Research On Treatment Of Clomazone And Pretilachlor Wastewater With Microelectrolysis Method

Because of the characteristics such as large flow quantity, high concentration organic, color, toxic, debiodegradation, and so on, pesticides wastewaters would pollute environment severesly if discharged straightly without being treated. Various factors were researched on Clomazone and Pretilachlor produced wastewater by micro-electrolysis method in this dissertation. The feasibility of pre-treating of these pesticide wastewaters had been proved from the experiments.During the static experiment, the factors of pH values, reaction time, blowing air volume and ratio of weigh of the iron to carbon had been studied separately. When the volume of treated water was 1L, the optimal conditions were the ratio of weigh of the iron to carbon 4.5:1, the pH value of the solution was 2, the reaction time was 4h, and the blowing air volume was 0.25m³/h. The quantity of H₂O₂ could influence the removal efficiency of micro-electrolysis, the optimum quantity of H₂O₂ was 2% of treatment quantity in the static experiment and that was 1% in the continuous experiment. The two methods of micro-electrolysis and Fenton's reagent formed by adding H₂O₂ after micro-electrolysis could show the considerable removal efficiency in different concentrations of wastewater. The highest removal rate of COD of microelectrolysis was 63%, and the highest treating effect of Fenton formed by adding H₂O₂ was 72.3%. The biodegradability of wastewater was improved after microelectrolysis-peroxide pretreatment. When the concentration of wastewater was 6000～7000mg/L, the BOD₅/COD value was increased 47%, from 0.28 to 0.47. When the concentration of wastewater was 44890～56100mg/L, the BOD₅/COD value was increased from 0.39 to 0.47, about 20% higher.During the continuous experiment, the microelectrolysis reactor could stablely run 40 days continuously. The removal efficiency of COD was over 35% in microelectrolysis reaction, which was over 45% in Fenton formed by adding H₂O₂. The decline in the concentration of organic substance was monitored by HPLC. It is indicated that the method of microelectrolysis could open and break the annulation of pesticide wastewater and the method of Fenton's reagent could effectively remove Clomazone.