physically based and need a variety of input data. The FAO-56 Penman–Monteith method (PM) for estimating reference evapotranspiration (ET0) is recommend for irrigation scheduling worldwide, because PM generally yields the best results under various climatic conditions. This study investigates the abilities of artificial neural networks (ANN) to improve the accuracy of monthly evaporation estimation in sub-humid climatic region of Dehradun. In the first part of the study, different ANN models, comprising various combinations of training function and number of neutrons were developed to estimate the ET0 and it has been compared with the Penman–Monteith (PM) ET0 as the ideal (observed) ET0. Various statistical approaches were considered to estimate the model performance, i.e. Coefficient of Correlation (r), Sum of Squared Errors, Root Mean Square Error, Nash–Sutcliffe Efficiency Index (NSE) and Mean Absolute Error. The ANN model with Levenberg–Marquardt training algorithm, single hidden layer and nine number of neutron schema was found the best predicting capabilities for the study station with Coefficient of Correlation (r) and NSE value of 0.996 and 0.991 for calibration period and 0.990 and 0.980 for validation period, respectively. In the subsequent part of the study, the trend analysis of ET0 time series revealed a rising trend in the month of March, and a falling trend during June to November, except August, with more than 90% significance level and the annual declining rate was found to 1.49 mm per year.
Keywords: Evapotranspiration; Penman–Monteith; Neural networks; Mann–Kendall test

In the present work groundwater samples were collected from ten different data points in and around Jawaharnagar municipal dumpsite, Telangana State Hyderabad city from May 2015 to May 2016 on monthly basis for groundwater quality characterization. Pearson’s correlation coefficient (r) value was determined using correlation matrix to identify the highly correlated and interrelated water quality standards issued by Bureau of Indian Standard (IS-10500:2012). It is found that most of the groundwater samples are above acceptable limits and are not potable. The chemical analysis results revealed that pH range from 7.2 to 7.8, TA 222 to 427 mg/l, TDS 512 to 854 mg/l, TH 420 to 584 mg/l, Calcium 115 to 140 mg/l, Magnesium 55 to 115 mg/l, Chlorides 202 to 290 mg/l, Sulphates 170 to 250 mg/l, Nitrates 6.5 to 11.3 mg/l, and Fluoride 0.9 to 1.7 mg/l. All samples showed higher range of physicochemical parameters except nitrate content which was lower than permissible limit. Highly positive correlation was observed between pH–TH (r = 0.5063), TA–Cl (r = 0.5896), TDS–SO4 (r = 0.5125), Mg2+–NO3 (r = 0.5543) and Cl–F (r = 0.7786). The groundwater samples in and around Jawaharnagar municipal dumpsite implies that groundwater samples were contaminated by municipal leachate migration from open dumpsite. The results revealed that the systematic calculations of correlation coefficient between water parameters and regression analysis provide qualitative and rapid monitoring of groundwater quality.
Keywords: Groundwater; Dumpsite; Solid waste; Pearson correlation; Regression equation; Leachate

In order to understand the hydrological behavior of a catchment area, morphometric analysis of the drainage basin plays an important role to expresses the geology, geomorphology and structural antecedents. In the present study, morphometric analysis and its influence on hydrology were carried out in Makhawan watershed, Central India, using SRTM, remote sensing and GIS. SRTM data were used for preparation of DEM, slope and aspect maps. DEM was used to delineate the watershed limits and to extract the channel network, which was later updated using IRS 1D LISS III data. The hydrological module in ArcGIS was used for calculation of watershed and morphometric parameters, under linear, relief and aerial aspects. The watershed shows dendritic-to-sub-dendritic drainage pattern; however, parallel-to-sub-parallel pattern developed locally which may be due to rejuvenation of streams in mature stage with moderate drainage texture. High drainage density in the watershed is observed over impermeable subsurface material, sparse vegetation with high relief; whereas, low drainage density is found over permeable subsurface material and low relief. It has been found that low relief with low drainage density areas are favorable sites for more groundwater prospects.
Keywords: Morphometry; Hydrogeology; Watershed; Remote sensing; SRTM

Degradation of selected industrial dyes using Mg-doped TiO2 polyscales under natural sun light as an alternative driving energy by H. P. Shivaraju; G. Midhun; K. M. Anil Kumar; S. Pallavi; N. Pallavi; Shahmoradi Behzad (3937-3948).
Designing photocatalytic materials with modified functionalities for the utilization of renewable energy sources as an alternative driving energy has attracted much attention in the area of sustainable wastewater treatment applications. Catalyst-assisted advanced oxidation process is an emerging treatment technology for organic pollutants and toxicants in industrial wastewater. Preparation of visible-light-responsive photocatalyst such as Mg-doped TiO2 polyscales was carried out under mild sol–gel technique. Mg-doped TiO2 polyscales were characterized by powder XRD, SEM, FTIR, and optical and photocatalytic activity techniques. The Mg-doped TiO2 showed a mixed phase of anatase and rutile with an excellent crystallinity, structural elucidations, polyscales morphology, consequent shifting of bandgap energy and adequate photocatalytic activities under visible range of light. Mg-doped TiO2 polyscales were investigated for their efficiencies in the degradation of most commonly used industrial dyes in the real-time textile wastewater. Mg-doped TiO2 polyscales showed excellent photocatalytic degradation efficiency in both model industrial dyes (65–95%) and textile wastewater (92%) under natural sunlight as an alternative and renewable driving energy.
Keywords: Sol–gel; Photocatalyst; TiO2 polyscales; Organic dyes; Textile wastewater; Natural sunlight; Alternative driving energy

An artificial neural network (ANN) model was developed to predict the phycoremediation efficiency of Chlorella pyrenoidosa for the removal of both As(III) and As(V) from synthetic wastewater based on 49 data-sets obtained from experimental study and increased the data using CSCF technique. The data were divided into training (60%) validation (20%) and testing (20%) sets. The data collected was used for training a three-layer feed-forward back propagation (BP) learning algorithm having 4–5–1 architecture. The model used tangent sigmoid transfer function at input to hidden layer (tansing) while a linear transfer function (purelin) was used at output layer. Comparison between experimental results and model results gave a high correlation coefficient (R allANN 2 equal to 0.99987 for both ions and exhibited that the model was able to predict the phycoremediation of As(III) and As(V) from wastewater. Experimental parameters influencing phycoremediation process like pH, inoculum size, contact time and initial arsenic concentration [either As(III) or As(V)] were investigated. A contact time of 168 h was mainly required for achieving equilibrium at pH 9.0 with an inoculum size of 10% (v/v). At optimum conditions, metal ion uptake enhanced with increasing initial metal ion concentration.
Keywords: Arsenic; Wastewater; Phycoremediation; Chlorella pyrenoidosa; Artificial neural network

Using two soft computing methods to predict wall and bed shear stress in smooth rectangular channels by Zohreh Sheikh Khozani; Hossein Bonakdari; Amir Hossein Zaji (3973-3983).
Two soft computing methods were extended in order to predict the mean wall and bed shear stress in open channels. The genetic programming (GP) and Genetic Algorithm Artificial Neural Network (GAA) were investigated to determine the accuracy of these models in estimating wall and bed shear stress. The GP and GAA model results were compared in terms of testing dataset in order to find the best model. In modeling both bed and wall shear stress, the GP model performed better with RMSE of 0.0264 and 0.0185, respectively. Then both proposed models were compared with equations for rectangular open channels, trapezoidal channels and ducts. According to the results, the proposed models performed the best in predicting wall and bed shear stress in smooth rectangular channels. The obtained equation for rectangular channels could estimate values closer to experimental data, but the equations for ducts had poor, inaccurate results in predicting wall and bed shear stress. The equation presented for trapezoidal channels did not have acceptable accuracy in predicting wall and bed shear stress either.
Keywords: Shear stress; Rectangular channel; Genetic Algorithm; Artificial neural network

Water quality assessment and hydrochemical characterization of Zamzam groundwater, Saudi Arabia by Fahad N. Al-Barakah; Abdurahman M. Al-jassas; Anwar A. Aly (3985-3996).
This study focuses on chemical and microbial analyses of 50 Zamzam water samples, Saudi Arabia. The soluble ions, trace elements, total colony counts, total coliform group, and E. coli were determined and compared with WHO standards. The obtained results indicated that the dissolved salts, soluble cations and anions, Pb, Cd, As, Zn, Cu, Ni, Co, Fe, Mn, Cr, PO4 3−, NO2 , Br, F, NH4 +, and Li+, were within permissible limits for all samples. Yet, 2% of waters contain NO3 at slightly high concentration. The water quality index (WQI) reveals that 94% of the samples were excellent for drinking (class I). While the remaining was unsuitable due to total coliform group contamination “class (V)”. Durov diagram suggest no clear facies and dominant water type can be noted. It indicates mixing processes of two or more different facies might be occurring in the groundwater system. All studied waters were undersaturated with respect to halite, gypsum, fluorite, and anhydrite. These minerals tend to dissolve and increase water salinity. A direct relationship between Zamzam water salinity and rainfall is recorded. The water salinity fluctuated between 4500 mg L−1 (year 1950) and 500 mg L−1 (year 2015) based on rainfall extent. The approach applied can be used to similar groundwater worldwide.
Keywords: Zamzam; Groundwater quality; Water quality index; AquaChem software

Hydrogeochemical features of groundwater resources in Tabriz plain, northwest of Iran by Rahim Barzegar; Asghar Asghari Moghaddam; Evangelos Tziritis (3997-4011).
The present study seeks to evaluate the hydrogeochemistry of Tabriz plain in NW Iran, through major ion chemistry and their spatial variations. In order to accomplish these, groundwater sampling from 30 shallow and deep wells in the plain were carried out in July 2012. The water samples were analyzed for various physicochemical parameters such as pH, EC, Na+, Ca2+, K+, Mg2+, Cl, CO3 2−, HCO3 , SO4 2− and NO3 . Chadha’s diagram demonstrates that most of the groundwaters belonged to the Na–Cl and mixed Ca–Mg–Cl hydrochemical facies. The concentrations of some major ions in groundwater are above the permissible limit for drinking and domestic purposes except for a few locations. The results of saturation index computation show that dissolution of gypsum, anhydrite, halite and silicate minerals occurs frequently across the study area, whereas the groundwater is supersaturated with regard to calcite and dolomite. Cross-plots show that weathering and dissolution of different rocks and minerals, ion exchange, reverse ion exchange and anthropogenic activities, especially agricultural activities, are effective in hydrogeochemistry of the study area.
Keywords: Groundwater; Hydrogeochemistry; Saturation index; Tabriz plain; Iran

Geostatistical methods in evaluating spatial variability of groundwater quality in Al-Kharj Region, Saudi Arabia by Abdulrasoul M. Al-Omran; Anwar A. Aly; Mohammad I. Al-Wabel; Mohammad S. Al-Shayaa; Abdulazeam S. Sallam; Mahmoud E. Nadeem (4013-4023).
The analyses of 180 groundwater samples of Al-Kharj, Saudi Arabia, recorded that most groundwaters are unsuitable for drinking uses due to high salinity; however, they can be used for irrigation with some restriction. The electric conductivity of studied groundwater ranged between 1.05 and 10.15 dS m−1 with an average of 3.0 dS m−1. Nitrate was also found in high concentration in some groundwater. Piper diagrams revealed that the majority of water samples are magnesium–calcium/sulfate–chloride water type. The Gibbs’s diagram revealed that the chemical weathering of rock-forming minerals and evaporation are influencing the groundwater chemistry. A kriging method was used for predicting spatial distribution of salinity (EC dS m−1) and NO3 (mg L−1) in Al-Kharj’s groundwater using data of 180 different locations. After normalization of data, variogram was drawn, for selecting suitable model for fitness on experimental variogram, less residual sum of squares value was used. Then cross-validation and root mean square error were used to select the best method for interpolation. The kriging method was found suitable methods for groundwater interpolation and management using either GS+ or ArcGIS.
Keywords: Spatial variability; GS+; GIS; Hydrochemistry; Al-Kharj

In this work, we attempt a new approach for the study on photocatalytic ability of (ZnO/CeO2 ) improved by β-CD under UV light irradiation for the photodecolorization of RhB. The (ZnO/CeO2 ) composite was prepared by mixing ZnO with CeO2 in a weight ratio of 4:1. The surface interaction of (ZnO/CeO2 ) with β-CD was determined by characterizing their structural, morphological and optical properties. The formation of an inclusion complex between RhB dye and β-CD was confirmed by UV–visible spectral analyses. The photocatalytic activity of (ZnO/CeO2 )-β-CD system was evaluated by the decolorization of RhB dye in aqueous solution under UV light irradiation. The effects of operational parameters like the ratio of (ZnO/CeO2), initial concentration of dye, catalyst dose, irradiation time and pH have been analyzed. The photocatalytic decolorization of RhB follows pseudo-first order kinetics. The mineralization of RhB has been confirmed by COD measurements. A possible mechanism for the photocatalytic decolorization of RhB by (ZnO/CeO2 )-β-CD system under UV light irradiation was also discussed.
Keywords: Photocatalyst; Rhodamine B; (ZnO/CeO2)-β-CD; UV light

Totally about 174 groundwater samples have been collected during pre-monsoon and post-monsoon season to study the suitability for domestic and agriculture purposes along the coastal aquifers of Puducherry region. Parameters such as pH, total dissolved solids (TDS), electrical conductivity (EC), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), bicarbonate (HCO3), chloride (Cl) and sulfate (SO4) were analyzed to assess the suitability of groundwater for domestic purposes. Sodium adsorption ratio (SAR), magnesium adsorption ratio (MAR), residual sodium bicarbonate (RSC), soluble sodium percentage (Na%), permeability index (PI) and chlorinity index were assessed for irrigation purposes. The higher concentration of ions such as Na, Ca, Cl and So4 indicates seawater intrusion, mineral dissolution, intense agricultural practices and improper sewage disposal. The level of EC, TDS and hardness in the water samples indicates that maximum of them are suitable for drinking and domestic purposes. The parameters such as SAR, Na%, PI, MAR and Chlorinity index indicates that majority of water sample are very good to moderately suitable for agriculture. In pre-monsoon, RSC of about 5.7% of samples was higher which when used for a longer time alter the soil properties and reduce crop production. Wilcox diagram suggests that water samples are of medium saline to low sodium type indicating that groundwater is suitable for irrigation. Temporal variation of groundwater quality shows significant increasing trend in EC, TDS and ions like Mg, K and Cl in the last decade, mainly due to anthropogenic activities with little geogenic impact in the quality of groundwater.
Keywords: Groundwater; Puducherry; Domestic; Agriculture; Seawater intrusion; Wilcox

Optimal design of water distribution network is generally aimed to minimize the capital cost of the investments on tanks, pipes, pumps, and other appurtenances. Minimizing the cost of pipes is usually considered as a prime objective as its proportion in capital cost of the water distribution system project is very high. However, minimizing the capital cost of the pipeline alone may result in economical network configuration, but it may not be a promising solution in terms of resilience point of view. Resilience of the water distribution network has been considered as one of the popular surrogate measures to address ability of network to withstand failure scenarios. To improve the resiliency of the network, the pipe network optimization can be performed with two objectives, namely minimizing the capital cost as first objective and maximizing resilience measure of the configuration as secondary objective. In the present work, these two objectives are combined as single objective and optimization problem is solved by differential evolution technique. The paper illustrates the procedure for normalizing the objective functions having distinct metrics. Two of the existing resilience indices and power efficiency are considered for optimal design of water distribution network. The proposed normalized objective function is found to be efficient under weighted method of handling multi-objective water distribution design problem. The numerical results of the design indicate the importance of sizing pipe telescopically along shortest path of flow to have enhanced resiliency indices.
Keywords: Capital cost; Water distribution network; Resilience; Differential evolution

This study explores the feasibility of pre-treated coffee waste (PCW) as biosorbent for the removal of diazinon. The effect of the pesticide concentration (6–20 mg L−1), contact time, adsorbent dose (0.2–1.2 g L−1), solution pH (3–11.5), temperature (15–40 °C) and co-existing inorganic ions (H2PO4 , NO3 ) on the diazinon biosorption over PCW is investigated. The experimental results indicate an optimal pH of 7.3 for the diazinon elimination on PCW (1 g L−1). The Langmuir model describes well the isotherm data with a high regression coefficient (R 2 > 0.990) and a maximum monolayer biosorption capacity of 18.52 mg g−1 at 15 °C. It is also observed that the intra-particle diffusion is not the rate-controlling step. A comparison is evaluated between the pseudo-second-order and intra-particle diffusion kinetic models; the experimental data are well fitted by the pseudo-second-order kinetic model. The biosorption capacity decreases with increasing temperature for a diazinon concentration of 10 mg L−1. The negative enthalpy ΔH° (−63.57 kJ/mol) indicates that the diazinon biosorption onto PCW is exothermic. Under optimal conditions, the biosorption reaches 95% after 90 min. The removal efficiency decreases from 95 to 65.67 and 48.9% for the diazinon alone and in the presence of NO3 and H2PO4 (100 mg L−1), respectively.
Keywords: Biosorption; Diazinon; Pesticide; Pre-treated coffee waste

The suitability of groundwater for drinking and irrigation was assessed in Tummalapalle area. Forty groundwater samples were analysed for major cations, anions and other parameters such as pH, electrical conductivity, total dissolved solids (TDS), total alkalinity and total hardness (TH). The parameters such as sodium adsorption ratio, adjusted sodium adsorption ratio (adj.SAR), per cent sodium, potential salinity, residual sodium carbonate, non-carbonate hardness, Kelly’s ratio and permeability index were calculated for the evaluation of irrigation water quality. Groundwater chemistry was also analysed by statistical analysis, USSL, Wilcox, Doneen, Piper and Chadhas diagrams, to find out their suitability for irrigation. TDS and TH were used as main parameters to interpret the suitability of groundwater for drinking purpose. The correlation coefficient matrix between the hydrochemical parameters was carried out using Pearson’s correlation to infer the possible water–rock interactions responsible for the variation of groundwater chemistry and this has been supported by Gibbs diagram. The results indicate that the groundwater in Tummalapalle area is alkaline in nature. Ca–Mg–HCO3 is the dominant hydrogeochemical facies. Water chemistry of the study area strongly reflects the dominance of weathering of rock-forming minerals such as bicarbonates and silicates. All parameters and diagrams suggest that the water samples of the study are good for irrigation, and the plots of TDS and TH suggest that 12.5% of the samples are good for human consumption.
Keywords: Hydrogeochemistry; Water quality; Tummalapalle; Andhra Pradesh

The potentially deleterious effects of methylene blue (MB) on human health drove the interest in its removal promptly. Bioremediation is an effective and eco friendly for removing MB. Soil bacteria were isolated and examined for their potential to remove MB. The most potent bacterial candidate was characterized and identified using 16S rRNA sequence technique. The evolutionary history of the isolate was conducted by maximum likelihood method. Some physiochemical parameters were optimized for maximum decolorization. Decolorization mechanism and microbial toxicity study of MB (100 mg/l) and by-products were investigated. Participation of heat killed bacteria in color adsorption have been investigated too. The bacterial isolate was identified as Stenotrophomonas maltophilia strain Kilany_MB 16S ribosomal RNA gene with 99% sequence similarity. The sequence was submitted to NCBI (Accession number = KU533726). Phylogeny depicted the phylogenetic relationships between 16S ribosomal RNA gene, partial sequence (1442 bp), of the isolated strain and other strains related to Stenotrophomonas maltophilia in the GenBank database. The optimal conditions were investigated to be pH 5 at 30 °C, after 24 h using 5 mg/l MB showing optimum decolorization percentage (61.3%). Microbial toxicity study demonstrated relative reduction in the toxicity of MB decolorized products on test bacteria. Mechanism of color removal was proved by both biosorption and biodegradation, where heat-killed and live cells showed 43 and 52% of decolorization, respectively, as a maximum value after 24-h incubation. It was demonstrated that the mechanism of color removal is by adsorption. Therefore, good performance of S maltophilia in MB color removal reinforces the exploitation of these bacteria in environmental clean-up and restoration of the ecosystem.
Keywords: Decolorization; Methylene blue; Stenotrophomonas maltophilia

The potential use of activated carbon prepared from Ziziphus species for removing dyes from waste waters by Abdelmajid Regti; My Rachid Laamari; Salah-Eddine Stiriba; Mohammadine El Haddad (4099-4108).
In this study, the adsorption potential of activated carbon prepared from Ziziphus mauritiana nuts for the removal of methylene blue (MB) from aqueous solution has been investigated using batch mode experiments. The effects of some operating parameters on the removal dye such as, initial pH (2–12), temperature (298–328 K), initial MB concentration (20–100 mg L−1), and contact time (5–70 min) were investigated. Adsorption kinetic showed that the rate adsorption followed the pseudo-second-order kinetic model. Four adsorption isotherms models were applied to experimental equilibrium data (Langmuir, Freundlich, Redlich–Peterson, and Fritz–Schlunder) and the different constants were calculated using non-linear equations models. Fritz–Schlunder model was found the best one to describe the adsorption process which suggests that the adsorption of MB onto activated carbon derived from Ziziphus mauritiana is heterogeneous with a multilayer. Thermodynamic adsorption showed that the process was endothermic and spontaneous in nature.
Keywords: Activated carbon; Ziziphus mauritiana ; Adsorption; Removal dye; Kinetic and thermodynamic study

Water purification using porous ceramics prepared by recycling volcanic ash and waste glass by Tomohiro Ando; Yuki Fujita; Mayu Kakinaga; Nobuto Oka; Tetsuaki Nishida (4109-4115).
Water purification was examined using porous ceramics prepared by sintering a powder mixture of volcanic ash, waste glass and a small amount of wood charcoal. The porous ceramics had cross-linked 3D-channels of which the diameter ranged from several nm to several μm. Three kilograms of porous ceramics placed in 90 L of circulating artificial seawater, in which several tropical fishes were actually living under aeration, caused a decrease in COD from 23.8 to 13.1 mg L−1 in a week. The number of coliform bacteria was almost constant in a range of 52–65 mL−1 despite that a lot of excrements were discharged frequently. The number of the coliform bacteria in the seawater examined “without the tropical fishes” decreased from 900 to 1 mL−1 in 2 weeks, and COD decreased from 37.9 to 7.9 mg L−1. It proved that several aerobic bacteria proliferating in the macropores inside the porous ceramics could effectively decompose several organic materials.
Keywords: Water purification; Porous ceramics; Recycling; Volcanic ash; Waste glass; Mössbauer spectroscopy

Remote sensing and GIS play a vital role in exploration and assessment of groundwater and has wide application in detection, monitoring, assessment, conservation and various other fields of groundwater-related studies. In this research work, delineation of groundwater potential zone in Birbhum district has been carried out. Various thematic layers viz. geology, geomorphology, soil type, elevation, lineament and fault density, slope, drainage density, land use/land cover, soil texture, and rainfall are digitized and transformed into raster data in ArcGIS 10.3 environment as input factors. Thereafter, multi-influencing factor (MIF) technique is employed where ranks and weights, assigned to each factor are computed statistically. Finally, groundwater potential zones are classified into four categories namely low, medium, high and very high zone. It is observed that 18.41% (836.86 km2) and 34.41% (1563.98 km2) of the study area falls under ‘low’ and ‘medium’ groundwater potential zone, respectively. Approximately 1601.19 km2 area accounting for 35.23% of the study area falls under ‘high’ category and ‘very high’ groundwater potential zone encompasses an area of 542.98 km2 accounting for 11.95% of the total study area. Finally, the model generated groundwater potential zones are validated with reported potential yield data of various wells in the study area. Success and prediction rate curve reveals an accuracy achievement of 83.03 and 78%, respectively. The outcome of the present research work will help the local authorities, researchers, decision makers and planners in formulating better planning and management of groundwater resources in the study area in future perspectives.
Keywords: Remote sensing and GIS; Multi-influencing factor (MIF) technique; Groundwater potential zone; Birbhum; West Bengal; India

The present study includes a systematic analysis of sediment contamination by heavy metals of the River Ghaghara flowing through the Uttar Pradesh and Bihar in Indian Territory. To estimate the geochemical environment of the river, seven heavy metals, namely Co, Cu, Cr, Ni, Cd, Zn, and Pb were examined from the freshly deposited river bed sediment. All the sediment samples were collected on a seasonal basis for the assessment of fluctuation in 2014–2015 and after preparation samples were analyzed using standard procedure. Result showed that heavy metal concentration ranged between 11.37 and 18.42 mg/kg for Co, 2.76 and 11.74 mg/kg for Cu, 61.25 and 87.68 mg/kg for Cr, 15.29 and 25.59 mg/kg for Ni, 0.21 and 0.28 mg/kg for Cd, 13.26 and 17.59 mg/kg for Zn, 10.71 and 14.26 mg/kg for Pb in different season. Metal contamination factor indicates the anthropogenic input in the river sediment was in the range of (0.62–0.97) for Co, (0.04–0.26) for Cu, (0.68–0.97) for Cr, (0.22–0.38) for Ni, (0.70–0.93) for Cd, (0.14–0.19) for Zn, and (0.54–0.71) for Pb. The highest contamination degree of the sediment was noticed as 4.01 at Ayodhya and lowest as 3.16 at Katerniaghat. Geo-accumulation index was noted between (0 and 1) which showed that sediment was uncontaminated to moderately contaminated and may have adverse affects on freshwater ecology of the river. Pollution load index (PLI) was found highest at Chhapra which was 0.45 and lowest at Katerniaghat which was 0.35 and it indicates that the river sediment has a low level of contamination. Significant high correlation was observed between Co, Cu, and Zn, it suggests same source of contamination input is mainly due to human settlement and agriculture activity. Positive correlation between Zn, Co, Cu, Cr, and Ni indicated a natural origin of these elements in the river sediment. Cluster analysis suggests grouping of similar polluted sites. The strong similarity between Co, Zn, Pb, Ni, Cu, and Cd showed relationship of these metals come from the same origin, which is possibly from natural and anthropogenic input which was also confirmed by correlation analysis. Using the various pollution indicators it was found that the river bed sediment is less contaminated by toxic metals during the study but the sediment quality may degrade in the near future due to increasing anthropogenic inputs in the river basin, hence proper management strategies are required to control the direct dumping of wastewater in the river.
Keywords: Sediment contamination; Heavy metals; Geo-accumulation index; Contamination factor; Pollution load index; Aquatic ecosystem

Wastewater treatment by local microalgae strains for CO2 sequestration and biofuel production by Abeera A. Ansari; Asif Hussain Khoja; Azra Nawar; Muneeb Qayyum; Ehsan Ali (4151-4158).
Currently, the scientific community is keenly working on environmental-friendly processes for the production of clean energy and sustainable development. The study was conducted to cultivate microalgae in raw institutional wastewater for water treatment, enriched production of biomass and CO2 sequestration. The strains which were used in this study are Scenedesmus sp. and Chlorella sp. which were isolated from Kallar Kahar Lake, Pakistan. Both strains were cultivated in synthetic growth medium (Bold’s Basal Medium) to enhance biomass production. Afterward, microalgae cultures were inoculated in wastewater sample in mixotrophic mode under ambient conditions. The impurities in wastewater were successfully removed from the original sample by the 7th day of operation. COD 95%, nitrate 99.7% and phosphate 80.5% were removed by applying Scenedesmus sp. Meanwhile, Chlorella sp. reduced 84.86% COD, 98.2% nitrate and 70% phosphate, respectively. Interestingly, sulfates were removed from wastewater completely by both strains. Besides being useful in wastewater remediation, these microalgae strains were subsequently harvested for lipid extraction and potential biofuel production was determined. Therefore, the applied method is an environmentally safe, cost-effective and alternative technology for wastewater treatment. Furthermore, the achieved biomass through this process can be used for the production of biofuels.
Keywords: Wastewater treatment; Microalgae; COD; Nutrients; Biofuel

We report here the synthesis of CuO-doped ZnO composite nanomaterials (NMs) by chemical route and demonstrated for the first time that these NMs are efficient catalysts for H2O2-assisted photo-decomposition (photo-Fenton type catalyst) of humic acid, a natural pollutant of surface water by solar irradiation. This has been explained by faster electron transfer to OH radical at the p–n hetero-junction of this composite catalyst. Application of this composite catalyst in decomposing humus substances of local pond water by solar energy has been demonstrated.
Keywords: Photo-Fenton reaction; Humic acid; CuO-doped ZnO composite nanomaterials

The need and demand for water in the world are becoming acute with the growing population. This is mostly pressing in developing countries of which Mekelle City in Northern Ethiopia is not an exception. World Bank borehole-support sub-project was aimed at addressing this challenge. The evaluation of the intervention indicates that there is a significant increase in water supply in the city because of the sub-project. However, the increase in water supply has not been able to meet up with the already established and increasing demand. Coupled with this challenge are: the limited capacity of human capital and expertise that will ensure the proper management of borehole interventions; insufficient cost recovery for proper operation and maintenance of the projects; loss of land and farmlands and lack of compensations because of the projects which affect the livelihood.
Keywords: Water project; Water demand; Cost recovery; World Bank intervention