Applied Water Science (v.4, #2)
Geophysical approach to delineate arsenic hot spots in the alluvial aquifers of Bhagalpur district, Bihar (India) in the central Gangetic plains by Pankaj Kumar; Ram Avtar; Alok Kumar; Chander Kumar Singh; Parijat Tripathi; G. Senthil Kumar; A. L. Ramanathan (89-97).
A combined study of the geophysical survey and hydro-geochemistry in the Quaternary alluvial aquifers of Bhagalpur district from Bihar state in central Gangetic plain of India was carried out with the objective of identifying the geochemical processes and their relation with lithological profile. Results of resistivity survey validated with borehole lithology gave us a clear picture of the geological signature of the aquifers, which support the reducing nature of the aquifer where concentration of arsenic was high. Reducing nature of the aquifer environment was shown by water samples having relatively negative Eh value. From XRD study of the soil samples, it was found that goethite, dolomite, calcite, quartz and feldspar are the major minerals for most of the samples. Output of this work concludes that resistivity survey is an economically feasible tool which can be successfully used to target arsenic-safe aquifers on wide scale.
Keywords: Resistivity survey; Hydro-geochemistry; Alluvial aquifers; Gangetic plains; Arsenic
Nitrate contamination of groundwater in two areas of the Cameroon Volcanic Line (Banana Plain and Mount Cameroon area) by Andrew Ako Ako; Gloria Eneke Takem Eyong; Jun Shimada; Katsuaki Koike; Takahiro Hosono; Kimpei Ichiyanagi; Akoachere Richard; Beatrice Ketchemen Tandia; George Elambo Nkeng; Ntankouo Njila Roger (99-113).
Water containing high concentrations of nitrate is unfit for human consumption and, if discharging to freshwater or marine habitats, can contribute to algal blooms and eutrophication. The level of nitrate contamination in groundwater of two densely populated, agro-industrial areas of the Cameroon Volcanic Line (CVL) (Banana Plain and Mount Cameroon area) was evaluated. A total of 100 samples from boreholes, open wells and springs (67 from the Banana Plain; 33 from springs only, in the Mount Cameroon area) were collected in April 2009 and January 2010 and analyzed for chemical constituents, including nitrates. The average groundwater nitrate concentrations for the studied areas are: 17.28 mg/l for the Banana Plain and 2.90 mg/l for the Mount Cameroon area. Overall, groundwaters are relatively free from excessive nitrate contamination, with nitrate concentrations in only 6 % of groundwater resources in the Banana Plain exceeding the maximum admissible concentration for drinking water (50 mg/l). Sources of NO3− in groundwater of this region may be mainly anthropogenic (N-fertilizers, sewerage, animal waste, organic manure, pit latrines, etc.). Multivariate statistical analyses of the hydrochemical data revealed that three factors were responsible for the groundwater chemistry (especially, degree of nitrate contamination): (1) a geogenic factor; (2) nitrate contamination factor; (3) ionic enrichment factor. The impact of anthropogenic activities, especially groundwater nitrate contamination, is more accentuated in the Banana Plain than in the Mount Cameroon area. This study also demonstrates the usefulness of multivariate statistical analysis in groundwater study as a supplementary tool for interpretation of complex hydrochemical data sets.
Keywords: Nitrate contamination; Groundwater; Banana Plain; Mount Cameroon area; Cameroon Volcanic Line
Water quality assessment of carbonate aquifers in southern Latium region, Central Italy: a case study for irrigation and drinking purposes by Giuseppe Sappa; Sibel Ergul; Flavia Ferranti (115-128).
In southern Latium region, Central Italy, groundwater and spring water resources in the carbonate aquifers are the major contributors of drinking and irrigation water supply. The aim of this study was to review hydrochemical processes that control the groundwater chemistry and to determine the suitability of springs and groundwater for irrigation and drinking purposes on the basis of the water quality indices. Physical (pH, electrical conductivity, total dissolved solids) and hydrochemical characteristics (Na+, K+, Ca2+, Mg2+, HCO3−, Cl−, and SO4−) of springs and groundwater were determined. To assess the water quality, chemical parameters like sodium adsorption ratio (SAR), total hardness, Mg-hazard (MH), sodium percentage (Na %), salinity hazard, permeability index, and Kelly’s ratio were calculated based on the analytical results. A Durov diagram plot revealed that the groundwater has been evolved from Ca to HCO3 recharge water, followed by mixing and reverse ion exchange processes, due to the respective dominance of Na–Cl and Ca–Cl water types. According to Gibbs’s diagram plots, chemical weathering of rock forming minerals is the major driving force controlling water chemistry in this area. Groundwater and spring samples were grouped into six categories according to irrigation water quality assessment diagram of US Salinity Laboratory classification and most of the water samples distributed in category C2–S1 and C3–S1 highlighting medium to high salinity hazard and low sodium content class. The results of hydrochemical analyses and the calculated water quality parameters suggest that most of the water samples are suitable for irrigation and drinking purposes, except for the samples influenced by seawater and enhanced water–rock interaction. High values of salinity, Na %, SAR, and MH at certain sites, restrict the suitability for agricultural uses.
Keywords: Carbonate aquifers; Geochemical characteristics; Water quality parameters; Salinity; Water–rock interaction
Hydrochemical study of water collected at a section of the Lower Volta River (Akuse to Sogakope area), Ghana by E. K. Gampson; V. K. Nartey; A. A. Golow; T. T. Akiti (129-143).
The present hydrochemical study at the Lower Volta River (Akuse to Sogakope area), Ghana was conducted by determining the physico-chemical parameters (pH, temperature, total dissolved solute, electrical conductivity, total hardness, phosphate (PO43−), nitrate (NO3−), sulfate (SO42−), dissolve oxygen (DO), biological oxygen demand, calcium (Ca2+), sodium (Na+), magnesium (Mg2+), total iron (Fe), manganese (Mn), copper (Cu) nickel (Ni), and total chromium (Cr) at 38 sampling sites during the wet and the dry seasons. The physical and ionic parameters were mostly found within the WHO (Guidelines for drinking-water quality, 3rd edn, Geneva 2004) standard for drinking water. The trace metals except Cu at some sites recorded values above the WHO (Guidelines for drinking-water quality, 3rd edn, Geneva 2004) standard for drinking water. This shows that the river water is not entirely fit for drinking. Mean values of physico-chemical parameters were mostly found to be high in the dry season as compared to the wet season. Cluster analysis (CA) and principal component analysis (PCA) were employed to evaluate the water quality and the interrelationship between variables. CA grouped the physico-chemical parameters into three groups (physical/minor ions, major ions and trace elements). Correlation analysis showed that physico-chemical parameters do not vary much in terms of the sampling sites. Thus, based on obtained information, it is possible to design a future, desirable sampling strategy, which could reduce the number of sampling stations and associated costs for effective river water quality management. Results showed that four principal components (industrial effect, domestic factor, natural source and agricultural effect) accounted for 65.59 % of the total variance among the water quality parameters. PCA also identified sampling sites 69R, 63R, 51M, 87L, 35L, 74L and 84L as polluted with metals. Therefore, water quality monitoring and control of release of industrial and anthropogenic wastes into the river are strongly needed.
Keywords: Lower Volta River; Physico-chemical parameters; Multivariate analysis; Akuse; Sogakope
Groundwater quality appraisal and its hydrochemical characterization in Ghaziabad (a region of indo-gangetic plain), Uttar Pradesh, India by Uday Veer Singh; Amar Abhishek; Kunwar P. Singh; Ratnakar Dhakate; Netra Pal Singh (145-157).
India’s growing population enhances great pressure on groundwater resources. The Ghaziabad region is located in the northern Indo-Gangetic alluvium plain of India. Increased population and industrial activities make it imperative to appraise the quality of groundwater system to ensure long-term sustainability of resources. A total number of 250 groundwater samples were collected in two different seasons, viz., pre-monsoon and post monsoon and analyzed for major physico-chemical parameters. Broad range and great standard deviation occurs for most parameters, indicating chemical composition of groundwater affected by process, including water–rock interaction and anthropogenic effect. Iron was found as predominant heavy metal in groundwater samples followed by copper and lead. An exceptional high concentration of Chromium was found in some locations. Industrial activities as chrome plating and wood preservative are the key source to metal pollution in Ghaziabad region. On the basis of classification the area water shows normal sulfate, chloride and bi-carbonate type, respectively. Base-exchange indices classified 76 % of the groundwater sources was the sodium-bicarbonate type. The meteoric genesis indices demonstrated that 80 % of groundwater sources belong to a shallow meteoric water percolation type. Chadha’s diagram suggested that the hydro-chemical faces belong to the HCO3− dominant Ca2+–Mg2+ type along with Cl−-dominant Ca2+–Mg2+-type. There was no significant change in pollution parameters in the selected seasons. Comparison of groundwater quality with Indian standards proves that majority of water samples are suitable for irrigation purposes but not for drinking.
Keywords: Groundwater; Base exchange indices; Meteoric genesis indices; Salinity index; Chadda’s diagram; Sodacity index
Identification of surface water-groundwater interaction by hydrogeochemical indicators and assessing its suitability for drinking and irrigational purposes in Chennai, Southern India by K. Brindha; K. V. Neena Vaman; K. Srinivasan; M. Sathis Babu; L. Elango (159-174).
Large cities face water quality and quantity problems due to increasing population and improper disposal of solid and liquid wastes. It is essential to monitor the water quality to take corrective measures. This study was carried out in one of the densely populated metropolitan cities in India to ascertain the suitability of groundwater for drinking and irrigation activity, identify the processes controlling the geochemistry of groundwater and the impact of Adyar River on the groundwater quality. Magnesium and pH concentration in groundwater of this area were within the maximum permissible limits of WHO standards. Sodium and potassium concentration of groundwater were greater than the permissible limit in 30.8 % and in 50 % of the samples, respectively. About 35 % of the groundwater samples were not permissible for drinking based on the electrical conductivity (EC). The EC of groundwater was increasing towards the coast. In general, the quality of groundwater for irrigation purpose vary from moderate to good based on Na%, magnesium hazard, residual sodium carbonate, sodium absorption ratio, permeability index, and USDA classification. Na–Cl and Ca–Mg–Cl were the dominant groundwater and surface water type. Increased ionic concentration of groundwater towards the eastern part of the study area is due to the discharge of industrial effluents and domestic sewage into the Adyar River. Seawater intrusion is also one of the reasons for Na–Cl dominant groundwater near the coast. Evaporation and ion exchange were the major processes controlling groundwater chemistry in this area. The groundwater quality of this region is affected by the contaminated surface water.
Keywords: Geochemistry; Evaporation; Ion exchange; Surface water; Groundwater; Chennai; Adyar River; India
Removal of iron and arsenic (III) from drinking water using iron oxide-coated sand and limestone by Rashmi R. Devi; Iohborlang M. Umlong; Bodhaditya Das; Kusum Borah; Ashim J. Thakur; Prasanta K. Raul; Saumen Banerjee; Lokendra Singh (175-182).
A method for removal of iron and arsenic (III) from contaminated water using iron oxide-coated sand and limestone has been developed for drinking water. For the intended use, sand was coated with ferric chloride and used as filtering media. Limestone was added onto the coated sand and the effect of limestone addition on removal efficiency of iron and arsenic was monitored. Both batch and column experiments were conducted to investigate the efficiency of coated sand and limestone as filtering media. Maximum removal of iron (99.8 %) was obtained with coated sand at a dose of 5 g/100 ml and by adding 0.2 g/100 ml of limestone at pH 7.3. Arsenic (III) removal efficiency increased with the increased dose of coated sand and was best removed at pH 7.12. The maximum adsorption capacity for arsenic (III) obtained from Langmuir model was found to be 0.075 mg/g and the kinetics data followed pseudo-first order better than pseudo-second order. Energy dispersive X-ray analysis and FT-IR study proved the removal of iron and arsenic. Column experiment showed removal of iron and arsenic (III) to <0.3 mg/l and 10 μg/l, respectively, from an initial concentration of 20 mg/l (iron) and 200 μg/l (arsenic).
Keywords: Water; Iron; Arsenic; Coated sand; Limestone
Comparison of the trace metal concentration of drinking water supply options in southwest coastal areas of Bangladesh by Md. Atikul Islam; Md. Rezaul Karim; Takaya Higuchi; Hiroyuki Sakakibara; Masahiko Sekine (183-191).
In the coastal areas of Bangladesh, scarcity of drinking water is acute as the fresh water aquifers at reasonable depths are not available and surface water is highly saline. Households are mainly dependent on rainwater harvesting, pond sand filter (PSF), and rain-fed pond water for drinking purposes. To ascertain the water quality for human consumption, chemical parameters such as pH, conductivity and the concentrations of calcium, magnesium, iron, manganese, copper, zinc, lead, chromium, cadmium, nickel and arsenic were evaluated in the alternative drinking water supply options employed in the southwest coastal areas of Bangladesh. An inductively coupled plasma-optical emission spectroscopy was used for determination of trace metal concentrations. pH and conductivity were measured using HANNA Instrument. The mean iron and manganese concentrations for rain-fed pond and PSF water were much higher than harvested rainwater. The iron concentrations for 41 % of the pond water samples were higher than the Bangladesh guideline value. Iron and manganese removal by PSFs was found to be 74 and 51 %, respectively. Scarcity of calcium and magnesium were found in harvested rainwater. Furthermore, one pond water sample showed arsenic concentration above the 10 μg/l WHO drinking water guideline. The presence of an elevated iron and manganese and low calcium and magnesium concentrations in the drinking water could be a matter of public health concern.
Keywords: Bangladesh; Coastal areas; Drinking water; Trace metal concentrations