Applied Water Science (v.4, #1)

In this paper, based on the analysis of major ions and rare earth elements (REEs), spring water samples from the north western Bam area, central Iran were investigated for the hydrochemical processes, geochemical behavior of REEs and ion concentration background in the region . In the study area, the order of cation and anion abundance is Na+ > K+ > Mg2+ > Ca2+ and Cl > SO 4 −2  > HCO3 > NO3, and the dominated hydrochemical water are of Na–Cl type. The groundwater shows heavy REEs enrichment relative to light REEs. Depending on water types, REEs show different behaviors in study area. The increase in TDS and Fe contents in groundwater is accompanied by an increase in REE concentrations, while an increase in pH and Eh values is accompanied by a decrease in REE concentrations. Moreover, correlation analysis indicates that Eh–pH condition, TDS and Fe content, aquifer rock as well as their minerals play an important role in controlling the REE enrichment of groundwater.
Keywords: REE; Groundwater; Bam; Hydrogeochemical processes

Ground water quality evaluation near mining area and development of heavy metal pollution index by Bably Prasad; Puja Kumari; Shamima Bano; Shweta Kumari (11-17).
Opencast as well as underground coal mining are likely to disturb the underground water table in terms of quantity as well as quality. Added to this is the problem of leachates from the large number of industrial waste and overburden dumps that are in abundance in mining areas, reaching the ground water and adversely affecting its quality. Enhancement of heavy metals contamination of the ground water is one eventuality. In the present work, concentrations of 7 heavy metals have been evaluated at 20 important ground water sampling stations at Dhanbad township situated very near to Jharia coalfields. The concentration of heavy metals in general was found to be below the permissible levels although concentration of iron and manganese was found above the permissible limits at a few stations. These data have been used for the calculation of heavy metal pollution index (HPI). The HPI of ground water in total was found to be 6.8860 which is far below the critical index limit of 100 pointing to the fact that the ground water is not polluted with respect to heavy metals in spite of the prolific growth of mining and allied industrial activities near the town.
Keywords: Heavy metal pollution index; Ground water; Coal mining; Heavy metals

Due to complex and erratic nature of groundwater occurrences in crystalline basement terrains, groundwater development in form of boreholes/wells without the necessary pre-drilling hydrogeological investigations usually results in failure. Therefore, there is the need for adequate characterization of aquifers and delineation of groundwater potential zones in such crystalline basement setting. This study employed the integration of multi-criteria decision analysis (MCDA), remote sensing (RS) and geographical information system (GIS) techniques to delineate groundwater potential zones in crystalline basement terrain of SW-Nigeria and validation of the result with existing borehole/well yield data. The study approach involved integration of nine different thematic layers (geology, rainfall geomorphology, soil, drainage density, lineament density, landuse, slope and drainage proximity) based on weights assignment and normalization with respect to the relative contribution of the different themes to groundwater occurrence using Saaty’s analytic hierarchy approach. Following weigh normalization and ranking, the thematic maps were integrated using ArcGIS 10.0 software to generate the overall groundwater potential map for the study area. The result revealed that the study area can be categorized into three different groundwater potential zones: high, medium and low. Greater portion of the study area (84,121.8 km2) representing about 78 % of the total area, fall within the medium groundwater potential zone which are generally underlain by medium-porphyritic granite, biotite-hornblende granite and granite gneiss bedrock settings. About 18,239.7 km2 (17 %) fall under high groundwater potential zone which are characterized by weathered/fractured quartzite, quartz-schist, amphibolite schist and phyllite bedrock settings. However, areas of low groundwater potentials constitute only 3 % (3,416.54 km2) of the total study area and are mostly underlain by migmatite, banded and augen gneiss bedrock settings. Subsequent validation with boreholes/well yield data revealed a good correlation with respect to the observed groundwater potential zonation. Wells/boreholes with yields greater than >150 m3/day are generally characteristic of areas with high groundwater potential while those with yields of 75–150 and <75 m3/day are typical of areas with medium and low groundwater potentials, respectively. The validation clearly highlights the efficacy of the integrated MCDA, RS and GIS methods employed in this study as useful modern approach for proper groundwater resources evaluation; providing quick prospective guides for groundwater exploration and exploitation in such crystalline basement settings.
Keywords: Groundwater potential zones; Crystalline basement terrains; Geographical information systems; Remote sensing; Multi-criteria decision analysis

This study aims to discern the domestic gray water (GW) sources that is least polluting, at the urban households of India, by examining the GW characteristics, comparing with literature data, reuse standards and suitable treatment technologies. In view of this, the quantitative and qualitative characteristics of domestic GW originating from bath, wash basin, laundry and kitchen sources are determined and compared with established standards for reuse requirements. Quality of different gray water sources is characterized with respect to the physical, chemical, biological, nutrient, ground element and heavy metal properties. The pollutant loads indicate that the diversion techniques are not suitable for household application and, therefore, treatment is necessary prior to storage and reuse. It is observed that the total volume of GW generated exceeds the reuse requirement for suggested reuse such as for flushing and gardening/irrigation. In spite of generating less volume, the kitchen source is found to be the major contributor for most of the pollutant load and, therefore, not recommended to be considered for treatment. It is concluded that treatment of GW from bathroom source alone is sufficient to meet the onsite reuse requirements and thereby significantly reduce the potable water consumption by 28.5 %. Constructed wetland systems and constructed soil filters are suggested as suitable treatment alternatives owing to its ability to treat highly variable pollutant load with lower operational and maintenance cost, which is more practical for tropical and developing countries.
Keywords: Gray water composition; Gray water treatment; Water treatment technologies; Urban water reuse; Domestic gray water

Prioritizing erosion-prone area through morphometric analysis: an RS and GIS perspective by Sarita Gajbhiye; S. K. Mishra; Ashish Pandey (51-61).
The geomorphological characteristics of a watershed are more commonly used for developing the regional hydrological models for solving various hydrological problems of the ungauged watersheds in inadequate data situations. Therefore, in this study to find out the most vulnerable sub-watershed to soil erosion, morphometric analysis and prioritization were carried out on 14 sub-watersheds of Manot River catchment, which is a tributary of the Narmada River. The morphometric parameters considered for analysis are stream order, stream length, stream frequency, drainage density, texture ratio, form factor, circulatory ratio, elongation ratio, bifurcation ratio and compactness ratio. After analysis of morphometric parameters, compound parameter values are calculated and prioritization rating of 14 sub-watersheds is carried out. The sub-watershed 13 that has the lowest compound parameter value of 3.63 is likely to be subjected to maximum soil erosion; hence, it requires immediate attention to providing soil conservation measures. Morphological parameters-based prioritization is in good agreement with the geological field investigation carried out during the field work.
Keywords: Morphometric analysis; Soil erosion; Prioritization; GIS; Soil conservation

Bacteria-specific uptake rates of three different protozoan taxa on a pure and mixed bacterial community was studied by means of a simplified and functionally reproducible experimental model. The bacterial species Shigella flexneri, Escherichia coli and Salmonella typhi were isolated and classified from stool samples of patients suffering from diarrhea. Paramecium caudatum, Tetrahymena pyriformis and Halteria grandinella, free living ciliate Protozoans, were isolated and identified from Tigris river water. Pure and mixed (E. coli + S. typhi), (E. coli + Sh. flexneri) bacterial cultures were used with each ciliate genera to evaluate the following: predator duplication rate, prey reduction rate, clearance rate and net grazing rate. We used selective lactose fermentation phenomena of enteric bacteria on MacConkey medium for the quantification of bacteria cultural characteristics. The final bacteria concentration was reduced by growing protozoa of 98–99.9 % compared to protozoa-free controls. It showed that Tetrahymena pyriformis had the highest duplication rate (4.13 time/day) in both types of cultures (pure and mixed), followed by Paramecium caudatum and Halteria grandinella, respectively. Paramecium caudatum had the highest rate of ingestion in both types of cultures (26 × 103 bacteria/organism/hr) and yielded the longest time required for 90 % bacterial reduction in a pure suspension of S. typhi (166 h). Clearance rates of pathogenic bacteria by ciliates ranged between 106 nanoliter/organism/h by P. caudatum to S. typhi and 1.92 nanoliter/organism/h seen in T. pyriformis in (E. coli + S. typhi) mixed culture. We used aquatic experimental microcosms under controlled conditions to explore bacteria-dependent ciliate growth and examined whether these ciliates could discriminate between equally sized bacterial preys in a mixture.
Keywords: Ciliates; Enteric bacteria; Clearance rate; Tigris; Bacterivourous

Recent studies in water supply in Enugu urban area have observed that there is a persistent water supply shortage relative to demand. One of the strategies for achieving a good water supply under the circumstance is through efficient water allocation to consumers. The existing allocation system by the Enugu State Water Corporation is not achieving the desired goal, because it is not based on any scientific criteria. In this study, we have employed the linear programming modelling technique to optimise the allocation of 35,000,000 L of water produced daily by the State Water Corporation and supplied to the four sectors of the town. The result shows that the model allocated 27,470,000 L to the residential sector, 3,360,000 L to commercial, 3,120,000 L to industrial and 882,000 L to public institutions sectors leaving a balance of 168,000 L to be utilised in emergency situations. This allocation pattern departs sharply from the present management technique adopted by the corporation. It is then suggested that for urban water supply to be sustainable in the town, the corporation should rely on this technique for water supply.
Keywords: Allocation; Management; Linear programming; Sector; Utilised

Biosorption of carbaryl from aqueous solution onto Pistia stratiotes biomass by Soumya Chattoraj; Naba Kumar Mondal; Biswajit Das; Palas Roy; Bikash Sadhukhan (79-88).
In this work, adsorption of carbaryl from aqueous solution on Pistia stratiotes biomass was investigated. The effects of operating parameters such as initial concentration, pH, adsorbent dose and contact time on the adsorption of carbaryl were analyzed using response surface methodology. The proposed quadratic model for central composite design fitted very well to the experimental data that it could be used to navigate the design space according to analysis of variance results. Response surface plots were used to determine the interaction effects of main factors and optimum conditions of the process. The optimum adsorption conditions were found to be initial carbaryl concentration = 15.57 mg L−1, pH 2.01, adsorbent dose = 0.72 g and contact time = 30 min. The Langmuir, Freundlich and Temkin isotherm models were applied to the equilibrium data. The maximum biosorption capacity of P. stratiotes biomass for carbaryl was found to be 3.1 mg g−1. The pseudo-second-order kinetic model described the carbaryl biosorption process with a good fitting.
Keywords: Adsorption; CarbarylPistia stratiotes biomass; Central composite design