Applied Water Science (v.2, #3)

Insights into Mejerda basin hydrogeology, Tunisia by Rihab Guellala; Mohamed Ali Tagorti; Mohamed Hédi Inoubli; Faouzi Amri (143-155).
The present study concentrates on the interpretation of Vertical Electrical Soundings (VES) and well logs to understand the geometry and the functioning of the Ghardimaou multilayered aquifer, a potential target for water supply in the Mejerda basin (Tunisia). The analysis of isobath and isopach maps established in this study, shows a tectonic influence on the reservoirs structure; the Villafranchian folding and the NE–SW, and E–W normal faulting in the recent Quaternary created an aquifer system compartmentalized by raised and tilted blocks. Geoelectrical cross sections reveal that this structure influences the thickness of permeable formations and the groundwater circulation. These results will be useful for rationalizing the future hydrogeological research that will be undertaken in the Mejerda basin.
Keywords: Vertical electrical sounding; Well logging; Compartmentalized aquifer; Tunisia

This study was done on 30 drinking tap water samples (surface and ground) and 30 urine samples taken from patients who attended some of Dakahlyia governorate hospitals. These patients were complaining of poor-quality tap water in their houses, which was confirmed by this study that drinking water is contaminated with trace elements in some of the studied areas. The aim of this study was to determine the relationship between the contaminant drinking water (surface and ground) in Dakahlyia governorate and its impact on human health. This study reports the relationship between nickel and hair loss, obviously shown in water and urine samples. Renal failure cases were related to lead and cadmium contaminated drinking water, where compatibilities in results of water and urine samples were observed. Also, liver cirrhosis cases were related to iron-contaminated drinking water. Studies of these diseases suggest that abnormal incidence in specific areas is related to industrial wastes and agricultural activities that have released hazardous and toxic materials in the drinking water and thereby led to its contamination in these areas. We conclude that trace elements should be removed from drinking water for human safety.
Keywords: Water samples; Urine samples; Trace elements

Evaluation of groundwater quality and its suitability for drinking and agricultural use in the coastal stretch of Alappuzha District, Kerala, India by S. V. Sarath Prasanth; N. S. Magesh; K. V. Jitheshlal; N. Chandrasekar; K. Gangadhar (165-175).
Groundwater is an essential and vital component of any life support system. It is not only the basic need for human existence but also a vital input for all development activities. The present hydro-geochemical study was confined to the coastal belt of Alappuzha district, which lies in the coastal lowland division of Kerala. Groundwater quality and its suitability for irrigation and domestic purpose were examined by various physico-chemical parameters such as pH, electrical conductivity, total dissolved solids, total hardness, calcium, magnesium, sodium, potassium, bicarbonate, sulfate, and chloride. These parameters were used to assess the suitability of groundwater for domestic purpose by comparing with the WHO and Indian standards. TDS, sodium adsorption ratio (SAR), and permeability index were used for irrigation suitability assessment. The sample analysis reveals that the groundwater is not entirely fit for drinking with respect to pH, EC, Ca2+, Mg2+, Na+, and Cl. In some of the collected samples, the concentrations of these parameters exceed the permissible limits of WHO and ISI standards. Based on TDS and SAR almost all samples are suitable for irrigation purpose except a few locations, which show values beyond the permissible limits. Ca–Mg–HCO3 is the dominant water type in the study area. The sequence of the abundance of the major cations and anions is Ca > Na > Mg > K = HCO3 > Cl > SO4. Based on the total hardness and TDS, 96 % of groundwater samples are found suitable for drinking purpose.
Keywords: Groundwater quality; Hydrochemical facies; SAR; Permeability index; GIS; Kerala

The present article represents synthesis and As(III) sorption behavior of a novel calix[4]arene-appended functional material (DE-4 resin). The sorption ability of DE-4 resin has been evaluated at wide range of pH, i.e., pH 2–14. It has been observed that the DE-4 resin possesses greater interaction for As(III) with maximum sorption capacity (88 % at pH 4). Column sorption mechanism was studied through various parameters, i.e., change in concentration, flow rate, and bed heights. The results obtained by changing these parameters were compared with the theoretically calculated. From the results it has been observed that DE-4 resin has maximum column efficiency of 412 μg g−1. Thermal behavior of the synthesized DE-4 resin was examined at various temperatures from 298 to 338 K, which shows that column efficiency increases with increase in temperature. From the DSC study it has been observed that DE-4 resin is stable up to 439 K. Concerning regeneration ability DE-4 resin was found to be regenerable and best regeneration was achieved using 5 % solution of HNO3/NaOH. It can be deduced from the study that the resin will find its applicability in small as well as industrial-scale water purification plants.
Keywords: Calix[4]arene; Arsenite sorption; BDST model; Solid-phase extraction; Breakthrough curve

Kinetics and equilibrium studies for the removal of heavy metals in both single and binary systems using hydroxyapatite by S. T. Ramesh; N. Rameshbabu; R. Gandhimathi; P. V. Nidheesh; M. Srikanth Kumar (187-197).
Removal of heavy metals is very important with respect to environmental considerations. This study investigated the sorption of copper (Cu) and zinc (Zn) in single and binary aqueous systems onto laboratory prepared hydroxyapatite (HA) surfaces. Batch experiments were carried out using synthetic HA at 30 °C. Parameters that influence the adsorption such as contact time, adsorbent dosage and pH of solution were investigated. The maximum adsorption was found at contact time of 12 and 9 h, HA dosage of 0.4 and 0.7 g/l and pH of 6 and 8 for Cu and Zn, respectively, in single system. Adsorption kinetics data were analyzed using the pseudofirst-, pseudosecond-order and intraparticle diffusion models. The results indicated that the adsorption kinetic data were best described by pseudosecond-order model. Langmuir and Freundlich isotherm models were applied to analyze adsorption data, and Langmuir isotherm was found to be applicable to this adsorption system, in terms of relatively high regression values. The removal capacity of HA was found to be 125 mg of Cu/g, 30.3 mg of Zn/g in single system and 50 mg of Cu/g, 15.16 mg of Zn/g in binary system. The results indicated that the HA used in this work proved to be effective material for removing Cu and Zn from aqueous solutions.
Keywords: Hydroxyapatite; Adsorption; Isotherm; Kinetics

Performance and characterization of a new tannin-based coagulant by J. Beltrán-Heredia; J. Sánchez-Martín; C. Gómez-Muñoz (199-208).
Diethanolamine and formaldehyde were employed to cationize tannins from black wattle. This novel coagulant called CDF was functionally characterized in removing sodium dodecylbenzene sulfonate (anionic surfactant) and Palatine Fast Black WAN (azoic dye). Refined tannin-derived commercial coagulants exhibited similar efficiency, while CDF presented higher coagulant ability than alum, a usual coagulant agent. Low doses of CDF (ca. 100 mg L−1) were able to remove more than 70 % of surfactant and more than 85 % of dye (initial pollutant concentration of ca. 100 mg L−1) and it presented no temperature affection and worked at a relatively wide pH range. Surfactant and dye removal responded to the classical coagulant-and-adsorption models, such as Frumkin–Fowler–Guggenheim or Gu and Zhu in the case of surfactant, and Langmuir and Freundlich in the case of dye.
Keywords: Tannins; Coagulation; Natural coagulants; Dye removal

Biosorption potential of hen feathers (HFs) to remove methylene blue (MB) from aqueous solutions was investigated. Batch experiments were carried out as function of different process parameters such as pH, initial dye concentration, biosorbent dose and temperature. The optimum conditions for removal of MB were found to be pH 7.0, biosorbent dose = 1.0 g, and initial dye concentration = 50 mg L−1. The temperature had a strong influence on the biosorption process. Experimental biosorption data were modeled by Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherms with the Langmuir isotherm showing the best fit at all temperatures studied. The maximum monolayer sorption capacity was determined as 134.76 mg g−1 at 303 K. According to the mean free energy values of sorption (E) calculated using the D–R isotherm model, biosorption of MB onto HFs was chemisorption. Kinetic studies showed that the biosorption of MB followed pseudo second-order kinetics. The activation energy (Ea) determined using the Arrhenius equation confirmed that the biosorption involved chemical ion-exchange. Thermodynamic studies showed that the biosorption process was spontaneous and exothermic. To conclude, HFs is a promising biosorbent for MB removal from aqueous solutions.
Keywords: Biosorption; Hen feathers; Methylene blue; Equilibrium; Kinetics; Thermodynamics

Energy pattern analysis of a wastewater treatment plant by Pratima Singh; Cynthia Carliell-Marquet; Arun Kansal (221-226).
Various forms of energy are used during a wastewater treatment process like electrical, manual, fuel, chemical etc. Most of the earlier studies have focused only on electrical energy intensity of large-scale centralized wastewater treatment plants (WWTPs). This paper presents a methodological framework for analysing manual, mechanical, chemical and electrical energy consumption in a small-scaled WWTP. The methodology has been demonstrated on a small-scale WWTP in an institutional area. Total energy intensity of the plant is 1.046 kWh/m3 of wastewater treated. Electrical energy is only about half of the total energy consumption. Manual energy also has a significant share, which means that the small-scale treatment plants offer significant employment opportunities in newly industrializing countries and replaces fossil fuel-based energy with renewable. There is a lack of sufficient data in the literature for comparison, and few studies have reported values that vary significantly due to the difference in scale, scope of the study and the choice of the treatment technologies. Replication of similar studies and generation of data in this area will offer directions for decision on choice of the scale of wastewater treatment process from the considerations of energy and climate change mitigation strategies.
Keywords: Energy pattern analyses; Wastewater treatment; Methodological framework; Energy intensity

Modern hydrological status of the estuary of Ili River by Zhakupbay Dostay; Sayat Alimkulov; Aisulu Tursunova; Akhan Myrzakhmetov (227-233).
The study addresses the problems and the history of formation and functioning of one of the largest intracontinental estuaries in Kazakhstan—the Ili River waterway. Being a natural regulator of the ecological status of the region, the estuary of Ili River also influences the water regime of Lake Balkhash. This work studied the current state of hydrographic and hydrological networks in a selected area and the distribution of water flow entering the estuary through the various ducts. Using a water balance method, this study calculated the loss of water in the delta, estimated runoff to the peak of delta and the inflow of river water into Lake Balkhash for two periods: the natural-conditioned and disturbed. As a result of the work performed, it was possible to trace the dynamics of hydraulic parameters for a multiyear period.
Keywords: Estuary; River delta; Ecosystem; River basin; River flow; Water resources; Channel; Waterway; Lake; Hydrological regime; Water volume; Peak of delta; Flow losses; Water line