Evaluating the groundwater potential of Wadi Al-Jizi,Sultanate of Oman,by integrating remote sensing and GIS techniques

Environmental Science and Pollution Research - Groundwater resources are highly stressed due to their overuse, especially in the arid region. This study is aimed at discovering potential...     

Assessment of water quality of Manchar Lake in Sindh (Pakistan)

Manchar Lake is the largest natural freshwater lake in Pakistan. The Lake has received less fresh water in past few years. In addition, drainage water is being discharged in the Lake through Main Nara Valley Drain (MNVD) since many years. Consequently, concern has grown regarding the water quality of the Lake. The aim of this study was to assess the water quality of Manchar Lake and MNVD and the objectives were to determine physiochemical properties and the concentrations of common cations and anions as well as seven trace metals i.e. Cu, Ni, Zn, Co, Fe, Pb and Cd. The concentration of the trace metals were determined by simultaneous preconcentration and solvent extraction using flame atomic absorption spectrometer. Results of physicochemical parameters of Manchar Lake water samples showed mean pH 8.4 (±0.2), conductivity 2,310.3 (±581.3) μS cm⁻¹ and hardness (as CaCO₃) 213.1 (±62.3) mg l⁻¹. Mean concentrations of cations and anions were Na 521.5 (±49.7), Cl⁻ 413.6 (±225.7), Ca 70.7 (±12.9), Mg 56.2 (±28.9), K 17.6 (±6.5), 0.34 (±0.2) and 0.02 (±0.01) mg l⁻¹. Mean concentrations of trace metals were Zn 15.7 (±1), Fe 12 (±3.5), Pb 9 (±2.7), Cu 8.9 (±7.7), Ni 4.3 (±3.4), Co 4 (±3.4) and Cd 1.1 (±1) μg l⁻¹. MNVD water samples showed mean pH 8.9 (±0.8), conductivity 1,735.7 (±567.8) μS cm⁻¹ and hardness (as CaCO₃) 184.8 (±32.4) mg l⁻¹. In MNWD, the mean concentrations of cations and anions were Na 482.7 (±11.7), Cl⁻ 395.7 (±271.5), Ca 79.1 (±23.5), Mg 54.2 (±28.1), K 26.2 (±21.3), NO⁻³ 0.5 (±0.3) and 0.1 (±0.1) mg l⁻¹. Mean concentrations of trace metals observed in MNWD water were Fe 14.9(±3.5), Cd 8.3 (±9.4), Pb 6.9 (±2.4), Cu 6.6 (±3.1), Zn 6.2 (±1.8), Co 4.5 (±2.7), and Ni 3.5 (±2.9) μg l⁻¹. The pH of both Manchar Lake and MNVD waters and concentration of Pb in Manchar Lake and concentration of Cd in MNVD water were higher than the World Health Organisation’s guideline values for the drinking water quality. The water quality of Manchar Lake was found degraded.     

Utility of cefixime as a complexing reagent for the determination of Ni(II) in synthetic mixture and water samples

A simple, sensitive, and accurate UV spectrophotometric method has been developed for the determination of nickel in synthetic mixture and water samples. The method is based on the complexation reaction of nickel ion with cefixime, thus leading to the formation of Ni–cefixime complex in ethanol-distilled water medium at room temperature. The complex showed the maximum absorption wavelength at 332 nm. Beer’s law is obeyed in the working concentration range of 0.447–4.019 μg?mL^?1 with apparent molar absorptivity of 7.314?×?10³?L?mol^?1?cm^?1 and Sandell’s sensitivity of 0.008 μg/cm²/0.001 absorbance unit. The limits of detection and quantitation for the proposed method are 0.016 and 0.054 μg?mL^?1, respectively. The factors such as cefixime concentration and solvent affecting the complexation reaction were carefully studied and optimized. The method is validated as per the International Conference on Harmonisation guideline. The method is successfully applied to the determination of Ni(II) in synthetic mixture and wadi water samples collected from Al Rustaq. The same water samples are also analyzed by atomic absorption spectrophotometry. Both methods determined the amount of Ni(II) in water sample and found to be approximately the same.     

Effects of fertilization on phosphorus distribution in water-stable aggregates of soils with different properties

Aggregation in agricultural soils is considered as an important physical process affected by fertilizers or manure addition. Therefore, the effects of two fertilizers, mineral and manure were assessed using three soils and correlate the soil properties on phosphorus distribution in water-stable aggregate (WSA). Application of manure increased the proportion of WSA (>5 mm) in all soil types, and mineral fertilizer (MF) slightly increased the proportion of microaggregates in entisols and isohumosols. Both fertilizers increased total phosphorus in all WSA sizes, and the highest values were observed in those of ferrosols and isohumosols. In entisols, the highest total phosphorus value was found in microaggregates in water-soluble form. Manure enhanced the organic phosphorus in all soil types, and MF resulted in enrichment of organic phosphorus in WSA (<2 mm) of entisols.     

Impact of green supply chain management practices on firms’ performance: an empirical study from the perspective of Pakistan

Environmental Science and Pollution Research - This article investigates the impact of five determinants of the green supply chain practices on organizational performance in the context of Pakistan...     

Low cost sorbents for the removal of methyl parathion pesticide from aqueous solutions

Sorptive potential of selected agricultural waste materials i.e. rice (Oryza sativa) bran (RB), bagasse fly ash (BFA) of sugarcane (Saccharum officinarum), Moringa oleifera pods (MOP) and rice husk (RH) for the removal of methyl parathion pesticide (MP) from surface and ground waters has been investigated. Optimization of operating parameters of sorption process, i.e. sorbent dose, agitation time, pH, initial concentration of sorbate, and temperature have been studied. The sorption data fitted to Freundlich, Langmuir and Dubinin-Radushkevich (D-R) sorption isotherms. The maximum capacities of RB, BFA, MOP and RH for MP were calculated to be 3.6+/-0.8, 5.3+/-1.4, 5.2+/-1.5 and 4.7+/-1.0 mmolg(-1) by Freundlich, 0.39+/-0.009, 0.39+/-0.005, 0.36+/-0.004 and 0.35+/-0.008 mmolg(-1) by Langmuir and 0.9+/-0.08, 1.0+/-0.10, 1.0+/-0.10 and 0.9+/-0.07 mmolg(-1) by D-R isotherms respectively, employing 0.1g of each sorbent, at pH 6, 90 min agitation time and at 303 K. Application of first order Lagergren and Morris-Weber equations to the kinetic data yielded correlation coefficients, close to unity. Thermodynamic parameters of sorption process, i.e. DeltaH, DeltaS and DeltaG were computed and their negative values indicated the exothermic and spontaneous nature of sorption process. The pesticide may be stripped by sonication with methanol, making the regeneration and reutilization of sorbents promising. The sorbents investigated exhibited their potential applications in water decontamination, treatment of industrial and agricultural waste waters.     

Biological activity and bioavailability of grain bound 14C-malathion residues in rats.

Paddy (unmilled rice), milled rice and maize-bound 14C residues were prepared using 14C-succinate-labelled malathion at 10 and 152 ppm. After 3 months, the bound residues accounted for 12%, 6.5% and 17.7% of the applied dose in paddy, milled rice and maize respectively in the grains treated at 10 ppm. The corresponding values for the 152 ppm were 16.6%, 8.5% and 18.8%. Rats fed milled rice - bound 14C-residues eliminated 61% of the 14C in the faeces and 28% in the urine. The corresponding percentages for paddy and maize were 72%, 9% and 53%, 41% respectively; indicating that bound residues from milled rice and maize were moderately bioavailable. When rice-bound malathion residues (0.65 ppm in feed) were administered to rats in a 5 week feeding study, no signs of toxicity were observed. Plasma and RBC cholinesterase activities were slightly inhibited: blood urea nitrogen was significantly elevated in the test animals. Other parameters examined showed no or marginal changes.     

Social and economic considerations in conserving wetlands of indo-gangetic plains: A case study of Kabartal wetland,India

The Kabartal wetland situated in the upper Indo-Gangetic flood plains in northern India is significant because of its hydrological and ecological services, and the socio-economic and cultural values that it represents. Despite being designated as a wildlife sanctuary, this wetland is under threat from anthropogenic pressures. As in the case of most wetlands, the reason is incomplete information on its ecological services and functions, breakdown of traditional management structures and the lack of appropriate and recognized property rights. Our study assesses the economic linkages between the Kabartal wetland and the local people living around it, through socio-economic surveys and Contingent Valuation Method (CVM). The major objective of the study was to determine the importance of this wetland to the local people and to give an indication of the distribution of the benefits among various stakeholders. The people in the region are poor, have low literacy levels and high dependence on Kabartal and more than 50% want that the wetland should be drained and the land used for agriculture. However, they are willing to participate in collaborative management initiatives with the state. The willingness of people to accept compensation, as an alternative to access to Kabartal wetland, regressed on various socio-economic and attitudinal parameters, gave an estimated mean value of US $27,500 per household over a period of 60 years. This value is a pointer of the total value of access to Kabartal wetland to the surrounding villagers and would be useful when decisions to compensate people for lost access to Kabartal are made.