Electrospinning production of nanofibrous membranes

Environmental Chemistry Letters - Electrospinning has attracted a worldwide interest as a technique for the production of nanofibrous membranes with diameter ranging 2 nm to several...     

A data-mining approach to predict influent quality

In wastewater treatment plants, predicting influent water quality is important for energy management. The influent water quality is measured by metrics such as carbonaceous biochemical oxygen demand (CBOD), potential of hydrogen, and total suspended solid. In this paper, a data-driven approach for time-ahead prediction of CBOD is presented. Due to limitations in the industrial data acquisition system, CBOD is not recorded at regular time intervals, which causes gaps in the time–series data. Numerous experiments have been performed to approximate the functional relationship between the input and output parameters and thereby fill in the missing CBOD data. Models incorporating seasonality effects are investigated. Four data-mining algorithms—multilayered perceptron, classification and regression tree, multivariate adaptive regression spline, and random forest—are employed to construct prediction models with the maximum prediction horizon of 5 days.     

Acute toxicity of copper sulphate to fresh water prawns

Fresh water prawns, Macrobrachium lamarrei and Macrobrachium dayanum (Crustacea-Decapoda) were subjected to static bioassay tests to ascertain the LC50 values of copper sulphate. The 24, 48, 72 and 96 hr LC50 values of copper sulphate for M. lamarrei were 0.38, 0.361, 0.343 and 0.300 mg/l and for M. dayanum were 1.634, 0.988, 0.532 and 0.418 mg/l respectively. Behavioral responses and LC50 values indicate that M. lamarrei were more sensitive to copper sulphate than M. dayanum.     

Decolorization of structurally different synthetic dyes using cobalt(II)/ascorbic acid/hydrogen peroxide system

The cobalt(II)/ascorbic acid/hydrogen peroxide system was used for decolorization of azo, acridine, anthraquinone, thiazine and triphenylmethane dyes. More than 90% decolorization was obtained with all dyes except Remazol Brilliant Blue R (75%). With other transition metals the system was less efficient. With copper, higher concentration and prolonged incubation time was necessary to obtain the same extent of decolorization. The rate of decolorizaton was not affected by pH in the range of 3-9. The reaction is very fast, with more than 90% decolorization being attained within 15 min. The system produces hydroxyl radicals which are responsible for the decolorization.     

Copper-ligand complex for the decolorization of synthetic dyes

The reaction system containing Cu(II), hydrogen peroxide and D-arabinono-1,4-lactone was found to be effective in the decolorization and reduction of toxicity of azo, thiazine-, triphenylmethane- and anthraquinone-based synthetic dyes. More than 85% decolorization was obtained with 100ppm Acridine Orange, Azure B, Chicago Sky Blue 6B, Crystal Violet, Evans Blue, Poly B-411, Reactive Blue 2, Reactive Blue 5, and Remazol Brilliant Blue R incubated for 24h in the presence of 10mM CuSO(4), 20mM D-arabinono-1,4-lactone and 80 mM H(2)O(2). The rate of decolorization was not affected by pH in the range of 3-9. The rapid decolorization was accompanied by a fast decomposition of H(2)O(2) in the reaction mixture and by a fast production of hydroxyl radicals.     

Gender differences in the metabolism of benzene,toluene and trichloroethylene in rat with special reference to certain biochemical parameters

Metabolites viz. phenol, hippuric acid and total trichloro compounds of benzene, toluene and trichloroethylene respectively were estimated in the urine samples of male and female rats after exposure for a period of 30 days. The results exhibited higher metabolism in female rats than the male rats. Their metabolism might be regulated by cytochrome P450 isozymes in a gender specific manner. However, sex differences in the activity of glutathione-S-transferases of the liver have also been found to determine their toxicity. Results have been discussed with quantitative profiles of other enzymes established in the liver of male and female rats.     

Influence of testosterone on phase-II enzymes in liver and kidney of benzene-treated rats

Testosterone manifests some protective effects against benzene-induced toxicity in rats. However, mechanism of protection remains to be established. Data showed that testosterone modulates conjugation of reactive metabolites of benzene by influencing phase-II enzymes viz. glutathione-S-transferase, glutathione peroxidase, and catalase in both liver and kidney. These observations are supported by the opposite results obtained in castrated rats. It is postulated that testosterone decreases the formation of reactive oxygen species resulting into an increase in phase-II enzymes. Enhanced activity of these antioxidant enzymes is responsible for DNA strand repair as demonstrated by short comet tail length in liver and kidney of benzene and testosterone treated rats. Castration alters benzene pharmacokinetics by influencing these enzymes, a response which may be abolished by testosterone supplementation.