Applied Water Science (v.8, #5)

Statistical analysis of Litchi chinensis’s adsorption behavior toward Cr(VI) by Mohammad Kashif Uddin; Mukhtar M. Salah (1-9).
The adsorption results of Cr(VI) removal from aqueous solutions on Litchi chinensis have been optimized by the Box–Behnken design of response surface methodology. Three experimental parameters (dose, temperature, and pH) were chosen as independent variables. The maximum Cr(VI) adsorption was obtained at the initial pH of 2. Analysis of variance (ANOVA) of the results was successfully used to check the significance of the independent variables and their interactions. The three-dimensional (3D) response surface plots were used to study the interactive effects of the independent variables on % Cr(VI) removal. These figures successfully interpret the effect of interaction between pH (0.1–1.0), adsorbent dose (0.1–1.0 g.) and temperature (0–50 °C). The second-order polynomial equation was generated for the response. A statistical hypothesis test was conducted to critically analyze the experimental data by applying t test, paired t test, and Chi-square test. The comparison of t-calculated and t-tabulated values showed that the results were in favour of the conducted experiment.
Keywords: Litchi chinensis ; Box–Behnken design; Statistical analysis; Hypothesis test

A screen-printed electrode modified with zirconium antimonate ionophore was fabricated for the quantification of Hg(II) ion. The modified electrode revealed linear response in a wide concentration range of 5 × 10−8–1 × 10−1 mol/L at 25 °C of Hg(II) with a slope of 30.02 ± 0.75 mV/decade with detection limit of 5 × 10−8 mol/L. The electrode can be used in the pH range 2.5–8.5. Selectivity coefficients were assessed using fixed interference and matched potential techniques. The electrode stability was maintained for 16 weeks. This modified electrode was allowed to determine Hg(II) ions in different media such as water, dental amalgam and fish tissue. An inductively coupled plasma-optical emission spectrometry confirmed the efficiency and accuracy of the nominated modified electrode.
Keywords: Screen-printed ion-selective electrode; Zirconium antimonate ionophore; Mercury determination; Water samples

Intrinsic vulnerability assessment for the Quaternary aquifer in Baghdad area using DRASTIC model by Inass Abdal Razaq Al-Mallah; Wasan Sabeh Al-Qurnawi (1-14).
The assessment of groundwater vulnerability to pollution considered an effective tool in managed water resources especially in arid and semi-arid areas. The main objective of this study is to appraise the vulnerability for the Quaternary aquifer in Baghdad region, by using DRASTIC model and GIS for both the standard and pesticide conditions to evaluate the most sensitive and effective areas to pollution. The vulnerability index map for the standard and pesticide conditions shows three classes of very low, low, and moderate and low, moderate, and high classes, respectively, where the DRASTIC pesticide index ratio represents 33% more than the DRASTIC standard index. The results showed that the most vulnerable areas of the standard condition were constructed in two regions, the North West part and the second area that represented in the middle part of the study area, besides the high pesticide vulnerable index with 48% of the study area at the same parts. Topography, soil media, and water depth are the main factors that affect the groundwater contamination of the Quaternary aquifer and make it more susceptible to pollution; therefore, it is necessary to maintain these susceptible areas from agricultural results, seepage, and effluent from the residual wastes which spilt from the uncontrolled industries distributed in the area.
Keywords: Iraq; Baghdad; Quaternary; Groundwater; Vulnerability; DRASTIC

A huge amount of water is consumed in the textile industry, and the result is the production of a large amount of wastewater. The treatment of such wastewater significantly reduces the pollution load. Oxidation by nano-Fenton reactions (Fe3+/H2O2) is a reasonable and cost-efficient process for the remediation of harmful pollutants in wastewater. In the present study, nano-hematite was applied as a source of iron in Fenton’s reagent for methylene blue dye removal from wastewater. The effects of different parameters, presence of nano-hematite, hydrogen peroxide concentrations and pH, were optimized using the response surface methodology technique. A Box–Behnken design was applied, and the response (dye removal) was maximized. A maximal dye removal (81.6%) was attained when wastewater was treated at pH 2.5 in the presence of nano-hematite and hydrogen peroxide in the amounts of 41 and 388 mg/L, respectively. The model is well fitted and described using the second-order polynomial equation. Moreover, the model validation showed a 97% fit between the theoretical and experimental ones.
Keywords: Methylene blue dye; Photo-Fenton; Nano-hematite; Response surface methodology (RSM); Statistical optimization

The Fenton’s oxidation process has been found to be a simple and economical method for the treatment of nitroaromatic compounds in water. In the present study, the iron extracted from the laterite soil was used as a catalyst and optimization of pH, hydrogen peroxide concentration and iron concentration was studied for different initial concentrations of 2-nitroaniline (2-NA), 3-nitroaniline (3-NA) and 4-nitroaniline (4-NA). The optimum pH obtained was 2.5 for 2-NA and 3-NA and 3 for 4-NA. The maximum removal efficiency obtained was 85.3%, 84.3% and 98.7% for 0.5 mM initial concentration at a hydrogen peroxide concentration of 3.5 mM, 4.5 mM and 5 mM for 2-NA, 3-NA and 4-NA, respectively, with a constant iron concentration of 0.05 mM.
Keywords: Nitroaromatic compounds; Degradation; Fenton’s oxidation; Iron from laterite as a catalyst

Shortage of water for industrial and commercial use and even for drinking purpose is a concern throughout the world, especially in developing countries. The current decline in groundwater availability in India necessitates the formulation of sustainable groundwater management plan through proper assessment of the available resources. Rainwater harvesting (RWH) for groundwater recharge is seen as one of the solutions to solve the groundwater problem. This is reflected in an increase in watershed development programs, in which RWH is an important structural component. Understanding the net effect of these development programs is crucial to ensure that net effect on groundwater is positive both locally and within a watershed. The appropriate design and evaluation of a RWH system is necessary to improve system performance and the stability of the water supply. This review article is focused on a literature survey of the design of RWH and its aquifer modeling and application of remote sensing and geographic information system to artificial recharge.
Keywords: Aquifer; Modeling; Rainwater harvesting; Groundwater

The study was aimed at assessing the vertical movement of leachate from 2001 through 2015, and groundwater physicochemical parameters analysis around the Olusosun dumpsite, through a time-lapse study. Tracking the leachate vertical migration profile was achieved through analysis of VES time-lapse data obtained from previous investigations on the dumpsite between 2001 and 2006, and 2D resistivity data acquired from this study in 2014 and 2015. Seventeen borehole and hand-dug well water samples were obtained randomly from 17 sampling locations around the dumpsite, first, in August 2014 (wet season) and then a repeat in December 2015 (dry season). The results of the VES data and 2D resistivity analysis showed that there is a constant and progressive increase in the depth of migration of the contaminants generated on this site into the subsurface environment over the years. It also showed that the contaminated zones are characterised by resistivity values ranging from 0.63 to 12.5 Ωm, and a maximum depth of 120 m has been impacted by the contaminants. The results of the water sample analysis showed clear variations for the various elemental constituents analysed for. Most of the physicochemical parameters analysed fell within the World Health Organisation (WHO) and the Nigerian Standard for Drinking Water Quality (NSDWQ) standard limit. Comparing the wet and dry season results, there was generally an increase in the mean concentrations of TDS, EC, temperature, hardness, Ca2+, Mg2+, K+, Na+,$$ { ext{Cl}}^{ - } $$ Cl- ,$$ { ext{NO}}_{3}^{ - } $$ NO3- , Zn, Cu, Pb and Cr from the dry season study, particularly the samples with close proximity to the dumpsite. On the other hand, there was reduction in the mean concentrations of $$ { ext{SO}}_{4}^{2 - } $$ SO42- ,$$ { ext{PO}}_{4}^{3 - } $$ PO43- , Fe, pH, and Ni from the dry season study when compared with the wet season. This trend could be attributed to the fact that in the absence of rainfall during the dry season period, contaminant accumulation in groundwater continued undiluted due to continuous breakdown of the biodegradables units with time, and this led to the generally high concentration of the physicochemical properties during the dry season. The implication is that the water around the study area has lower quality in the drier season when compared to the quality of water during the wet season, and so water treatment should be given more priority during the dry season before consumption and usage for other domestic purposes to avoid waterborne diseases. Generally, the information obtained from the geophysical study will facilitate decisions on improving protection for groundwater resources around the study area.
Keywords: Concentration; Physicochemical; Landfill; Wet season; Dry season

The present study confers the chemical quality of groundwater and surface water of Mothkur region, Telangana State, for drinking and irrigational purposes. Mothkur region is geologically occupied by the Archaean crystalline terrain. Most of the population depends on groundwater for their daily needs especially for drinking, house needs and irrigation purposes. For this reason, twenty-five groundwater and five surface water samples were collected and analysed for pH, electrical conductivity, total dissolved solids (TDS), total hardness (TH) bicarbonate (HCO3 ), chloride (Cl), sulphate (SO4 2−), fluoride (F), calcium (Ca2+), magnesium (Mg2+), sodium (Na+) and potassium (K+). The results are evaluated and compared with WHO and BIS water quality standards. Based on obtained results 32%, 20%, 28% and 4% of groundwater samples are not recommended for drinking with reference to the concentrations of fluoride, TDS, TH and Cl, respectively. Base-exchange indices and meteoric genesis indices classified 67% and 33% of the water sources as the Na+–HCO3 type and deep meteoric water percolation type, respectively. Piper trilinear diagram for geochemical classification indicates 44% and 60% of groundwater and surface water samples of Ca2+–Na+–HCO3 type and 29% belong to Na+–HCO3 types. Multivariate graphical methods have been carried out using the United States Salinity Laboratory diagram, Wilcox diagram, sodium adsorption ratio, per cent sodium (%Na), residual sodium carbonate and permeability index which indicate that majority of groundwater samples are useful for irrigation purposes.
Keywords: Hydrochemistry; Groundwater quality; Sodium adsorption ratio (SAR); Per cent sodium (%Na); Residual sodium carbonate (RSC); Permeability index (PI); Mothkur region; South India

We carry out a study of the statistical distribution of rainfall precipitation data for 20 cites in India . We have determined the best-fit probability distribution for these cities from the monthly precipitation data spanning 100 years of observations from 1901 to 2002. To fit the observed data, we considered 10 different distributions. The efficacy of the fits for these distributions was evaluated using four empirical nonparametric goodness-of-fit tests, namely Kolmogorov–Smirnov, Anderson–Darling, Chi-square test, Akaike information criterion, and Bayesian information criterion. Finally, the best-fit distribution using each of these tests were reported, by combining the results from the model comparison tests . We then find that for most of the cities, generalized extreme value distribution or inverse Gaussian distribution most adequately fits the observed data .
Keywords: Rainfall statistics; KS test; Anderson–Darling test; AIC; BIC

Proper treatment of heavy metal ions present in wastewaters is a major concern. With extensive usage in various industries, Cr(VI) contamination has become threatening for the environment. Biosorption is a favorable technique for heavy metals removal. In the present study, dried cyanobacterial consortium of Dinophysis caudata and Dinophysis acuminata were used to assess its biosorption capability. The surface texture and morphology of the biosorbent were obtained through scanning electron microscopy. The presence of different chemical bonds, namely hydroxyl, C–H and C–N, was confirmed through FTIR study. Pseudo-second-order Mckay-Ho model was found to perform best to fit the kinetic data. Temkin adsorption isotherm model fit best to the equilibrium data. Response surface methodology (RSM) was employed to optimize Cr(VI) abatement. Effect of initial concentration (IC) of metal ion, temperature, pH variation and amount of adsorbent (AD) were studied during batch study. Maximum Cr(VI) abatement after 5 min contact time was 80.77% for an IC of Cr(VI) of 25 mg/L, at pH 11 and 45 °C with the AD of 2.5 g/L. The optimum removal conditions as shown by RSM study were IC of Cr(VI): 15 mg/L, AD: 1 g/L, pH: 11, and the removal was predicted as 81.72%. Artificial neural network-based model was further developed based on experimental points which indicated that the model can predict abatement of Cr(VI) for various operating conditions with reasonably high accuracy.
Keywords: Artificial neural network; Biosorption; Chromium; Cyanobacteria; Response surface methodology

A survey on microbial quality and antibiotic resistance in Karoon River, Khuzestan, Iran by Sotoodeh Besharati; Hossein Motamedi; Roya Zallaghi (1-6).
Karoon River is the most important river in Iran that supplies the drinking and industrial water to many cities and villages in Khuzestan. As a consequence of hospital and municipal wastewater discharge into this river, antibiotic resistance will be increased in microbial inhabitants of this ecosystem. Furthermore, microbial load is also undergone continual variation. The aim of this study was to evaluate seasonal microbial quality and antibiotic resistance in bacterial isolates. For this purpose, five stations were selected and samples were harvested during four seasons. Bacterial count was performed through culturing on Mueller–Hinton agar, and bacterial isolates were identified. Antibiotic resistance profiles of isolates as well as resistance to Hg were investigated. As a result, it was found that the least quality was in summer season while the best quality was in winter that is related to the reduction of water volume and recreational activities in summer and increasing rain and dilution of contaminants in winter season. All isolates were sensitive to Hg while antibiotic resistance and multidrug resistance were found in bacterial isolates. Based on the obtained results, it can be concluded that the microbial quality of Karoon River has variations depending on the season and it is necessary that be monitored in order to control and prevent epidemic bacterial infections and antibiotic resistance distribution.
Keywords: Karoon River; Microbial quality; Antibiotic resistance; Multidrug resistance; Heavy metal resistance

Simulation of surface runoff in Karaj dam basin, Iran by Maryam Alipour; Majid Hosseini (1-10).
A major part of the Iranian capital drinking water is supplied from Karaj reservoir 100 km northwest of Tehran. This reservoir collects water from 849 km2-catchment which is undergoing accelerated changes due to deforestation and urbanization. The main objective of this study is to develop a catchment modeling platform which translates ongoing land-use changes, soil data, precipitation and evaporation into surface runoff of the river discharging into the reservoir: Soil and Water Assessment Tool, SWAT, model along with hydro-meteorological records of 1997–2011. A variety of statistical indices were used to evaluate the simulation results for both calibration and validation periods; among them, the robust Nash–Sutcliffe coefficients were found to be 0.58 and 0.62 in the calibration and validation periods, respectively. This project has developed a reliable modeling platform with the benchmark land physical conditions of the Karaj dam basin.
Keywords: SWAT model; Land-use change; Rainfall-runoff modeling; Sensitivity analysis; SWAT-CUP; SUFI-2

China’s urbanization has always required the support of rural areas. By 2014, urban wastewater pollution had become a serious problem in China and this drew the public’s attention to the urban water environment. As a result, the government now requires a new type of urbanization, with simultaneous development of high-quality rural areas. Improving the economic, social and environmental influence of urban development on rural areas helps to improve urbanization and make rural areas more sustainable. This article focuses on a particular question: Have urban wastewater emissions affected the efficiency of agricultural water use? Using provincial panel data for 2004–2010, we analyze how the increase in the urban wastewater treatment ratio has changed China’s agricultural water productivity. The effect is shown to be prominent, irrespective of whether the urbanization ratio is high or low. This effect is most significant when the urbanization ratio is highest or when society pays more attention to urban environmental governance. The influence has regional heterogeneity and is also affected by various other policy settings. The results provide helpful guidance for cities as they focus on rural impacts as part of the new type of urbanization policies.
Keywords: Urban wastewater treatment ratio; Agricultural water productivity; Urbanization; Agricultural water

Smartphone-based System for water quality analysis by Satyam Srivastava; Saikrishna Vaddadi; Shashikant Sadistap (1-13).
Water quality in rural areas is difficult to monitor due to lack of connectivity from different water laboratories. In other areas, location-based real-time water quality data collection is a tedious job and highly dependent on human intervention. The presented paper introduces a low-cost battery operated smartphone-based embedded system design to measure different water quality parameters in various remote locations. Developed system measures pH, total dissolved salt (TDS) and temperature of the water samples using off the shelf available sensors. Measured pH and TDS dataset have been used to derive other water quality parameters using standard mathematical relationships such as salinity, oxygen reduction potential and conductivity. Front-end readout interface circuit has been designed and interfaced with 8-bit microcontroller along with classical Bluetooth module for measurement, data acquisition, and logging purpose. A dedicated smartphone-based application offers analysis and cloud data storage possibilities. It also provides facility to analyze water quality data with location information on Google map for quick judgment and easy understanding. The developed smartphone-based application provides the facility of auto-calibration feature for rapid and on-site usage. Developed smartphone-based application also opens up the possibility to share the data and warnings using different options such as SMS, WhatsApp and E-mail. Overall device has dimensions of 11.0 × 8.0 × 4.0 (in cm), weighs 350 g and runs with 9-V rechargeable battery. Obtained results have been validated with standard water quality measurement system from Eutech Instruments, and it has been observed that measured and calculated parameters are acceptable according to Indian water quality standards. Various statistical and artificial neural network-based modeling techniques have been used to convert measured water quality parameters to a single water quality index for easy and rapid judgment. The developed water quality measurement system has been used for multiple applications to explore the utility of the system such as instant water quality judgment and real-time water quality analysis of different water sources. One of the other explored applications is the real-time water quality monitoring of small ponds and lakes.
Keywords: Water quality sensors; Portable embedded system; Water quality index

New technology has provided a cheap and abundant access to nanoclay which has more prominent and efficient properties than clay. The aim of this research was a performance review of clay and nanoclay granules for the purpose of improving physicochemical as well as biological quality of water. To this end, clay granules and a 50% composition of clay and nanoclay with an average of a 5-mm diameter were made and placed in the 1000 °C furnace for 7 h. 150 g of any kind of granule was put in a closed system with presence of 300 ml of sample of synthesized contaminated water for 24 h. Then, heavy metals (lead and arsenic), anions (nitrate), turbidity, electrical conductivity and microbial contamination (coliforms) were measured. The clay and nanoclay granules had adsorbed the lead, respectively, with 0/4 and /44 mg/l by 80% and 88% yield. They have been almost effective in declining nitrate, arsenic, turbidity, and electrical conductivity, though ineffective in removal of microbial contamination. The results show that the adsorption yield for nanoclay is much higher than that for clay.
Keywords: Clay; Nanoclay; Water treatment; Ceramic; Arsenic

Assessment of groundwater quality in hard rock aquifer of central Telangana state for drinking and agriculture purposes by Annadasankar Roy; Tirumalesh Keesari; Hemant Mohokar; Uday Kumar Sinha; Sadasiva Bitra (1-18).
Quality assessment of groundwater for drinking and irrigation was evaluated in parts of Nalgonda district of Telangana state, India. The overall groundwater quality and the suitability to drinking and irrigation were evaluated by hydrochemical analysis of 78 groundwater samples. The water quality parameters were compared with that of the limits set by World Health Organisation (WHO) and Bureau of Indian Standards (BIS). Groundwater is found to be contaminated by fluoride and nitrate ions. The water quality indices (WQI) suggest that during pre-monsoon, 72.5% samples are suitable for drinking while 86.8% are suitable during post-monsoon. Indicators like sodium absorption ratio (SAR), electrical conductivity (EC), percent of sodium (Na %), residual sodium carbonate (RSC), permeability index (PI), magnesium ratio (MR), residual sodium bicarbonate (RSBC), salinity hazard (SH), potential salinity (PS), soluble sodium percentage (SSP), and magnesium ratio (MR) were estimated for assessing the irrigation suitability of the groundwater samples. Wilcox, United States Salinity Laboratory diagrams (USSL diagram) and Doneen’s chart infer that most of the samples are suitable for irrigation purpose and the suitability improves during post-monsoon. The geochemical evolution of the groundwater was also studied using Piper’s and Chadha’s diagrams. The major facies found in groundwater are Na–Mg–HCO3–Cl, Na–Mg–HCO3, Na–HCO3, Mg–Ca–HCO3, Mg–Na–HCO3 and Na–Cl. Rock-water interaction, ion exchange and evaporite dissolution were found to be the major geochemical processes governing the groundwater chemistry.
Keywords: Water Quality Index; Hydrochemistry; Hard rock aquifers; Drinking and irrigation suitability

The sustainability management of groundwater resource globally is challenged by its vulnerability to pollution resulting from anthropogenic activities. In order to address this problem, the DRASTIC index model (DIM) method among the existing vulnerability modeling techniques is commonly used. OWA-DRASTIC index model (ODIM) technique is another recently developed method for the same task. This study investigated the application of these vulnerability-biased modeling methods in a multi-faceted geologic setting at Perak Province, Malaysia with the view of establishing their efficiencies. The models considered seven pollution potential conditioning factors (PPCFs) obtained from difference data sources. Applying the GIS-based multi-criterial algorithm of these models, the PPCFs were related for developing multi-parameters-based vulnerability index model equations. Groundwater vulnerability to pollution index (GVPI) maps was produced from the synthesized estimated results of the applied multi-parameters-based vulnerability index model equations. The reliability of the produced GVPI maps was established using analyzed groundwater quality data results. The obtained prediction accuracy results for the ODIM-based GVPI map and DIM-based GVPI map are 85.71 and 64.29%, respectively. Besides, the regression coefficient results obtained from the spatially estimate from the DIM and ODIM’ vulnerability index’s values relationship with the pH and manganese concentrations give 83 and 85% for the ODIM technique and 68 and 63% for the DIM technique, respectively. The overall results indicated that the applied ODIM method in the area is a better alternative to the conventional DIM method. The produced GVPI maps can be useful to regional planners and environmental managers entrusted with the protection of groundwater resource.
Keywords: Groundwater vulnerability; ODIM; Physio-chemical parameters; GVPI; DIM

Short-term prediction of groundwater level using improved random forest regression with a combination of random features by Xuanhui Wang; Tailian Liu; Xilai Zheng; Hui Peng; Jia Xin; Bo Zhang (1-12).
To solve the problem where by the available on-site input data are too scarce to predict the level of groundwater, this paper proposes an algorithm to make this prediction called the canonical correlation forest algorithm with a combination of random features. To assess the effectiveness of the proposed algorithm, groundwater levels and meteorological data for the Daguhe River groundwater source field, in Qingdao, China, were used. First, the results of a comparison among three regressors showed that the proposed algorithm is superior in terms of forecasting variations in groundwater level. Second, the results of experiments were used to show the comparative superiority of the proposed method in terms of training time and complexity of parameter optimization. Third, using the proposed algorithm, the highest prediction accuracy was achieved by employing precipitation P(t − 2), temperature T(t), and groundwater level H(t) as the best time lag. This improved random forest regression model yielded higher accuracy in forecasting the variation in groundwater level. The proposed algorithm can also be applied to cases involving low-dimensional data.
Keywords: Groundwater level prediction; Improved random forest regression; Least squares support vector regression; Daguhe River groundwater source field

Study of land use classification in an arid region using multispectral satellite images by Chaitanya B. Pande; Kanak N. Moharir; S. F. R. Khadri; Sanjay Patil (1-11).
Rapid urbanization and deforestation have led to increased areas of wasteland in the northern region of the Akola district of Maharashtra, India. This study investigates land use variations in the arid region with the help of multi-temporal images. Land use maps were employed for analysis of different classes using image classification tools in ArcGIS software. Multispectral satellite imagery data were used to create land cover variation maps and land use forecast maps for the study area. The land use classification change maps were produced from LISS-III satellite images and Landsat Enhanced Thematic Mapper Plus (2008 and 2015) using supervised classification techniques. Land use was divided into five major classes, i.e. agricultural land, developed land, wasteland, water bodies, and forestland. We observed significant changes in agricultural and forestland as a result of many factors including population growth, drought conditions, road infrastructure development, flooding, and soil erosion in the arid area. The overall accuracy of the supervised classification was 94.10% for 2008 and 88.14% for 2015, using the kappa method, which was a satisfactory result. The analysis of land use maps in the arid region revealed different patterns of use between 2008 and 2015. The results of this study may be useful for developing and implementing valuable management strategies for resource protection in the study area. These results show the potential for land use planning and development in arid regions using remote sensing and GIS technology.
Keywords: Land use; Arid region; Satellite images; GIS

Assessments of seasonal groundwater recharge and discharge using environmental stable isotopes at Lower Muda River Basin, Malaysia by Mohd Khairul Nizar Shamsuddin; Wan Nor Azmin Sulaiman; Mohammad Firuz Ramli; Faradiella Mohd Kusin; Kamarudin Samuding (1-12).
An accurate estimation of groundwater recharge is required to properly manage aquifers, especially for riverbank filtration method (RBF) purposes. The isotopes correlations and differences in different water bodies were studied to assess the sources of groundwater recharge and preliminary tools in understanding of the surface water and groundwater interactions in the Lower Muda River Basin. The environmental isotope and hydrochemical sampling results had emphasised that the area near Lower Muda River Basin had a connection with the river and was actively recharging the near-river shallow alluvial aquifer, via RBF method. Furthermore, the shallow groundwater that was close to Muda River from groundwater signatures had indicated the recharge of the shallow aquifer system by Muda River based on the plots along LMWL on a δ2H versus δ18O. The comparisons between like δ2H and δ18O isotopes in the rainwater revealed the variations in the rainfall amount and the 18O-depleted water of those isotopes for wet season precipitation as compared to dry seasons. Furthermore, the groundwater δ2H and δ18O isotopes exhibited a slight deviation from the δ2H and δ18O isotopic meteoric water line in Lower Muda River. Therefore, in this basin, the groundwater could be a combination of river water and precipitation, which had led to the recharge of river water being more than the recharge of rainfall infiltration.
Keywords: Water isotopes; Unsaturated zone; Groundwater recharge; Muda River Basin; Malaysia

Nowadays, technical directors, operative engineers and managers in utility companies often meet with many variants of various types of water supply systems. Such a task is becoming complicated if solar photovoltaic (PV) energy is used as an energy source, due to its stochastic nature. This paper will present the use of the multi-criteria methods PROMETHEE and GAIA for the case of technological criteria. The aim of the paper is finding a technologically most appropriate variant of the observed urban water supply system (UWSS), given that the resulting solution differs according to the size of certain parts. It should be noted that the observed UWSS consists of PV generator and inverter (subsystem PV), pump station (subsystem PS) and water reservoir (subsystem W). In addition, this paper explains the scientifically innovative and applicable methodology for sizing the UWSS driven by PV energy.
Keywords: Water supply; Solar photovoltaic energy; Variant; PROMETHEE; GAIA

The effects of small-scale gold mining activities on heavy metal levels in groundwater were determined for the Lower Pra Basin of Ghana. Sixty five boreholes in 45 communities were analysed between January 2012 and April 2012 for the dry season and June and October 2012 for the wet season. The test for significance and the use of cluster analysis, a multivariate approach, clearly delineate Cu, Zn, Cd and Hg as possible anthropogenic contributors, whilst As, Se and Pb could be both anthropogenic and natural geochemical process contributors of metal level concentrations in the groundwater. The analysis shows generally low pH values in the basin with more than 95% of dry season and almost all wet season values being acidic or slightly acidic. Approximately 35% of boreholes in the wet season recorded values for cadmium above WHO guideline value of 3.0 µg/l with almost all dry season values falling below 3.0 µg/l except for two boreholes. Generally, high values were recorded for iron, manganese, lead, Al and Hg. In general, lead, copper, cadmium and manganese showed higher wet season values than dry season suggesting anthropogenic influence.
Keywords: Anthropogenic; Geochemical; Artisanal; Amalgamation; Cluster

The analysis and prospection using hydrogeochemical methodologies on arsenic (As) contamination episode in region of Spain (Girona, Cataluña) was investigated on the period (2000–2011), to analyze the mechanisms and characteristics of process on the solubilization of As in groundwater and effects of the episode of severe drought (2006–2007) on hydrogeochemical characteristics of the aquifer. The aquifer of study is a Mediterranean Delta; the geology of the zone has influence from sedimentary deposition of Ter River Basin and the prograde and draw back of the history coastline. The aquifer is an alluvial system where mean concentration of (As) is 30 µg/L in groundwater; parallel to this, the concentrations of elements iron (Fe) and manganese (Mn) exceed the guidelines of the World Health Organization (Guidelines for drinking-water quality electronic resource incorporating 1st and 2nd addenda, vol 1, Recommendations, 3rd edn, World Health Organization, Geneva, 2006) for drinking water. Range concentrations from other elements found in the groundwater were: Aluminum (Al, 4–716 µg/L), Barium (Ba, 48–603 µg/L), Cupper (Cu, 0.2–105.3 µg/L), Chrome (Cr, 1.1–47 µg/L) and Nickel (Ni, 1–51 µg/L). The arsenic solubilization trigger mechanism comes from desorption of oxide minerals and reduction related on neutral pH and reductive environment; the source of this kind of oxides is probably from marine sediments deposited in the process of delta’s formation. During the climatic event of drought (2006–2007), the As concentration was responding to decline levels of the water volume on the aquifer, increasing their concentration and localized in a small area of the study zone, and these are effects of the reduction in groundwater flow on the aquifer.
Keywords: Arsenic; Aquifer; Sedimentary basin; Drought

Land use changes around 26 karstic cave–spring systems in Florida were evaluated using geographic information system. Located in the unconfined or semiconfined zones of the Floridan aquifer, some of the cave–spring systems are directly connected to the surficial land use processes by sinking streams, whereas others receiving diffuse recharge are still vulnerable to contamination due to a thin sandy cover overlying the aquifer. Comparison of nitrate-producing land use practices between 2004 and 2013–2014 shows increasing risks of groundwater contamination in the Floridan aquifer. Proliferation of septic systems and wastewater treatment sites due to growing residential areas, increased use of fertilizers for farming and landscaping stand out as major causes of nitrate overload in the both surface and groundwater.
Keywords: Nitrate; Karst; Floridan aquifer; GIS; Groundwater contamination

Regulation of water resources systems using fuzzy logic: a case study of Amaravathi dam by P. V. P. Moorthi; Ajit Pratap Singh; P. Agnivesh (1-11).
Regulation of a water resource system is one of the challenging tasks due to uncertainty involved in demand and supply. It may be due to changes in the climatic conditions, living standards of people, land-use patterns and even because of changes in technology. The problem becomes even more complicated if the objectives pertaining to demand and supply are multiple and conflicting in nature. Therefore, this paper deals with regulation of water resources system based on “if–then” fuzzy logic-based rules which interlinks concepts of interpolative reasoning, logical implications and certain inference tools to infer knowledge about a water resource system using linguistic descriptions. Reasonable inferences have been drawn using concept of tautologies viz. modulus ponens and modulus tollens. Finally, the model is applied to a practical case study in order to demonstrate effectiveness of the proposed logic. The main motive of this study is to demonstrate applicability of fuzzy inference system for regulating operations of water resource systems.
Keywords: Approximate reasoning; Amaravathi dam; Inflow; Outflow; Storage; Reservoir planning; Fuzzy logic; Fuzzy rule-based system: Mamdani and Sugeno methods

Identification of disinfection by-products (DBPs) halo phenols in drinking water by Ramarajan Selvam; Selvakumar Muniraj; Tamilselvi Duraisamy; Vasanthy Muthunarayanan (1-8).
The Bureau of Indian Standard (BIS, New Delhi) has framed a set of standards for drinking water description (IS 10500:1991-http://www.indiawaterportal.org), which has specifications drawn up in 1983 with the most current amendment (July, 2010), and the US Environmental Protection Agency (USEPA 2003) has also developed policy for different drinking water disinfection by-products (DBPs). This study examined the quality of metropolitan drinking water by monitoring the physicochemical parameters, and DBPs study such as the effects of halide ions, natural organic matter, and drinking water characterization were investigated. The sampled water had halo phenols DBPs as a result of disinfection, during chlorination. The water was alkaline in nature, and the water temperature varied from 33 to 37 °C. The major ions, namely bromate, iodate, chlorite, chromate, sulfate and phosphate, have been investigated in the municipality drinking water, Tiruchirappalli and Srirangam in Tamil Nadu, India. Here, three solvents such as hexane, petroleum ether and pentane were used for the liquid–liquid extraction of target compounds. The gas chromatographs equipped with capillary columns (DB-WAX) were employed for the determination of DBPs and 2-bromo-4-chlorophenol was predominantly identified.
Keywords: DBPs; Water; Total organic carbon; Solvents; DB-WAX; GCMS

The Mazar-i-Sharif city is part of the Balkh province, north of Afghanistan, and its groundwater resources are developed for water supply and irrigation purposes. The main lithological units consist chiefly of evaporite, conglomerate, sandstone, siltstone, and loess. In order to evaluate the quality of groundwater in the study area, 28 samples were collected and analyzed for various ions. Chemical indices like sodium adsorption ratio, the percentage of sodium, residual sodium carbonate and permeability index were calculated. Based on the analytical results, groundwater in the area is generally very hard, brackish, high to very high saline, and alkaline in nature. The abundance of the major ions is as follows: Cl > HCO3  > SO4 2− > NO3 and Na+ > Ca2+ > Mg2+ > K+. The dominant hydrochemical facies of groundwater is the Na–Cl type, and alkalis (Na+, K+) and strong acids (Cl, SO4 2−) are slightly dominating over alkali earths (Ca2+, Mg2+) and weak acids (HCO3 , CO3 2−). About 67% of the samples were showing a high concentration of nitrate, exceeding permissible limit of WHO (50 mg/l). The sources of NO3 in the study area are anthropogenic activities (domestic wastewater infiltration from the cesspits) and intense agricultural practices in nearby areas (Balkh district) of the city that utilize nitrogen and sulfate fertilizers. The chemical quality of groundwater is related to the dissolution of minerals, ion exchange, anthropogenic activities, and the residence time of the groundwater in contact with rock materials. The results of calculation saturation index by computer program PHREEQC show that nearly all of the water samples were supersaturated with respect to carbonate minerals (calcite and dolomite) and under-saturated with respect to sulfate minerals (gypsum and anhydrite). Assessment of water samples from various methods indicated that groundwater in the study area is chemically unsuitable for drinking and agricultural uses.
Keywords: Groundwater quality; Mazar-i-Sharif city; Hydrogeochemical processes; Saturation index

Adsorption of chromium (Cr) from tannery wastewater using low-cost spent tea leaves adsorbent by Md. Nur-E-Alam; Md. Abu Sayid Mia; Farid Ahmad; Md. Mafizur Rahman (1-7).
Leather tanning is consuming a large quantity of water and discharging a large volume of wastewater. This wastewater contains the high value of COD, BOD, TSS, TDS and heavy metals. In this study, spent tea leaves, a valueless waste produced during the manufacturing of tea beverage, were assessed for their potential to remove chromium (Cr) from tannery wastewater. Cr removal was studied by the batch process with varying adsorbent dose, contact time and pH of the solution to finding optimum conditions. The experiment results showed that maximum removal of Cr by spent tea leaves was 95.42% at 14 g/L of adsorbent dose and pH 10. The maximum adsorption capacity of Cr on tea waste was found 10.64 mg/g.
Keywords: Tanning; Chromium (Cr); Spent tea leaves; Adsorption; Batch process

Oxygen transfer study and modeling of plunging hollow jets by Munish Kumar; Subodh Ranjan; N. K. Tiwari (1-15).
Experiments were performed to study the effect of jet angle of hollow jet aerators on oxygen transfer of water. Three jet angles of 30°, 45° and 60° were used to produce hollow jets impingement on the water in the pool. Results from experimental study showed a significant effect of hollow jet angle on volumetric oxygen transfer coefficient (K L a) at higher jet velocities. Standard oxygen transfer efficiency (SOTE) of 60° hollow jet aerators is observed higher with low-kinetic-power jets, but at higher kinetic power, 30° hollow jet aerator is observed to be the best in terms of SOTE. Moreover, modeling performance of the experimental data is evaluated by training and testing of the models, and empirical equations derived from multiple linear and multiple nonlinear regression techniques are compared with artificial neural network approach. The results of the present study are also compared with the previous studies of plunging jet aerators.
Keywords: Hollow jet; Volumetric oxygen transfer coefficient; Standard oxygen transfer efficiency; Jet power; Artificial neural network