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Increasing demand for water from agriculture, industrial and domestic sectors, resulted in stress on the water resources both from quantity and quality perspectives. Due to urbanization many of the dyeing units have shifted from urban to nearby rural areas. Here safe disposal of untreated effluent from the dyeing units is a challenge and is often let into nearby water bodies. Pandravedu Lake, located in Thiruvallur district of Tamil Nadu, India is one such case were the present study is carried out. Water samples were collected from twelve locations during pre-monsoon, monsoon and post-monsoon seasons, in pre-cleaned polyethylene cans and analyzed for physico-chemical parameters like pH, total dissolved solids, electrical conductivity, total alkalinity, total hardness, calcium, magnesium, sodium, potassium, iron, nitrate, chloride, fluoride and sulphate following the standard analytical procedures recommended by American Public Health Association (2005).The analytical results indicated that 40% to 70% of samples exceeded the drinking water quality standards prescribed by Bureau of Indian standards (BIS, 2012). Water quality index computed indicate that both the bore wells that supply drinking water to the village falls in very poor category (101 – 150) across three seasons. Correlation analysis indicated that seasonal changes in correlation among the parameters are linked to the fluctuations of wastewater discharge and its characteristics.

Biodegradation has become a popular alternative remediation technology due to its economical and ecological advantages. A strain able to degrade o-xylene effectively was selected and identified as Zoogloearesiniphila HJ1. The organism, strain HJ1, could degrade o-xylene with concentration as high as 256 mg L–1 at pH 6.8 and 26.3 °C. The Haldane model adequately described the relationship between specific growth rate and substrate concentration. The maximum specific growth rate and yield coefficient were 0.118 h-1 and 0.2572, respectively. A high mineralization rate of 67.9% was observed. Theenzyme activity and metabolic intermediates analysis showed that the ring cleavage of o-xylene was catalyzed by catechol 1,2-dioxygenase, and 3,4-dimethylcatechol was the main metabolic product. The present study demonstrated that the isolated strain, Zoogloearesiniphila HJ1, had a great application prospect for remediation of o-xylene-contaminated environment.

The production and use of biofuels such as ethanol have been the target of intensive research. One source of ethanol is corn, which is abundant in many countries. In producing ethanol from corn, an assessment of the environmental impact of the process is needed. This study intends to provide insight into benzene emitted from a proposed biofuel plant, its dispersion behavior, and the effects it may have on the immediate environment. Three-season (January, April, and June) dispersion results of benzene emissions from the proposed ethanol-producing facility are evaluated by using the CALPUFF modelling system. Within the framework of the CALPro software, ambient benzene concentrations are modelled over a 24-hour period of exposure by considering the impact of pollutant transformation and removal, and meteorological factors such as wind direction and speed, and temperature. Simulations are performed for the plant area located in Farewell, Oshawa, Ontario, based on the emission and meteorological dataset for the year 2013. The modeling domain covers the area of 30 × 30 km2 with the grid spacing of 150 m. The number of grid lines is taken as 200 for each axis, and the dispersion of benzene emissions is simulated in nine vertical layers of the domain of study. Based on simulated one-hour and 24-hour average benzene concentrations, pollution dispersion results show that the maximum concentrations are recorded as 4.585 and 0.403 µg/m3 at 17h00 LST on hourly basis and on 24-hour basis, respectively, for the winter season. For the spring season, the highest concentrations are measured as 1.345 and 0.136 µg/m3 at 21h00 LST for one-hour and 24-hour periods, respectively. For the summer season, the peak benzene concentrations are found to be 1.085 and 0.277 µg/m3 at 01h00 LST. The results indicate that none of the months exceeds the half-hour limit of 7 µg/m3 set by Ontario Regulation 419/05, but they surpass the Ontario Regulation 419 Schedule 3 limit of 0.01 µg/m3 for a 24-hour dispersion period. This information may prove invaluable to further research on the impacts of the ethanol-production process on the environment.

In this study, potential of okra leaves for the removal of Ni(II), Cu(II), Pb(II) and Cd(II) from the mixed metal aqueous solution were evaluated. The data were analyzed by Freundlich, Langmuir, D-R, Flory-Huggins and Halsey adsorption models. Pseudo first order rate, Pseudo second order rate, Morris-Weber and Elovich equations were employed to understand the kinetics of the reaction. The characterization of the adsorbent was carried out by EDX and FTIR techniques. The order of maximum metal uptake calculated by D-R isotherm was Cu(II) > Pb(II) > Cd(II) and Ni(II), 453 mg g-1, 81 mg g-1, 13.82 mg g-1 and 1 mg g-1 respectively, with the energy of adsorption in the range of 9-15 for Ni(II) and Cd(II) expected for the ion exchange nature of adsorption and 7-8 for Cu(II) and Pb(II) showing the physical nature of adsorption. The calculated thermodynamic parameters like Gibbs free energy and enthalpy change demonstrate that adsorption process was spontaneous and endothermic in nature. Further it was observed that all four metal ions could be adsorbed at pH 6 with detection limits of 0.04-0.1 µg L-1. The method was successfully applied for the removal of these metal ions from the ground water, tap water and wastewater samples collected from different areas of Pakistan.