Applied Water Science (v.7, #8)

3D-modelling of the thermal circumstances of a lake under artificial aeration by Xiaoqing Tian; Huachen Pan; Petrina Köngäs; Jukka Horppila (4169-4176).
A 3D-model was developed to study the effects of hypolimnetic aeration on the temperature profile of a thermally stratified Lake Vesijärvi (southern Finland). Aeration was conducted by pumping epilimnetic water through the thermocline to the hypolimnion without breaking the thermal stratification. The model used time transient equation based on Navier–Stokes equation. The model was fitted to the vertical temperature distribution and environmental parameters (wind, air temperature, and solar radiation) before the onset of aeration, and the model was used to predict the vertical temperature distribution 3 and 15 days after the onset of aeration (1 August and 22 August). The difference between the modelled and observed temperature was on average 0.6 °C. The average percentage model error was 4.0% on 1 August and 3.7% on 22 August. In the epilimnion, model accuracy depended on the difference between the observed temperature and boundary conditions. In the hypolimnion, the model residual decreased with increasing depth. On 1 August, the model predicted a homogenous temperature profile in the hypolimnion, while the observed temperature decreased moderately from the thermocline to the bottom. This was because the effect of sediment was not included in the model. On 22 August, the modelled and observed temperatures near the bottom were identical demonstrating that the heat transfer by the aerator masked the effect of sediment and that exclusion of sediment heat from the model does not cause considerable error unless very short-term effects of aeration are studied. In all, the model successfully described the effects of the aerator on the lake’s temperature profile. The results confirmed the validity of the applied computational fluid dynamic in artificial aeration; based on the simulated results, the effect of aeration can be predicted.
Keywords: Hypolimnetic aeration; Water temperature; 3D-modelling

Metallic iron for water treatment: leaving the valley of confusion by Susanne Makota; Arnaud I. Nde-Tchoupe; Hezron T. Mwakabona; Raoul Tepong-Tsindé; Chicgoua Noubactep; Achille Nassi; Karoli N. Njau (4177-4196).
Researchers on metallic iron (Fe0) for environmental remediation and water treatment are walking in a valley of confusion for 25 years. This valley is characterized by the propagation of different beliefs that have resulted from a partial analysis of the Fe0/H2O system as (1) a reductive chemical reaction was considered an electrochemical one and (2) the mass balance of iron has not been really addressed. The partial analysis in turn has been undermining the scientific method while discouraging any real critical argumentation. This communication re-establishes the complex nature of the Fe0/H2O system while recalling that, finally, proper system analysis and chemical thermodynamics are the most confident ways to solve any conflicting situation in Fe0 environmental remediation.
Keywords: Mainstream science; Valley of confusion; Water treatment; Zero-valent iron

The assessment of surface water in Koudiat Medouar watershed is very important especially when it comes to pollution of the dam waters by discharges of wastewater from neighboring towns in Oued Timgad, who poured into the basin of the dam, and agricultural lands located along the Oued Reboa. To this end, the multivariable method was used to evaluate the spatial and temporal variation of the water surface quality of the Koudiat Medouar dam, eastern Algeria. The stiff diagram has identified two main hydrochemical facies. The first facies Mg-HCO3 is reflected in the first sampling station (Oued Reboa) and in the second one (Oued Timgad), while the second facies Mg-SO4 is reflected in the third station (Basin Dam). The results obtained by the analysis of variance show that in the three stations all parameters are significant, except for Na, K and HCO3 in the first station (Oued Reboa) and the EC in the second station (Oued Timgad) and at the end NO3 and pH in the third station (Basin Dam). Q-mode hierarchical cluster analysis showed that two main groups in each sampling station. The chemistry of major ions (Mg, Ca, HCO3 and SO4) within the three stations results from anthropogenic impacts and water–rock interaction sources.
Keywords: Surface water; Hierarchical cluster analysis; Analysis of variance; Koudiat Medouar watershed

Contemplating the feasibility of vermiculate blended chitosan for heavy metal removal from simulated industrial wastewater by N. Prakash; M. Soundarrajan; S. Arungalai Vendan; P. N. Sudha; N. G. Renganathan (4207-4218).
Wastewater contaminated by heavy metals pose great challenges as they are non biodegradable, toxic and carcinogenic to the soil and aquifers. Vermiculite blended with chitosan have been used to remove Cr(VI) and Cd(II) from the industrial wastewater. The results indicate that the vermiculite blended with chitosan adsorb Cr(VI) and Cd(II) from industrial waste water. Batch adsorption experiments were performed as a function of pH 5.0 and 5.5 respectively for chromium and cadmium. The adsorption rate was observed to be 72 and 71 % of chromium and cadmium respectively. The initial optimum contact time for Cr(VI) was 300 min with 59.2 % adsorption and 300 min for Cd(II) with 71.5 % adsorption. Whereas, at 4–6 there is saturation, increasing the solid to liquid ratio for chitosan biopolymers increases the number of active sites available for adsorption. The optimum pH required for maximum adsorption was found to be 5.0 and 5.5 for chromium and cadmium respectively. The experimental equilibrium adsorption data were fitted using Langmuir and Freundlich equations. It was observed that adsorption kinetics of both the metal ions on vermiculite blended chitosan is well be analyzed with pseudo-second-order model. The negative free energy change of adsorption indicates that the process was spontaneous and vermiculite blended chitosan was a favourable adsorbent for both the metals.
Keywords: Chromium(VI); Cadmium(II); Chitosan mixed vermiculite; Adsorption isotherms; Kinetics

Hydrogeochemical investigation of groundwater in shallow coastal aquifer of Khulna District, Bangladesh by S. M. Didar-Ul Islam; Mohammad Amir Hossain Bhuiyan; Tanjena Rume; Gausul Azam (4219-4236).
Groundwater acts as a lifeline in the coastal regions to meet out the domestic, drinking, irrigational and industrial needs. To investigate the hydrogeochemical characteristics of groundwater and its suitability, twenty samples were collected from the shallow tubewells of study area having screen depth 21–54 m. The water quality assessment has been carried out by evaluating the physicochemical parameters such as temperature, pH, EC, TDS and major ions i.e., Na+, K+, Ca2+, Mg2+, Cl, SO4 2−, NO3 , HCO3 . Results found that, the water is slightly alkaline and brackish in nature. The trends of cations and anions are Na+ > Ca2+ > Mg2+ > K+ and Cl > HCO3  > SO4 2− > NO3 , respectively and Na–Cl–HCO3 is the dominant groundwater type. The analyzed samples were also characterized with different indices, diagram and permissible limit i.e., electric conductivity (EC), total dissolved solids (TDS), chloride content (Cl), soluble sodium percentage (SSP), sodium adsorption ratio (SAR), residual sodium carbonate (RSC), magnesium adsorption ratio (MAR), Kelley’s ratio (KR), Wilcox diagram and USSL diagram, and results showed that groundwater are not suitable for drinking and irrigational use. The factors responsible for the geochemical characterization were also attempted by using standard plot and it was found that mixing of seawater with entrapped water plays a significant role in the study area.
Keywords: Groundwater quality; Electric conductivity; Salinity intrusion; Hydrogeochemical processes; Coastal region

Decolorization of brilliant green dye using immersed lamp sonophotocatalytic reactor by Vitthal L. Gole; Astha Priya; Sanjay P. Danao (4237-4245).
The textile and dye industries require an enormous amount of water for processing and produce a large volume of wastewater. Generated wastewater had potential hazards and a threat to the aquatic biota. The present work investigates the decolorization of brilliant green dye using a combination of two advanced oxidation techniques viz sonocatalysis and photocatalysis (immersed lamp) known as sonophotocatalysis (3 L capacity). The efficiency of decolorization is further improved in the presence of various additives viz. copper oxide, zinc oxide, and sodium chloride. The maximum decolorization of brilliant green (BG) (94.8% in 120 min) obtained in the presence of zinc oxide. The total organic carbon of the treated samples was measured to monitor complete mineralization of BG. The sonophotocatalytic process (in the presence of zinc oxide) shows maximum mineralization. Synergic combination of two oxidation processes increased the production of oxidizing radicals. Continuous cleaning of catalyst surface (due to sonolysis effect) improves the activity of the catalyst for photolysis operation. The present work is highly useful for the development of a sonophotocatalytic process.
Keywords: Sonophotocatalysis; Brilliant green dye; Decolorization; Sonocatalysis; Photocatalysis

Modification of activated carbon via grafting polyethyleneimine to remove amaranth from water by Likang Fu; Gengwei Zhang; Shixing Wang; Libo Zhang; Jinhui Peng (4247-4254).
A new adsorbent was fabricated via grafting polyethyleneimine (PEI) on activated carbon (AC) to remove anionic amaranth from water. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were used to characterize the grafting process of PEI. The adsorption behavior of the anionic amaranth (AM) on the modified AC is further evaluated by adjusting pH, the modified AC dosage, contact time and the initial AM concentration. AM adsorption was dramatically dependent of solution pH and the optimum pH is 1.08. The adsorption rate was very high within 20 min and equilibrium was achieved at 180 min. The maximum adsorption amount of AM on the modified AC is 72.68 mg/g at pH 1.08. Compared with the unmodified AC, the adsorption efficiency on the modified AC was dramatically increased from 29.9 to 97%. An electrostatic interaction mechanism was proposed in the acidic solution. The adsorption isotherms were consistent with the Langmuir model and the obtained kinetic data were in accordance with a pseudo-second order adsorption behavior for the modified AC.
Keywords: Activated carbon; Modify; Adsorption; Dyes; Mechanism

The removal of Rhodamine B, Eriochrome black T and Murexide dyes from aqueous solutions using calcined eggshell powder were investigated. In this study, calcined eggshell powder was applied for its potential use as an adsorbent for the removal of Rhodamine B, Eriochrome black T and Murexide dyes from their aqueous solutions. The calcined eggshell powder obtained was characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). The various parameters such as initial concentration, pH, adsorbent dose and contact time were studied. Various isotherms including Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models were applied for the equilibrium adsorption data. The kinetic study of Rhodamine B, Eriochrome black T and Murexide dyes on calcined eggshell powder follows pseudo-second order kinetics.
Keywords: Eggshell; Removal; Dyes; Langmuir; Freundlich

In this study Fenton’s oxidation of dicamba in aqueous medium was investigated by using the response surface methodology. The influence of H2O2/COD (A), H2O2/Fe2+ (B), pH (C) and reaction time (D) as independent variables were studied on two responses (COD and dicamba removal efficiency). The dosage of H2O2 (5.35–17.4 mM) and Fe2+ (0.09–2.13 mM) were varied and optimum percentage removal of dicamba of 84.01% with H2O2 and Fe2+ dosage of 11.38 and 0.33 mM respectively. The whole oxidation process was monitored by high performance liquid chromatography (HPLC) along with liquid chromatography/mass spectrometry (LC/MS). It was found that 82% of dicamba was mineralized to oxalic acid, chloride ion, CO2 and H2O, which was confirmed with COD removal of 81.53%. The regression analysis was performed, in which standard deviation (<4%), coefficient of variation (<8), F value (Fisher’s Test) (>2.74), coefficient of correlation (R 2 = $$R_{ ext{adj}}^{2}$$ R adj 2 ) and adequate precision (>12) were in good agreement with model values. Finally, the treatment process was validated by performing the additional experiments.
Keywords: Dicamba; Fenton’s process; Response surface methodology; Herbicide; Agriculture runoff

Waste water purification using new porous ceramics prepared by recycling waste glass and bamboo charcoal by Tetsuaki Nishida; Akane Morimoto; Yoshito Yamamoto; Shiro Kubuki (4281-4286).
New porous ceramics (PC) prepared by recycling waste glass bottle of soft drinks (80 mass%) and bamboo charcoal (20 mass%) without any binder was applied to the waste water purification under aeration at 25 °C. Artificial waste water (15 L) containing 10 mL of milk was examined by combining 15 mL of activated sludge and 750 g of PC. Biochemical oxygen demand (BOD) showed a marked decrease from 178 to 4.0 (±0.1) mg L−1 in 5 days and to 2.0 (±0.1) mg L−1 in 7 days, which was equal to the Environmental Standard for the river water (class A) in Japan. Similarly, chemical oxygen demand (COD) decreased from 158 to 3.6 (±0.1) mg L−1 in 5 days and to 2.2 (±0.1) mg L−1 in 9 days, which was less than the Environmental Standard for the Seawater (class B) in Japan: 3.0 mg L−1. These results prove the high water purification ability of the PC, which will be effectively utilized for the purification of drinking water, fish preserve water, fish farm water, etc.
Keywords: Water purification; Porous ceramics; Recycling; Waste glass; Bamboo charcoal

Since the flow entering a sewer contains solid matter, deposition at the bottom of the channel is inevitable. It is difficult to understand the complex, three-dimensional mechanism of sediment transport in sewer pipelines. Therefore, a method to estimate the limiting velocity is necessary for optimal designs. Due to the inability of gradient-based algorithms to train Adaptive Neuro-Fuzzy Inference Systems (ANFIS) for non-deposition sediment transport prediction, a new hybrid ANFIS method based on a differential evolutionary algorithm (ANFIS-DE) is developed. The training and testing performance of ANFIS-DE is evaluated using a wide range of dimensionless parameters gathered from the literature. The input combination used to estimate the densimetric Froude number (Fr) parameters includes the volumetric sediment concentration (C V ), ratio of median particle diameter to hydraulic radius (d/R), ratio of median particle diameter to pipe diameter (d/D) and overall friction factor of sediment (λ s ). The testing results are compared with the ANFIS model and regression-based equation results. The ANFIS-DE technique predicted sediment transport at limit of deposition with lower root mean square error (RMSE = 0.323) and mean absolute percentage of error (MAPE = 0.065) and higher accuracy (R 2 = 0.965) than the ANFIS model and regression-based equations.
Keywords: ANFIS; Bed load; Differential Evolution (DE); Non-deposition; Pipe; Sediment transport

In this study, low-cost activated carbon (AC) prepared from baobab fruit shells by chemical activation using phosphoric acid was evaluated for the removal of Cu(II) ions from aqueous solution. The prepared activated carbon samples were characterized using N2-adsorption–desorption isotherms, SEM, FTIR, EDX and XRD analysis. The sample activated at 700 °C was chosen as our optimized sample because its physicochemical properties and BET results were similar to those of a commercial sample. The N2-adsorption–desorption results of the optimized sample revealed a BET surface area of 1089 m2/g, micropore volume of 0.3764 cm3/g, total pore volume of 0.4330 cm3/g and pore size of 1.45 nm. Operational parameters such as pH, initial copper concentration, contact time, adsorbent dosage and temperature were studied in a batch mode. Equilibrium data were obtained by testing the adsorption data using three different isotherm models: Langmuir, Freundlich and Dubinin–Radushkevish (D–R) models. It was found that the adsorption of copper correlated well with the Langmuir isotherm model with a maximum monolayer adsorption capacity of 3.0833 mg/g. The kinetics of the adsorption process was tested through pseudo-first-order and pseudo-second-order models. The pseudo-second-order kinetic model provided the best correlation for the experimental data studied. The adsorption followed chemisorption process. The study provided an effective use of baobab fruit shells as a valuable source of adsorbents for the removal of copper ions from aqueous solution. This study could add economic value to baobab fruit shells in Malawi, reduce disposal problems, and offer an economic source of AC to the AC users.
Keywords: Cu(II) ions; Baobab fruit shell; Activated carbon; Adsorption isotherm and kinetics

Comparative study of Wenner and Schlumberger electrical resistivity method for groundwater investigation: a case study from Dhule district (M.S.), India by Baride Mukund Vasantrao; Patil Jitendra Bhaskarrao; Baride Aarti Mukund; Golekar Rushikesh Baburao; Patil Sanjaykumar Narayan (4321-4340).
The area chosen for the present study is Dhule district, which belongs to the drought prone area of Maharashtra State, India. Dhule district suffers from water problem, and therefore, there is no extra water available to supply for the agricultural and industrial growth. To understand the lithological characters in terms of its hydro-geological conditions, it is necessary to understand the geology of the area. It is now established fact that the geophysical method gives a better information of subsurface geology. Geophysical electrical surveys with four electrodes configuration, i.e., Wenner and Schlumberger method, were carried out at the same selected sites to observe the similarity and compared both the applications in terms of its use and handling in the field. A total 54 VES soundings were carried out spread over the Dhule district and representing different lithological units. The VES curves are drawn using inverse slope method for Wenner configuration, IPI2 win Software, and curve matching techniques were used for Schlumberger configuration. Regionwise lithologs are prepared based on the obtained resistivity and thickness for Wenner method. Regionwise curves were prepared based on resistivity layers for Schlumberger method. Comparing the two methods, it is observed that Wenner and Schlumberger methods have merits or demerits. Considering merits and demerits from the field point of view, it is suggested that Wenner inverse slope method is more handy for calculation and interpretation, but requires lateral length which is a constrain. Similarly, Schlumberger method is easy in application but unwieldy for their interpretation. The work amply proves the applicability of geophysical techniques in the water resource evaluation procedure. This technique is found to be suitable for the areas with similar geological setup elsewhere.
Keywords: Geophysics; Groundwater; Exploration; Vertical electrical sounding; Wenner and Schlumberger

Modification of thin-film polyamide membrane with multi-walled carbon nanotubes by interfacial polymerization by Abdullah S. Al-Hobaib; Kh. M. Al-Sheetan; Mohammed Rafi Shaik; M. S. Al-Suhybani (4341-4350).
Polyamide thin-film composite (TFC) was fabricated on polysulfone (PS-20) base by interfacial polymerization of aqueous m-phenylenediamine (MPD) solution and 1,3,5-benzenetricarbonyl trichloride (TMC) in hexane organic solution. Multi-wall carbon nanotubes (MWCNT) were carboxylated by heating MWCNT powder in a mixture of HNO3 and H2SO4 (1:3 v/v) at 70 °C under constant sonication for different periods. Polyamide nanocomposites were prepared by incorporating MWCNT and the carboxylated MWCNT (MWCNT–COOH) at different concentrations (0.001–0.009 wt%). The developed composites were analyzed by Fourier transform infrared spectroscopy-attenuated total reflection, scanning electron microscopy, transmission electron microscopy, contact angle measurement, determination of salt rejection and water permeate flux capabilities. The surface morphological studies displayed that the amalgamation of MWCNT considerably changed the surface properties of modified membranes. The surface hydrophilicity was increased as observed in the enhancement in water flux and pure water permeance, due to the presence of hydrophilic nanotubes. Salt rejection was obtained between 94 and 99% and varied water flux values for TFC-reference membrane, pristine-MWCNT in MPD, pristine-MWCNT in TMC and MWCNT–COOH in MPD were 20.5, 38, 40 and 43 L/m2h. The water flux and salt rejection performances revealed that the MWCNT–COOH membrane was superior membrane as compared to the other prepared membranes.
Keywords: Polymerization; Phenylenediamine; Membrane; Carbon nanotube; Desalination

Functionalized dithiocarbamate chelating resin for the removal of Co2+ from simulated wastewater by Xuewei Shi; Linwei Fu; Yanyang Wu; Huiling Zhao; Shuangliang Zhao; Shouhong Xu (4351-4360).
Industrial wastewater that contains trace amounts of heavy metal ions is often seen in petrochemical industry. While this wastewater can not be directly discharged, it is difficult to treat due to the low concentration of metal ions. Introducing chelating reagents into this wastewater for selective ion adsorption, followed by a mechanical separation process, provides an appealing solution. Toward the success of this technology, the development of effective chelating resins is of key importance. In the present work, a chelating resin containing amino and dithiocarbamate groups was reported for the removal of Co(II) metal ions in trace concentrations from simulated wastewater. By investigating the adsorption performance of the chelating resin at different solution pH values, adsorbent dosages, contact time, initial ion concentrations, and adsorption temperatures, the maximum adsorption capacity of the resin for Co(II) was identified to be 24.89 mg g−1 for a 2 g L−1 adsorbent dosage and a pH value of 5. After four adsorption–desorption cycles, 97% of the adsorption capacity of the resin was maintained. The adsorption kinetics and thermodynamics were analyzed and discussed as well.
Keywords: DTC resin; Co(II) removal; Adsorption kinetics; Wastewater

In this study, simultaneous removal of Cr(VI) and phenol from binary solution was carried out using Fe-treated tea waste biomass. The effect of process parameters such as adsorbent dose, pH, initial concentration of Cr(VI) (mg/L), and initial concentration of phenol (mg/L) was optimized. The analysis of variance of the quadratic model demonstrates that the experimental results are in good agreement with the predicted values. Based on experimental design at an initial concentration of 55 mg/L of Cr(VI), 27.50 mg/L of phenol, pH 2.0, 15 g/L adsorbent dose, 99.99% removal of Cr(VI), and phenol was achieved.
Keywords: Binary solution; Cr(VI); Phenol; Response surface methodology; Fe-treated tea waste biomass

Assessment of On-site sanitation system on local groundwater regime in an alluvial aquifer by Rafat Quamar; C. Jangam; J. Veligeti; P. Chintalapudi; R. Janipella (4375-4386).
The present study is an attempt to study the impact of the On-site sanitation system on the groundwater sources in its vicinity. The study has been undertaken in the Agra city of Yamuna sub-basin. In this context, sampling sites (3 nos) namely Pandav Nagar, Ayodhya Kunj and Laxmi Nagar were selected for sampling. The groundwater samples were analyzed for major cations, anions and faecal coliform. Critical parameters namely chloride, nitrate and Faecal coliform were considered to assess the impact of the On-site sanitation systems. The analytical results shown that except for chloride, most of the samples exceeded the Bureau of Indian Standard limits for drinking water for all the other analyzed parameters, i.e., nitrate and faecal coliform in the first two sites. In Laxmi Nagar, except for faecal coliform, all the samples are below the BIS limits. In all the three sites, faecal coliform was found in majority of the samples. A comparison of present study indicates that the contamination of groundwater in alluvial setting is less as compared to hard rock where On-site sanitation systems have been implemented.
Keywords: On-site sanitation; Seasonal variation; Groundwater; Nitrate; Faecal coliform

Effect of bore fluid flow rate on formation and properties of hollow fibers by Asrar A. Alobaidy; Bashir Y. Sherhan; Areej D. Barood; Qusay F. Alsalhy (4387-4398).
In this work, for high performance and wide range of ultrafiltration applications, the effects of the most widely used values of internal coagulant flow rates (ICFR) (i.e., 2.6, 3.6, 4, 5, 7, 9, 11, and 13 ml/min) on the different features of the polyvinylchloride hollow fiber have been investigated. Both the idealized straight and the cylindrical pore with small effect of tortuosity were approximately obtained through the effect of ICFR. Atomic force microscope (AFM), scanning electron microscope (SEM), and ultrafiltration measurements were utilized to characterize the hollow fibers. The SEM and AFM results indicated that the cross-sectional morphology of the fibers is changed significantly with various ICFR. The structure of the inner surface was also changed from an open cellular structure to a porous structure by means of high pore density and small pore diameter. In addition, the membrane thickness was reduced by 314% with an increase in the ICFR from 2.6 to 13 ml/min. The pure water permeation flux was improved 17 times when ICFR was increased to 13 ml/min, while the BSA rejection remained within the acceptable range (from 93.4 to 90.4) when the ICFR was increased from 2.6 to 9 ml/min.
Keywords: Hollow fiber; Ultrafiltration; PVC; Internal coagulant; Separation performance

The quantitative analysis of drainage system is an important aspect of characterization of watersheds. Using watershed as a basin unit in morphometric analysis is the most logical choice because all hydrological and geomorphic processes occur within the watershed. The Budigere Amanikere watershed a tributary of Dakshina Pinakini River has been selected for case illustration. Geoinformatics module consisting of ArcGIS 10.3v and Cartosat-1 Digital Elevation Model (DEM) version 1 of resolution 1 arc Sec (~32 m) data obtained from Bhuvan is effectively used. Sheet and gully erosion are identified in parts of the study area. Slope in the watershed indicating moderate to least runoff and negligible soil loss condition. Third and fourth-order sub-watershed analysis is carried out. Mean bifurcation ratio (R b) 3.6 specify there is no dominant influence of geology and structures, low drainage density (D d) 1.12 and low stream frequency (F s) 1.17 implies highly infiltration subsoil material and low runoff, infiltration number (I f)1.3 implies higher infiltration capacity, coarse drainage texture (T) 3.40 shows high permeable subsoil, length of overland flow (L g) 0.45 indicates under very less structural disturbances, less runoff conditions, constant of channel maintenance (C) 0.9 indicates higher permeability of subsoil, elongation ratio (R e) 0.58, circularity ratio (R c) 0.75 and form factor (R f) 0.26 signifies sub-circular to more elongated basin with high infiltration with low runoff. It was observed from the hypsometric curves and hypsometric integral values of the watershed along with their sub basins that the drainage system is attaining a mature stage of geomorphic development. Additionally, Hypsometric curve and hypsometric integral value proves that the infiltration capacity is high as well as runoff is low in the watershed. Thus, these mormometric analyses can be used as an estimator of erosion status of watersheds leading to prioritization for taking up soil and water conservation measures.
Keywords: Morphometry; Cartosat-1DEM; Budigere Amanikere watershed; Dakshina Pinakini; Hypsometric curve and hypsometric integral and RS and GIS

An empirical model is proposed to predict the velocity dip position at the central section of open channels. The model is fitted based on asymptotic matching technique and validated by using a wide range of aspect ratios (channel width/flow depth) from 0.155 to 15. The matching approach, which relies on dividing the trend into smaller segments that can be combined into an overall relation, employs regression technique and thus warrants the best-fit accuracy results. The obtained model satisfies the upper and lower bounds of dip positions equal to 0.5 and 1, respectively. A comparison with other formulas widely reported in the literature is provided. The model is also applied to predict Reynolds shear stress and velocity distribution in open channels. This model will help extending our ability for analyzing velocity field in open channels under different flow and boundary conditions.
Keywords: Velocity distribution; Secondary current; Asymptotic matching; Aspect ratio; Sidewall effect

Characterization and evaluation of amorphous carbon thin film (ACTF) for sodium ion adsorption by Mahmoud Fathy; Mahmoud Ahmed Mousa; Th. Abdel Moghny; Ahmed E. Awadallah (4427-4435).
The removal of sodium ions from aqueous solutions by adsorption onto amorphous carbon thin film (ACTF) has been studied in batch mode. In this work, the ACTF as new adsorbent was synthesized based on rice straw, then its structure and properties were taken into consideration to study its ability to adsorb sodium ions from synthetic water. The influence of pH, contact time, and temperature of the ion adsorption on ACTF was also studied using batch tests. We found that the contact time of sodium adsorption and its isothermal adsorption studied were described by pseudo-second-order kinetic model and Langmuir isotherm, respectively. Our results indicated that the adsorption of sodium ions on ACTF become be stronger and depends on pH, furthermore, the maximum adsorption capacities of sodium on ACTF recorded 107, 120 and 135 mg g−1 at 35, 45, and 65 °C. The thermodynamic parameters explain that the adsorption of sodium ions on ACTF is a spontaneous process and endothermic reaction. According to adsorption studies, we found that the ACTF can be used effectively for ion chromatography or desalinate sodium ion using ion exchange process in the hybrid desalination process with insignificant loss of adsorption capacity. However, the ACTF has better properties than any other carbon materials obtained from an agricultural byproduct.
Keywords: Capacity; Carbon; Adsorption; Amorphous; Cellulose; Hybrid desalination

Performance evaluation of household water treatment systems used in Kerman for removal of cations and anions from drinking water by Mohammad Malakootian; Najmeh Amirmahani; Ghazal Yazdanpanah; Alireza Nasiri; Ali Asadipour; Ahmad Ebrahimi; Sodaif Darvish Moghaddam (4437-4447).
Increased awareness in society of the consequences of contaminants in drinking water has created a demand for household water treatment systems, which provide higher quality water, to spread. The aim of this study was to evaluate the performance of household water treatment systems used in Kerman for the removal of cations and anions. Various brands of home water treatment devices commonly used in Kerman were selected, with one device chosen from each brand for study. In cases in which the devices were used extensively, samples were selected with filters that had been changed in proper time, based on the device’s operational instructions. The samples were selected from homes in the center and four geographical directions of Kerman. Then, sampling was conducted in three stages of input and output water of each device. For each of the samples, parameters were measured, such as chloride, sulfate, bicarbonate, calcium, magnesium, hardness, sodium, nitrate and nitrite (mg/L), temperature (°C), and pH. The average removal efficiency of different parameters by 14 brands in Kerman, which include chloride ions, sulfate, bicarbonate, calcium, magnesium, sodium, nitrites, nitrates, and total hardness, was obtained at 68.48, 85, 67, 61.21, 78.97, 80.24, 32.59, 66.83, and 69.38%, respectively. The amount of sulfate, bicarbonate, chloride, calcium, magnesium, hardness, sodium, and nitrate in the output water of household water treatment systems was less than the input water of these devices, but nitrite concentration in the output of some devices was more than the input water and showed a significant difference (p > 0.05).
Keywords: Performance evaluation; Chemical quality; Kerman water; Household water treatment systems

Co-precipitation procedure has widely been employed for preconcentration and separation of metal ions from the matrices of environmental samples. This is simply due to its simplicity, low consumption of separating solvent and short duration for analysis. Various organic ligands have been used for this purpose. However, there is dearth of information on the application of 8-hydroxyquinoline (8-HQ) as ligand and Cu(II) as carrier element. The use of Cu(II) is desirable because there is no contamination and background adsorption interference. Therefore, the objective of this study was to use 8-HQ in the presence of Cu(II) for coprecipitation of Cd(II), Co(II), Cr(III), Ni(II) and Pb(II) from standard solutions and surface water prior to their determinations by flame atomic absorption spectrometry (FAAS). The effects of pH, sample volume, amount of 8-HQ and Cu(II) and interfering ions on the recoveries of metal ions from standard solutions were monitored using FAAS. The water samples were treated with 8-HQ under the optimum experimental conditions and metal concentrations were determined by FAAS. The metal concentrations in water samples not treated with 8-HQ were also determined. The optimum recovery values for metal ions were higher than 85.0%. The concentrations (mg/L) of Co(II), Ni(II), Cr(III), and Pb(II) in water samples treated with 8-HQ were 0.014 ± 0.002, 0.03 ± 0.01, 0.04 ± 0.02 and 0.05 ± 0.02, respectively. These concentrations and those obtained without coprecipitation technique were significantly different. Coprecipitation procedure using 8-HQ as ligand and Cu(II) as carrier element enhanced the preconcentration and separation of metal ions from the matrix of water sample.
Keywords: Co-precipitation; 8-hydroxyquinoline; Surface water; Heavy metals; Atomic absorption spectrometry

An economic assessment of local farm multi-purpose surface water retention systems in a Canadian Prairie setting by Pamela Berry; Fuad Yassin; Kenneth Belcher; Karl-Erich Lindenschmidt (4461-4478).
There is a need to explore more sustainable approaches to water management on the Canadian Prairies. Retention pond installation schemes designed to capture surface water may be a viable option that would reduce water stress during drought periods by providing water for irrigation. The retention systems would serve to capture excess spring runoff and extreme rainfall events, reducing flood potential downstream. Additionally, retention ponds may be used for biomass production and nutrient retention. The purpose of this research was to investigate the economic viability of adopting local farm surface water retention systems as a strategic water management strategy. A retention pond was analyzed using a dynamic simulation model to predict its storage capacity, installation and upkeep cost, and economic advantage to farmers when used for irrigation. While irrigation application increased crop revenue, the cost of irrigation and reservoir infrastructure and installation costs were too high for the farmer to experience a positive net revenue. Farmers who harvest cattails from retention systems for biomass and available carbon offset credits can gain $642.70/hectare of harvestable cattail/year. Cattail harvest also removes phosphorus and nitrogen, providing a monetized impact of $7014/hectare of harvestable cattail/year. The removal of phosphorus, nitrogen, carbon, and avoided flooding damages of the retention basin itself provide an additional $17,730–$18,470/hectare of retention system/year. The recommended use of retention systems is for avoided flood damages, nutrient retention, and biomass production. The revenue gained from these functions can support farmers wanting to invest in irrigation while providing economic and environmental benefits to the region.
Keywords: Surface water retention systems; Irrigation; Water management; Nutrient retention; Biomass production; Economic assessment

The present investigation emphasizes on the biosorptive removal of toxic pentavalent arsenic from water using steam activated carbon prepared from mung bean husk (SAC-MBH). Characterization of the synthesized sorbent was done using different instrumental techniques, i.e., SEM, BET and point of zero charge. Sorptive uptake of As(V) over steam activated MBH as a function of pH (3–9), agitation speed (40–200 rpm), dosage (50–1000 mg) and temperature (298–313 K) was studied by batch process at arsenic concentration of 2 mg L−1. Lower pH increases the arsenic removal over the pH range of 3–9. Among three adsorption isotherm models examined, Langmuir model was observed to show superior results over Freundlich model. The mean sorption energy (E) estimated by Dubinin–Radushkevich model suggested that the process of adsorption was chemisorption. Thermodynamic parameters confer that the sorption process was spontaneous, exothermic and feasible in nature. The pseudo-second-order rate kinetics of arsenic gave better correlation coefficients as compared to pseudo-first-order kinetics equation. Three process parameters, viz. adsorbent dosage, agitation speed and pH were opted for optimizing As(V) elimination using central composite design matrix of response surface methodology (RSM). The identical design setup was used for artificial neural network (ANN) for comparing its prediction capability with RSM towards As(V) removal. Maximum arsenic removal was observed to be 98.75% at sorbent dosage 0.75 gm L−1, pH 3.0, agitation speed 160 rpm and temperature 308 K. The study concluded that SAC-MBH could be a competent adsorbent for As(V) removal and ANN model was better in arsenic removal predictability results than RSM model.
Keywords: Biosorption; Arsenic; Mung bean husk; Thermodynamic parameters; RSM; ANN

Microbiological, physicochemical, and heavy metals assessment of groundwater quality in the Triffa plain (eastern Morocco) by Hameed Saleh Ali Yahya; Abdelhakim Jilali; Mohammed Mohammed Mohammed Mostareh; Zouheir Chafik; Abdelhafid Chafi (4497-4512).
The focus of this study is the physicochemical and bacteriological characteristics of groundwater in the Triffa plain, Morocco. In total, 34 groundwater samples were analyzed for major elements (Tp, pH, EC, K+, Na+, Ca2+, Mg2+, Cl, SO4 2−, NO3 , NO2 , NH4 +, H2PO4 , CO3, and HCO3 ) and trace metal (Al, Cd, Cu, Fe, and Zn) content. The results show that the pH values range between 6.7 and 8.9, electrical conductivity ranges between 740 and 7340 µS/cm, and nitrate content ranges between 1.7 and 212 mg/l. Hydrochemical facies represented using a Piper diagram indicate an Na–K–Cl type water. All the trace metal concentrations are within the admissible standard range except for Cd. The bacteriological analysis showed that the majority of groundwater samples are contaminated. Generally, the content of total coliforms, fecal coliforms, and fecal streptococci ranged from 0 to 140, 0 to 125, and 0 to 108 CFU/100 ml, respectively. The samples are grouped according to three factors. Factor 1 shows strong positive loadings of EC, Mg, Cl, Na and K with 51.91% of total variance (TV); factor 2 shows strong negative loadings of NO3, SO4 and Ca with 17.98% of TV; and factor 3 shows strong negative loading of HCO3 with 15.56 of TV. We conclude that the quality of this groundwater is suitable for irrigation and domestic use (cleaning house, ect).
Keywords: Groundwater; Hydrochemistry; Trace metal; Bacteriological analysis; Triffa; Morocco

Identification of artificial groundwater recharging zone using a GIS-based fuzzy logic approach: a case study in a coal mine area of the Damodar Valley, India by Ashwani Kumar Tiwari; Muriel Lavy; Gianpiero Amanzio; Marina De Maio; Prasoon Kumar Singh; Mukesh Kumar Mahato (4513-4524).
The West Bokaro coalfield is a richest coal-mining belt in the Damodar Valley, India. The extensive mining of the area has resulted in disruption of the groundwater availability in terms of both quantity and quality. This has led to a drinking water crisis, especially during the pre-monsoon period in the West Bokaro coalfield area. The characterization of the hydrogeological system and the artificial recharging of the aquifers might help to better manage the problem of the groundwater-level depletion. For this purpose, seven important hydrogeological factors (water depth, slope, drainage, soil, infiltration, lithology, and landuse) have been considered to define the most suitable locations for artificial groundwater recharging in the mining area. Different thematic maps were prepared from existing maps and data sets, remote-sensing images, and field investigations for identification of the most suitable locations for artificial recharge. Thematic layers for these parameters were prepared, classified, weighted, and integrated into a geographic information system (GIS) environment by means of fuzzy logic. The results of the study indicate that about 29 and 31% of the area are very suitable and suitable for recharging purposes in the West Bokaro coalfield. However, the rest of the area is moderate to unsuitable for recharging due to the ongoing mining and related activities in the study area. The groundwater recharging map of the study area was validated with measured electrical conductivity (EC) values in the groundwater, and it indicated that validation can be accepted for the identification of groundwater recharging sites. These findings are providing useful information for the proper planning and sustainable management of the groundwater resources in the study area.
Keywords: West Bokaro coalfield; Remote sensing; Artificial recharging; Results validation; Mining activities; Groundwater management

Heavy metals are usually released into water bodies from industrial/domestic effluents such as metal plating industries, mining and tanneries. Adsorption is a fundamental process in the physiochemical treatment of wastewaters because of its low cost. Great efforts have been made to use the economically efficient and unconventional adsorbents to adsorb heavy metals from aqueous solutions, such as plant wastes and agricultural waste. Biochar mixed with chitosan after crosslinking can be casted into membranes, beads and solutions which can be effectively utilized as an adsorbent for metal ion uptake. Keeping these facts into consideration, the present study was undertaken with the objective to determine the effect of various proportions of biochar-modified chitosan membranes on the sorption characteristics of different heavy metals like Cu, Pb, As and Cd along with comparison of sorption characteristics between industrial waste water samples containing multi-metals and standard synthetic stock solution containing a particular metal. It is apparent from the results that the bioadsorbent prepared from biochar and chitosan are low-cost efficacious resource due to its easy availability. It is also eco-friendly material for making adsorbent for abstraction of heavy metals from aqueous solution. This adsorbent can be best utilized for adsorption of heavy metals.
Keywords: Biochar; Chitosan; Adsorption; Membrane; Heavy metals

Studies on heavy metal contamination in Godavari river basin by Jakir Hussain; Ikbal Husain; Mohammed Arif; Nidhi Gupta (4539-4548).
Surface water samples from Godavari river basin was analyzed quantitatively for the concentration of eight heavy metals such as arsenic, cadmium, chromium, copper, iron, lead, nickel and zinc using atomic absorption spectrophotometer. The analyzed data revealed that iron and zinc metals were found to be the most abundant metals in the river Godavari and its tributaries. Iron (Fe) recorded the highest, while cadmium (Cd) had the least concentration. Arsenic, cadmium, chromium, iron and zinc metals are within the acceptable limit of BIS (Bureau of Indian Standards (BIS) 1050 (2012) Specification for drinking water, pp 1–5). The analysis of Godavari river and its tributary’s water samples reveals that the water is contaminated at selected points which are not suitable for drinking. Nickel and Copper concentration is above acceptable limit and other metal concentration is within the acceptable limit. Comprehensive study of the results reveals that out of 18 water quality stations monitored, water samples collected at 7 water quality stations are found to be within the permissible limit for all purposes. While Rajegaon, Tekra, Nandgaon, P. G. Bridge, Bhatpalli, Kumhari, Pauni, Hivra, Ashti, Bamini, and Jagda stations were beyond the desirable limit due to presence of copper and nickel metals. The contents of copper metal ions were higher at some water quality stations on Wunna river (Nandgaon); Wardha river (Hivra) and Wainganga river (Kumhari, Pauni, Ashti) during Feb. 2012, while nickel concentration during Feb. 2012, June 2012, March 2013 and Aug. 2013 at some water quality stations on rivers Bagh, Indravati, Pranhita, Wunna, Penganga, Peddavagu, Wainganga and Wardha. It can be concluded that rapid population growth and industrialization have brought about resource degradation and a decline in environmental quality.
Keywords: Water quality; Heavy metal; Copper; Nickel; Arsenic; Cadmium; Zinc; Iron; Pollution

The study synthesizes a low-cost adsorbent made from Mn2+-modified bentonite clay for groundwater defluoridation. The clays were characterized using X-ray diffraction, X-ray fluorescence, scanning electron microscopy, and Fourier transform infrared techniques. The fluoride adsorption capacity of the modified clay was evaluated using batch experiments. The adsorption kinetics results showed that the optimum fluoride (F) uptake was achieved within the 30 min’ contact time. The data fitted well to pseudo-second-order of reaction kinetics indicating that adsorption of F occurred via chemisorption. In addition, the adsorption isotherm data fitted well to Langmuir isotherm model indicating that adsorption occurred on a mono-layered surface. Maximum F removal of 57% was achieved from groundwater with an initial F concentration of 5.4 mg L−1 and natural pH of 8.6 using adsorbent dosage of 1 g/100 mL. Fluoride adsorption occurred through ligands and ion exchange mechanisms. The synthesized adsorbent was successfully regenerated for up to five times. The study shows that Mn2+-intercalated bentonite clay has potential for application in defluoridation of groundwater.
Keywords: Adsorption; Batch experiment; Characterization; Kinetics; Mechanism; Toxicity

Electrodialytic desalination of brackish water: determination of optimal experimental parameters using full factorial design by Soumaya Gmar; Nawel Helali; Ali Boubakri; Ilhem Ben Salah Sayadi; Mohamed Tlili; Mohamed Ben Amor (4563-4572).
The aim of this work is to study the desalination of brackish water by electrodialysis (ED). A two level-three factor (23) full factorial design methodology was used to investigate the influence of different physicochemical parameters on the demineralization rate (DR) and the specific power consumption (SPC). Statistical design determines factors which have the important effects on ED performance and studies all interactions between the considered parameters. Three significant factors were used including applied potential, salt concentration and flow rate. The experimental results and statistical analysis show that applied potential and salt concentration are the main effect for DR as well as for SPC. The effect of interaction between applied potential and salt concentration was observed for SPC. A maximum value of 82.24% was obtained for DR under optimum conditions and the best value of SPC obtained was 5.64 Wh L−1. Empirical regression models were also obtained and used to predict the DR and the SPC profiles with satisfactory results. The process was applied for the treatment of real brackish water using the optimal parameters.
Keywords: Demineralization rate; Desalination; Electrodialysis; Full factorial design; Specific power consumption

Batch sorption–desorption of As(III) from waste water by magnetic palm kernel shell activated carbon using optimized Box–Behnken design by Chinedum Anyika; Nur Asilayana Mohd Asri; Zaiton Abdul Majid; Jafariah Jaafar; Adibah Yahya (4573-4591).
In this study, we converted activated carbon (AC) into magnetic activated carbon (MAC), which was established to have removed arsenic (III) from wastewater. Arsenic (III) is a toxic heavy metal which is readily soluble in water and can be detrimental to human health. The MAC was prepared by incorporating Fe3O4 into the AC by using Fe3O4 extracted from a ferrous sulfate solution, designated: magnetic palm kernel shell from iron suspension (MPKSF). Batch experiments were conducted using two methods: (1) one-factor-at-a-time and (2) Box–Behnken statistical analysis. Results showed that the optimum conditions resulted in 95% of As(III) removal in the wastewater sample. The adsorption data were best fitted to the Langmuir isotherm. The adsorption of As(III) onto the MPKSF was confirmed by energy dispersive X-ray spectrometry analysis which detected the presence of As(III) of 0.52% on the surface of the MPKSF. The Fourier transform infrared spectroscopy analysis of the MPKSF–As presented a peak at 573 cm−1, which was assigned to M–O (metal–oxygen) bending, indicating the coordination of As(III) with oxygen through the formation of inner-sphere complexation, thereby indicating a covalent bonding between the MPKSF functional groups and As(III). The findings suggested that the MPKSF exhibited a strong capacity to efficiently remove As(III) from wastewater, while the desorption studies showed that the As(III) was rigidly bound to the MPKSF thereby eliminating the possibility of secondary pollution.
Keywords: As(III); Sorption; Desorption; Waste water treatment; Magnetic palm kernel shell activated carbon

In this study, groundwater quality of an alluvial aquifer in the western Ganges basin is assessed using a GIS-based groundwater quality index (GQI) concept that uses groundwater quality data from field survey and laboratory analysis. Groundwater samples were collected from 42 wells during pre-monsoon and post-monsoon periods of 2012 and analysed for pH, EC, TDS, Anions (Cl, SO4, NO3), and Cations (Ca, Mg, Na). To generate the index, several parameters were selected based on WHO recommendations. The spatially variable grids of each parameter were modified by normalizing with the WHO standards and finally integrated into a GQI grid. The mean GQI values for both the season suggest good groundwater quality. However, spatial variations exist and are represented by GQI map of both seasons. This spatial variability was compared with the existing land-use, prepared using high-resolution satellite imagery available in Google earth. The GQI grids were compared to the land-use map using an innovative GIS-based method. Results indicate that the spatial variability of groundwater quality in the region is not fully controlled by the land-use pattern. This probably reflects the diffuse nature of land-use classes, especially settlements and plantations.
Keywords: Groundwater quality index; Geographic information system; Land-use; Kali watershed

Hydrological characterization of the Araguaia River through reference flows by Rodolfo Rosario Klautau de Araujo Gomes; Lindemberg Lima Fernandes (4605-4614).
This study examined the hydrological behavior of the Araguaia River through reference flow, analyzing the capacity of granting the river segments in three different fluviometric stations. The study exposed the comparison of monthly and annual reference flow, considering a hydrological series of 33 years. Consequently, it was proposed seasonal flow comparing to the methodology of annual reference flow for water grants in national rivers. The adoption of the annual reference flow restricts the grants of water use in most of the time, because the proposal of monthly and seasonal Q 95% in the rainy period for grants processes showed much higher values. The proposal of monthly and seasonal reference flows to grant the multiple right of use of water may be the most adequate for power generation, because it presents the inherent characteristics of the flows of each month and per period, respectively. However, the use of seasonality for grants must be analyzed along with the environmental aspect of the river basin concerning to the damage of aquatic life of the Araguaia River.
Keywords: Fluviometric station; Reference flow; Grant; Araguaia River

Geophysical evaluation of groundwater potential in part of southwestern Basement Complex terrain of Nigeria by Olateju O. Bayewu; Moroof O. Oloruntola; Ganiyu O. Mosuro; Temitope A. Laniyan; Stephen O. Ariyo; Julius O. Fatoba (4615-4632).
The geophysical assessment of groundwater in Awa-Ilaporu, near Ago Iwoye southwestern Nigeria was carried out with the aim of delineating probable areas of high groundwater potential. The area falls within the Crystalline Basement Complex of southwestern Nigeria which is predominantly underlain by banded gneiss, granite gneiss and pegmatite. The geophysical investigation involves the very low frequency electromagnetic (VLF-EM) and Vertical Electrical Sounding (VES) methods. The VLF-EM survey was at 10 m interval along eight traverses ranging between 290 and 700 m in length using ABEM WADI VLF-EM unit. The VLF-EM survey was used to delineate areas with conductive/fractured zones. Twenty-three VES surveys were carried out with the use of Campus Ohmega resistivity meter at different location and at locations areas delineated as high conductive areas by VLF-EM survey. The result of VLF-EM survey along its traverse was used in delineating high conductive/fractured zones, it is, however, in agreement with the delineation of the VES survey. The VES results showed 3–4 geoelectric layers inferred as sandy topsoil, sandy clay, clayey and fractured/fresh basement. The combination of these two methods, therefore, helped in resolving the prospecting location for the groundwater yield in the study area.
Keywords: Groundwater potential; Resistivity survey; VES; VLF-EM; Fracture; Geoelectric layer

The study of groundwater in Amaravathi River basin of Karur District resulted in large geochemical data set. A total of 24 water samples were collected and analyzed for physico-chemical parameters, and the abundance of cation and anion concentrations was in the following order: Na+ > Ca2+ > Mg2+ > K+ = Cl > HCO3  > SO4 2−. Correlation matrix shows that the basic ionic chemistry is influenced by Na+, Ca2+, Mg2+, and Cl, and also suggests that the samples contain Na+–Cl, Ca2+–Cl an,d mixed Ca2+–Mg2+–Cl types of water. HCO3 , SO4 2−, and F association is less than that of other parameters due to poor or less available of bearing minerals. PCA extracted six components, which are accountable for the data composition explaining 81% of the total variance of the data set and allowed to set the selected parameters according to regular features as well as to evaluate the frequency of each group on the overall variation in water quality. Cluster analysis results show that groundwater quality does not vary extensively as a function of seasons, but shows two main clusters.
Keywords: Amaravathi River; Cluster analysis; Correlation matrix; Karur; Spatial distribution

Heavy metal concentration in groundwater from Besant Nagar to Sathankuppam, South Chennai, Tamil Nadu, India by S. G. D. Sridhar; A. M. Sakthivel; U. Sangunathan; M. Balasubramanian; S. Jenefer; M. Mohamed Rafik; G. Kanagaraj (4651-4662).
The assessment of groundwater quality is an obligatory pre-requisite to developing countries like India with rural-based economy. Heavy metal concentration in groundwater from Besant Nagar to Sathankuppam, South Chennai was analyzed to assess the acquisition process. The study area has rapid urbanization since few decades, which deteriorated the condition of the aquifer of the area. Totally 30 groundwater samples were collected during pre-monsoon (June 2014) and post-monsoon (January 2015) from the same aquifer to assess the heavy metal concentration in groundwater. Groundwater samples were analyzed for heavy metals such as Fe, Pb, Zn, Cu, Ni, Cr, Co and Mn using atomic absorption spectrophotometry (AAS). Correlation matrix revealed that there is no significant correlation between heavy metals and other parameters during pre-monsoon except EC with Cr but Fe and Zn have good positive correlation during post-monsoon.
Keywords: Groundwater; Heavy metals; BIS; Spatial distribution; Correlation matrix

Assessment of hydro-geochemistry and groundwater quality of Rajshahi City in Bangladesh by M. G. Mostafa; S. M. Helal Uddin; A. B. M. H. Haque (4663-4671).
The study was carried out to understand the hydro-geochemistry and ground water quality in the Rajshahi City of Bangladesh. A total of 240 groundwater samples were collected in 2 years, i.e., 2009 and 2010 covering the pre-monsoon, monsoon and post-monsoon seasons. Aquifer soil samples were collected from 30 locations during the monsoon in 2000. All the samples were analyzed for various physicochemical parameters according to standard methods of analysis, these includes pH, electrical conductivity, total dissolved solids, total hardness, and total alkalinity, major cations such as Na+, K+, Ca2+, Mg2+, and Fe2+, major anions such as HCO3 , NO3 , Cl, and SO4 2− and heavy metals such as Mn, Zn, Cu, As, Cd and Pb. The results illustrated that the groundwater was slightly acidic to neutral in nature, total hardness observed in all samples fall under the hard to a very hard category. The bicarbonate and calcium concentration in the groundwater exceeded the permissible limits may be due to the dissolution of calcite. The concentration of calcium, iron, manganese, arsenic and lead were far above the permissible limit in most of the shallow tube well samples. The study found that the major hydrochemical facies was identified to be calcium-bicarbonate-type (CaHCO3). A higher concentration of metals including Fe, Mn, As and Pb was found indicating various health hazards. The rock–water interaction was the major geochemical process controlling the chemistry of groundwater in the study area. The study results revealed that the quality of the groundwater in Rajshahi City area was of great concern and not suitable for human consumption without adequate treatment.
Keywords: Physicochemical; Groundwater; Geochemistry; Rajshahi City; Tube well

Fluoride pollution in groundwater is a major concern in rural areas. The flower petal of Shorea robusta, commonly known as sal tree, is used in the present study both in its native form and Ca-impregnated activated form to eradicate excess fluoride from simulated wastewater. Response surface methodology (RSM) was used for experimental designing and analyzing optimum condition for carbonization vis-à-vis calcium impregnation for preparation of adsorbent. During carbonization, temperature, time and weight ratio of calcium chloride to sal flower petal (SFP) have been considered as input factors and percentage removal of fluoride as response. Optimum condition for carbonization has been obtained as temperature, 500 °C; time, 1 h and weight ratio, 2.5 and the sample prepared has been termed as calcium-impregnated carbonized sal flower petal (CCSFP). Optimum condition as analyzed by one-factor-at-a-time (OFAT) method is initial fluoride concentration, 2.91 mg/L; pH 3 and adsorbent dose, 4 g/L. CCSFP shows maximum removal of 98.5% at this condition. RSM has also been used for finding out optimum condition for defluoridation considering initial concentration, pH and adsorbent dose as input parameters. The optimum condition as analyzed by RSM is: initial concentration, 5 mg/L; pH 3.5 and adsorbent dose, 2 g/L. Kinetic and equilibrium data follow Ho pseudo-second-order kinetic model and Freundlich isotherm model, respectively. Adsorption capacity of CCSFP has been found to be 5.465 mg/g. At optimized condition, CCSFP has been found to remove fluoride (80.4%) efficiently from groundwater collected from Bankura district in West Bengal, a fluoride-contaminated province in India.
Keywords: Fluoride; Shorea robusta flower petal; Response surface methodology; Adsorption; Isotherm; Thermodynamics

Virtual water content for meat and egg production through livestock farming in Saudi Arabia by Shakhawat Chowdhury; Omar K. M. Ouda; Maria P. Papadopoulou (4691-4703).
The concept of virtual water content (VWC) may facilitate an understanding of total water demand for commodity production. The water consumption for livestock production forms a significant fraction of freshwater demand in arid regions, i.e., Saudi Arabia. In this paper, VWC was estimated for different livestocks in the 13 regions of Saudi Arabia. The VWC for camel production was also estimated, which has not been investigated in the previous studies. The overall VWC for livestock in Saudi Arabia was about 10.5 and 8.9 billion m3 in 2006 and 2010, respectively. This study shows the decreasing trend of overall VWC in producing livestock in Saudi Arabia. The VWC were highest in Riyadh followed by Eastern region, Qaseem, Hail, and Makkah with ranges of 3587–4112, 1684–2044, 1007–1331, 644–810, and 504–715 million m3/year, respectively. The results demonstrate that a shift in diet from the high VWC meat to low VWC meat may reduce the overall VWC for livestock production. The findings of this analysis provide an assessment of the quantity and trend of water demand for livestock production in Saudi Arabia, which is useful to assess the development of an information-based agricultural water management strategy.
Keywords: Virtual water content; Water saving; Water resources management; Arid region; Livestock farming; Water demand

This study was carried out employing vertical electrical sounding (VES) with Schlumberger electrode configuration. The objectives were to investigate the distribution of the geohydraulic parameters and the corrosivity of the aquifer layer within the study area. The sand-to-coarse grain sands aquifer have resistivity ranging from 8.1 to 2204 Ωm, while the thickness ranged from 7.4 to 55.3 m. These parameters were used in computing the geohydraulic parameters. Hydraulic conductivity was estimated using the Heigold equation, and its values ranged from 1.42 to 54.90 m/day. Estimated hydraulic conductivity values were employed in determining the aquifer transmissivity which ranged from 11.28 to 812.00 m2/day, fractional porosities ranged from 0.0351 to 0.0598. The longitudinarl conductance also varies from 0.01 to 1.83 Ω−1. The contour plots generated from the SURFER software package show the variation of these parameters. The ranges of these estimated parameters indicate variation in grain sizes, magnitude of pore sizes and facies changes. The corrosivity rating indicates that most of the VES points were practically non-corrosive.
Keywords: Aquifer; Geohydraulic properties; Transmissivity; Hydraulic conductivity; Porosity

Sugar industry is a very important agro-based industry in India and it discharges large amount of effluent into water bodies to create high pollution in water bodies which affects the plants and other living organisms. In the present investigation, the physico-chemical analyses of N. P. K. R. Ramaswamy co-operative sugar mill effluent was determined and impact of different concentrations (control, 10, 25, 50, 75 and 100%) of sugar mill effluent on seed germination behavior of African marigold (Tagetes erecta L.) was studied. The morphological parameters such as germination percentage, shoot length, root length, fresh weight and dry weight of seedlings, seed vigour index, tolerance index and percentage of phytotoxicity were calculated. The results recorded for the analyses of sugar mill effluent indicated their some parameters such as PH, EC, acidity, TDS, TS, BOD, COD, sulphate, magnesium, nitrogen, zinc, iron, copper, lead, manganese and oil and grease exceeded the permissible limit compared to Tamil Nadu Pollution Control Board (TNPCB) and then germination and growth parameters increased in lower (10%) concentration of sugar mill effluent and this morphological parameters gradually decreased with increasing effluent concentration. The lower (10%) concentration of sugar mill effluent may be used for irrigation purposes.
Keywords: African marigold; Germination; Physico-chemical analysis; Phytotoxicity and sugar mill effluent

Surface waters, especially rivers are the most important sources of water supply for drinking and agricultural purposes. Water with desirable quality is necessary for human life. Therefore, knowledge of water quality and its temporal changes is of particular importance in sustainable management of water resources. In this study, available data during 20 years from two hydrometry stations located in the way of Horroud River in Lorestan province were used and analyzed using Aq.QA software. Piper, Schoeller, Stiff, and Wilcox diagram were drawn and Mann–Kendal test was used for determining data trend. According to Wilcox diagram, water of this river in both stations is placed in c2s1 class which is good for agricultural purposes, and according to Schoeller diagram, there is no restrict for drinking purposes. Results of Man–Kendal test show increasing trend for colorine, EC, TDS while decreasing trend for potassium in Kakareza station. On the other hand in Dehnu station, positive trend was seen in calcium and colorine while negative trend for sulfate and potassium. For other variables, no specific trend was found.
Keywords: Chemical quality; Mann–Kendall test; Aq.QA; Data trend; Wilcox diagram

The present study deals with the groundwater quality with respect to F in the Mandavi Taluka of Surat city with an objective to analyze the spatial variability of ground water quality parameter. A total 57 representative groundwater samples from different bore wells and hand pumps were collected during pre-monsoon. Samples were analyzed for various physiochemical parameters including fluoride. GIS technique is adopted to prepare DEM and spatial distribution map of fluoride to represent fluoride concentration in the study area. Results obtained from analysis with GIS mapping reveal that fluoride in the study is mainly attributed to geogenic source.
Keywords: Groundwater; Fluoride; Spatial distribution; Geographic information system (GIS)

Refined natural Fe-chromite was characterized by XRD, FT-IR, reflected polarized microscope, XRF and UV spectrophotometer. Photocatalytic degradation and photo-Fenton oxidation of Congo red dye by Fe-chromite was investigated using 1 mL H2O2. The degradation of dye was studied as a function of illumination time, chromite mass, initial dye concentration, and pH. Fe-chromite acts as binary oxide system from chromium oxide and ferrous oxide. Thus, it exhibits photocatalytic properties under UV illumination and photo-Fenton oxidation after addition of H2O2. The degradation in the presence of H2O2 reached the equilibrium stage after 8 h (59.4%) but in the absence of H2O2 continued to 12 h (54.6%). Photocatalytic degradation results fitted well with zero, first order and second order kinetic model but it represented by second order rather than by the other models. While the photo-Fenton oxidation show medium fitting with the second order kinetic model only. The values of kinetic rate constants for the photo-Fenton oxidation were greater than those for the photocatalytic degradation. Thus, degradation of Congo red dye using chromite as catalyst is more efficient by photo-Fenton oxidation. Based on the response surface analysis, the predicted optimal conditions for maximum removal of Congo red dye by photocatalytic degradation (100%) were 12 mg/l, 0.14 g, 3, and 11 h for dye concentration, chromite mass, pH, and illumination time, respectively. Moreover, the optimum condition for photo-Fenton oxidation of dye (100%) is 13.5 mg/l, 0.10 g, 4, and 10 h, respectively.
Keywords: Chromite; Binary oxide; Congo red dye; Photocatalysis; Photo-Fenton oxidation

Satopanth Lake is a glacial lake, located at an altitude of 4600 m above sea level in Garhwal Himalaya of Uttarakhand state in India where an attempt was made to assess the water quality. A total of sixteen physico-chemical parameters including temperature, hardness, alkalinity, dissolved oxygen, conductivity, pH, calcium, magnesium, chlorides, nitrates, sulphates and phosphates were recorded during 2014 and 2015 between June and August in ice-free period. The mean values of pH ranged from 6.85 to 7.10; water temperature fluctuated from 0.1 to 0.3 °C; dissolved oxygen varied from 5.90 to 6.0 mg.L−1; free CO2 varied from 8.40 to 8.60 mg.L−1; total dissolved solids varied from 88.0 to 89.5 mg.L−1; calcium from 7.88 to 7.95 mg.L−1; magnesium from 0.53 to 0.66 mg.L−1. All the physico-chemical values were within the prescribed WHO/BIS limit for drinking water. Water Quality Index (WQI) calculated based on these parameters also revealed the excellent quality of lake water.
Keywords: Water quality; Satopanth Lake; Garhwal Himalaya; Uttarakhand; India

Statistical distribution of rainfall in Uttarakhand, India by Vikram Kumar; Shanu; Jahangeer (4765-4776).
Understanding of rainfall is an important issue for Uttarakhand, India which having varied topography and due to that extreme rainfall causes quick runoff which warns structural and functional safety of large structures and other natural resources. In this study, an attempt has been made to determine the best-fit distribution of the annual series of rainfall data for the period of 1991–2002 of 13 districts of Uttarakhand. A best-fit distribution such as Chi-squared, Chi-squared (2P), exponential, exponential (2P), gamma, gamma (3P), gen. extreme value (GEV), log-Pearson 3, Weibull, Weibull (3P) distributions was applied. Comparisons of best distributions were based on the use of goodness-of-fit tests such as Kolmogorov–Smirnov, Anderson–Darling, and Chi squared. Results showed that the Weibull distribution performed the best with 46% of the total district, while the second best distribution was Chi squared (2P) and log-Pearson. The results of this study would be useful to the water resource engineers, policy makers and planners for the agricultural development and conservation of natural resources of Uttarakhand.
Keywords: Best-fit distribution; Anderson–Darling; Chi square; Kolmogorov–Smirnov

In recent years, and under constraints caused by persistent drought, Algeria has launched a new mobilization strategy for surface water resources from small and medium dams. However, by making a review of the studies and achievements of twenty small dams in the west of Algeria, some deficiencies appeared. In addition to reservoir siltation assessment, operation spillways have been the major constraint on the reliability of these types of dams. The objective of this paper is to use the roller compacted concrete (RCC) for small dams’ design for the benefit it offers and its ability to incorporate spillways. The development of this reflection was applied to the Khneg Azir earth dam situated in southwest of Algeria. Its uncontrolled lateral spillway has registered significant damage following the flood of October 2005, amounted, at that time, to more than 100 million Algerian dinars (1 million US Dollars). The present research encompasses a technical and economical comparative analysis concerning multiple criteria dam design types coupled with the conjugation of the spillways. Thus, on the basis of financial estimates calculated for all design types, the variant RCC remains competitive with that of the earth dam’s spillway isolated (Less than 40% of the cost). To assess the mechanical behavior of the foundations for both types of dams, (earth and RCC dams), numerical modeling has been undertaken, according to the comparative analysis of deformations in the foundations. Analysis of deformations showed that the average foundation deformations was between (0.052–0.85) m for earth dam and (0.023–0.373) m for RCC dam. These economical and technical considerations open up important prospects for the use of RCC in the design of small dams.
Keywords: Earth dam; RCC dam; Frontal spillway; Lateral spillway; Deformations

River systems constitute areas of high human population densities owing to their favourable conditions for agriculture, water supply and transportation network. Despite human dependence on river systems, anthropogenic activities severely degrade water quality. The main aim of this study was to assess the river health of Ngamo River using diatom and macroinvertebrate community structure based on multivariate analyses and community metrics. Ammonia, pH, salinity, total phosphorus and temperature were found to be significantly different among the study seasons. The diatom and macroinvertebrate taxa richness increased downstream suggesting an improvement in water as we moved away from the pollution point sources. Canonical correspondence analyses identified nutrients (total nitrogen and reactive phosphorus) as important variables structuring diatom and macroinvertebrate community. The community metrics and diversity indices for both bioindicators highlighted that the water quality of the river system was very poor. These findings indicate that both methods can be used for water quality assessments, e.g. sewage and agricultural pollution, and they show high potential for use during water quality monitoring programmes in other regions.
Keywords: Water quality; Bioindicators; Macroinvertebrates; Diatoms; Nutrients; Multivariate analysis

A comparison of the linear and non-linear regression method in selecting the optimum isotherm among three most commonly used adsorption isotherms (Langmuir, Freundlich, and Redlich–Peterson) was made to the experimental data of fluoride (F) sorption onto Bio-F at a solution temperature of 30 ± 1 °C. The coefficient of correlation ( $$r^{2}$$ r 2 ) was used to select the best theoretical isotherm among the investigated ones. A total of four Langmuir linear equations were discussed and out of which linear form of most popular Langmuir-1 and Langmuir-2 showed the higher coefficient of determination (0.976 and 0.989) as compared to other Langmuir linear equations. Freundlich and Redlich–Peterson isotherms showed a better fit to the experimental data in linear least-square method, while in non-linear method Redlich–Peterson isotherm equations showed the best fit to the tested data set. The present study showed that the non-linear method could be a better way to obtain the isotherm parameters and represent the most suitable isotherm. Redlich–Peterson isotherm was found to be the best representative ( $$r^{2}$$ r 2  = 0.999) for this sorption system. It is also observed that the values of $$eta$$ β are not close to unity, which means the isotherms are approaching the Freundlich but not the Langmuir isotherm.
Keywords: Sorption; Bio-F; Fluoride; Equilibrium isotherm; Linear regression; Non-linear regression

Assessing the effectiveness of pollutant removal by macrophytes in a floating wetland for wastewater treatment by Meera Prajapati; Johan J. A. van Bruggen; Tatenda Dalu; Rabin Malla (4801-4809).
The study aimed to evaluate the removal of pollutants by floating treatment wetlands (FTWs) using an edible floating plant, and emergent macrophytes. All experiments were performed under ambient conditions. Physico-chemical parameters were measured, along with microbiological analysis of biofilm within the roots, water column, and sludge and gravel zone. Nitrification and denitrification rates were high in the water zone of Azolla filiculoides, Lemna minor, Lactuca sativa, P. stratiotes, and Phragmites australis. Phosphate removal efficiencies were 23, 10, and 15% for the free-floating hydrophytes, emergent macrophytes, and control and edible plants, respectively. The microbial community was relatively more active in the root zone compared to other zones. Pistia stratiotes was found to be the efficient in ammonium (70%) and total nitrogen (59%) removal. Pistia stratiotes also showed the highest microbial activity of 1306 mg day−1, which was 62% of the total volume. Microbial activity was found in the water zone of all FTWs expect for P. australis. The use of P. stratiotes and the edible plant L. sativa could be a potential option to treat domestic wastewater due to relatively high nutrient and organic matter removal efficiency.
Keywords: Denitrification; Floating treatment wetlands (FTWs); Macrophytes; Microbial activity; Nitrification