1. Reduction in acute ecotoxicity of paper mill effluent by sequential application of xylanase and laccase.
- Author
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Dhiman SS, Garg G, Sharma J, Kalia VC, Kang YC, and Lee JK
- Subjects
- Aliivibrio fischeri drug effects, Aliivibrio fischeri physiology, Bacterial Proteins isolation & purification, Biological Oxygen Demand Analysis, Coriolaceae chemistry, Coriolaceae enzymology, Endo-1,4-beta Xylanases isolation & purification, Fungal Proteins isolation & purification, Geobacillus stearothermophilus chemistry, Geobacillus stearothermophilus enzymology, Hydrogen Peroxide chemistry, Laccase isolation & purification, Paper, Water Pollutants, Chemical toxicity, Bacterial Proteins chemistry, Endo-1,4-beta Xylanases chemistry, Fungal Proteins chemistry, Industrial Waste, Laccase chemistry, Water Pollutants, Chemical antagonists & inhibitors
- Abstract
In order to reduce the ecotoxicity of paper mill, four different enzymatic pretreatment strategies were investigated in comparison to conventional chemical based processes. In strategy I, xylanase-aided pretreatment of pulp was carried out, and in strategy II, xylanase and laccase-mediator systems were used sequentially. Moreover, to compare the efficiency of Bacillus stearothermophilus xylanase and Ceriporiopsis subvermispora laccase in the reduction of ecotoxicity and pollution, parallel strategies (III and IV) were implemented using commercial enzymes. Conventional C(D)E(OP)D(1)D(2) (C(D), Cl(2) with ClO2; EOP, H2O2 extraction; D1 and D2, ClO2) and X/XLC(D)E(OP)D(1)D(2) (X, xylanase; L, laccase) sequences were employed with non-enzymatic and enzymatic strategies, respectively. Acute toxicity was determined by the extent of inhibition of bioluminescence of Vibrio fischeri with different dilutions of the effluent. Two-fold increase was observed in EC50 values for strategy I compared to the control process. On the other hand, sequential application of commercial enzymes resulted in higher acute toxicity compared to lab enzymes. In comparison to the control process, strategy II was the most efficient and successfully reduced 60.1 and 25.8% of biological oxygen demand (BOD) and color of effluents, respectively. We report for the first time the comparative analysis of the ecotoxicity of industrial effluents.
- Published
- 2014
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