Journal of Water and Environment Technology 

About: Journal of Water and Environment Technology is an academic journal published by Japan Society on Water Environment. The journal publishes majorly in the area(s): Wastewater & Sewage treatment. It has an ISSN identifier of 1348-2165. It is also open access. Over the lifetime, 594 publications have been published receiving 3224 citations.

Biodegradation characteristics of pharmaceutical substances by whole fungal culture Trametes versicolor and its laccase.

Abstract: The degradation of 10 selected pharmaceutically active compounds (PhACs) by whole fungal culture Trametes versicolor, culture filtrates and commercial laccase preparation was conducted. Complete removal of diclofenac (DCF), naproxen (NPX), indomethacin (IDM), ibuprofen (IBP), and fenoprofen (FEP) and partial degradation of other selected PhACs were observed after 48 hours of incubation with the 7-day-old liquid fungal culture both in the presence and absence of ABTS (2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid)) as a laccase-mediator. The catalytic activity of laccase in the degradation of selected PhACs was examined for both crude and commercial extracellular laccase preparations. The results showed that laccase preferentially removed DCF, NPX and IDM among the target PhACs removed by the whole fungal culture. Intracellular enzymes may be involved in the degradation of ketoprofen (KEP), clofibric acid (CA), carbamazepine (CBZ), propyphenazone (PPZ), fenoprofen (FEP) and gemfibrozil (GFZ). The removal of most selected PhACs was increased with the increase in laccase activity. The presence of redox mediators such as ABTS and HBT (1-hyroxybenzotriazole) promoted the degradation of selected PhACs, in which complete removal of DCF, NPX and IDM was observed after 3 hours of incubation with laccase activity (2000 U/L) in the presence of ABTS/HBT. The degradation spectrum by laccase for ionic PhACs with nitrogen-containing structure was quite different from that of the activated sludge process.

Assessment of Trace Metal Contamination in Water and Sediment of Some Rivers in Bangladesh

Abstract: Trace metal contamination is a major problem globally, especially in developing countries. In this study, the levels of trace metals (Cr, Ni, Cu, As, Cd, and Pb) in water and sediment of some peripheral rivers of Dhaka City, Bangladesh, were investigated. Huge amount of municipal wastes, industrial effluents and agricultural runoff from the periphery of Dhaka City notably are dumped to these rivers. Most of the effluents channeled into these rivers are not treated. Sediment and water samples were collected from selected stations along the various rivers in winter and summer seasons and analyzed for the trace metals of concern. Considering the sampling sites, the decreasing order of total metal concentration in water samples were Cr > Cu > As > Ni > Pb > Cd and in sediment were Cr > Pb > Ni > Cu > As > Cd. Total concentrations of Cr, As and Pb in the water samples were higher than WHO guidelines for drinking water quality for some sites. Geoaccumulation index (Igeo) revealed high values of Cd for all the stations. The extent of metal pollution in the rivers around Dhaka City implied that the condition is much frightening and probably severely affecting the aquatic ecology of the rivers.

State of the Art of UV/Chlorine Advanced Oxidation Processes: Their Mechanism, Byproducts Formation, Process Variation, and Applications

Abstract: The photolysis of chlorine by ultraviolet radiation (UV/chlorine) produces HO ̇ and Cl ,̇ part of which further transforms into reactive chlorine species (RCS) like Cl2 −̇ and ClO .̇ These radicals are responsible for the advanced oxidation effect of UV/chlorine processes. Recently, UV/chlorine processes gather much attention from researchers and practitioners and published papers on UV/chlorine processes have drastically increased, which were thoroughly reviewed in this paper for understanding the state of the art of these technologies. Fundamental studies elucidate that acidic conditions are favorable to UV/chlorine processes through a change in quantum yield of chlorine photolysis, equilibrium shifts of radical species, and a change in radical scavenger effect of free chlorine. Comparative studies reveal that UV/chlorine processes are usually more energy-efficient than UV/hydrogen peroxide and UV/ persulfate processes. Although unfavorable byproducts formation by RCS reactions is apprehended, application researches in real waters show that UV/chlorine processes do not enhance disinfection byproducts formation very much. Since UV irradiation and chlorination are widely used unit operations, a barrier to install an UV/chlorine process into a conventional process is not high. It is desired to develop and optimize a whole process combined with other unit processes for maximizing benefits in water treatment in the future.

Direct treatment of polluted river water by the multi-soil-layering method

Abstract: Six Multi-Soil-Layering systems with combinations of two type of soils, Andisol (volcanic ash soil) and Entisol (granitic sandy soil), two particle size classes of zeolite, 1-3 and 3-5mm in diameter, and various hydraulic loading rates, 1 to 4 m3 m-2 day-1, were constructed and were compared for polluted river water treatment. Removal rates of BOD, T-N and T-P were 72.2 to 83.5 %, 22.4 to 50.5 %, and 51.9 to 66.8 %, respectively. Entisol was more efficient for T-N and T-P removal than Andisol. Zeolite of 1-3mm in diameter was more efficient for removal of all the pollutants than that of 3-5mm. These materials might contribute more effective contact of inlet water to the various components for purification in the MSL systems. Lower loading rate was more efficient for BOD and T-N removal. The loading rate of 2 m3 m-2 day-1 was the most efficient for T-P removal. However, differences in removal rates of these pollutants of river water among the MSL systems were small considering with the differences of hydraulic loading rates. The difference in BOD removal rates between MSL 1 and 6 was only 10 % against to 400 % difference in the loading rates between them. Although clogging was observed at the loading rate of 4 m3 m-2 day-1, the system was recovered after 2 months rest. These results indicated that higher loading rate, 4 m3 m-2 day-1, was more advantageous and practical for direct river water treatment.