Electrochemical oxidation of polyethylene glycol in electroplating solution using paraffin composite copper hexacyanoferrate modified (PCCHM) anode.

Electrochemical oxidation of polyethylene glycol (PEG) in an acidic (pH 0.18 to 0.42) and high ionic strength electroplating solution was investigated. The electroplating solution is a major source of wastewater in the printing wiring board industry. A paraffin composite copper hexacyanoferrate modified (PCCHM) electrode was used as the anode and a bare graphite electrode was used as the cathode. The changes in PEG and total organic carbon (TOC) concentrations during the course of the reaction were monitored. The efficiency of the PCCHM anode was compared with bare graphite anode and it was found that the former showed significant electrocatalytic property for PEG and TOC removal. Chlorides present in the solution were found to contribute significantly in the overall organic removal process. Short chain organic compounds like acetic acid, oxalic acid, formic acid and ethylene glycol formed during electrolysis were identified by HPLC method. Anode surface area and applied current density were found to influence the electro-oxidation process, in which the former was found to be dominating. Investigations of the kinetics for the present electrochemical reaction suggested that the two stage first-order kinetic model provides a much better representation of the overall mechanism of the process if compared to the generalized kinetic model.

Impact of some chlorinated pesticides on the haematology of the fish Cyprinus carpio and Puntius ticto.

The effects of pesticides on blood characteristics and histological changes in erythrocytes of the fish species Cyprinus carpio and Puntius ticto were studied. The fishes were exposed to sub lethal concentrations of different chlorinated pesticides namely aldrin, dieldrin, DDT, BHC and chlordane for 10, 20 and 30 d in continuous flow-through test. The LC50 values were calculated based on acute toxicity tests and the sublethal doses were arrived at for chronic bioassay studies. Results showed an increase in haemoglobin content of both Cyprinus carpio and Puntius ticto in case of aldrin and dieldrin. Haemoglobin content reduced from an initial 13 g/100 ml to 8.07 and 10.15 g/100 ml in case of Cyprinus at the end of ten days exposure to aldrin and dieldrin respectively, and gradually increased to 8.7 g/100 ml and 10.15 g/100 ml after 20 d of exposure. The haemoglobin content after 30 d exposure to aldrin and dieldrin was 10.15 g/100 ml and 11.6 g/100 ml respectively. In case of Puntius ticto, the haemoglobin content in control fishes recorded was 12.8 g/100 ml while in case of fish exposed to aldrin, the haemoglobin content reduced initially on ten days exposure to 10.15 g/100 ml and increased to 11.6 g/100 ml and 13.0 g/100 ml during twenty days and thirty days exposure respectively. This trend was also observed with dieldrin in both the fishes studied. Red blood cells were also counted in case of all the pesticides and exposure periods with respect to Cyprinus carpio and Puntius ticto. Irrespective of the species and pesticide, the RBC counts uniformly showed decreasing trend with the increase in exposure period, while packed cell volume, PCV(%) showed increasing trend with respect to increase in exposure period in case of aldrin and dieldrin in both the fishes. But DDT, BHC and chlordane showed decreasing trend in PCV(%) values with increasing periods of exposure.

Development of an evaluation criteria for rural water supply and environmental sanitation programme in project and non-project villages--a case study.

The Rural Water Supply and Sanitation (RWSS) in project and non-project villages of Mysore Taluk has been evaluated and discussed in this paper. The study area covered two villages (Yelwala and Kadakola) where Integrated Water Supply Scheme (IRWSS) was implemented under World Bank Project and two non-project villages (Belwadi and Byathahalli) closer to them. Pre and post scenarios of the project and non-project villages were investigated in terms of water quality analysis and also grading of villages has been done on the basis of water supply, sanitation, hygienic awareness and practices. Matrix methodology was used to evaluate the indicators from the survey data gathered from all studied villages. Finally, the villages were graded on the basis of cumulative value obtained for each village. Water quality analysis depicted turbidity, total dissolved solids and hardness being high and iron deficiency was also observed in water samples of all the villages. It was concluded that the present method of evaluation of rural water supply and sanitation project could be effectively applied to different upcoming projects.

Colour and organic removal of biologically treated coffee curing wastewater by electrochemical oxidation method.

The treatment of biologically treated wastewater of coffee-curing industry by the electrochemical oxidation using steel anode was investigated. Bench-scale experiments were conducted for activated sludge process on raw wastewater and the treated effluents were further treated by electrochemical oxidation method for its colour and organic content removal. The efficiency of the process was determined in terms of removal percentage of COD, BOD and colour during the course of reaction. Several operating parameters like time, pH and current density were examined to ascertain their effects on the treatment efficiency. Steel anode was found to be effective for the COD and colour removal with anode efficiency of 0.118 kgCOD x h(-1) x A(-1) x m(-2) and energy consumption 20.61 kWh x kg(-1) of COD at pH 9. The decrease in pH from 9 to 3 found to increase the anode efficiency from 0.118 kgCOD x h(-1) x A(-1) x m(-2) to 0.144 kWh x kg(-1) of COD while decrease the energy consumption from 20.61 kWh x kg(-1) of COD to 12.86 kWh x kg(-1) of COD. The pH of 5 was considered an ideal from the present treatment process as it avoids the addition of chemicals for neutralization of treated effluents and also economical with respect to energy consumption. An empirical relation developed for relationship between applied current density and COD removal efficiency showed strong predictive capability with coefficient of determination of 96.5%.

Electrochemical treatment of cigarette industry wastewater: feasibility study.

The electrochemical treatability of wastewater from the cigarette industry has been investigated in this paper using cast iron electrode. The treatment efficiency was monitored in terms of COD, BOD and suspended solids concentration. The cast iron anode was found effective in treatment of the above-mentioned wastewater. About 56% of COD and 84% of BOD removal was observed at 3.5 A current for 5 h of electrolysis. The effect of increase in surface area of anode reduces electrolysis time and also energy consumption per kg of COD removal. The treated effluent was subjected to chemical coagulation studies using Ca(OH)2 as coagulant. The final treated effluent was found to confirm the stipulated standards for safe disposal into surface water bodies (Indian Standards). It was concluded that the electrochemical treatment followed by chemical coagulation could be opted as an alternate treatment scheme for the present industry.