Research On Treatment Process Of Clethodim Wastewater

With the sustained and rapid development of China’s economy, concern for the environment has become the consensus of all countries in the world. The most prominent problem of environmental pollution is water contamination. Wastewater from Clethodim production process is especially hard for treatment, with the characteristic of complex composition, high CODcr level, difficult to biological degradation and strong contamination. Therefore, the further research of Clethodim wastewater treatment process has great realistic significance. According to the physicochemical properties of Clethodim wastewater, the ozone oxidation pretreatment-SBR biodegradable co-processing technology is usually used.In the process of ozone oxidation pretreatment of Clethodim wastewater, the ozone oxidation effects are mainly based on three aspects, the ozonation time, the flow rate of the ozone and also the initial pH of wastewater. Our research figured out the optimum conditions:The flow rate of ozone was3.0L/h, wastewater initial pH was8.5and the best ozonation time was2.5h. Under the optimum conditions, the effect of ozone oxidation significantly improved B/C ratio from0.16to0.38, and also reduced the COD level with the removal efficiency more than26%. After the ozone oxidation pretreatment, the Clethodim wastewater is compatible for subsequent biological treatment.The SBR biochemical treatment system was used for the subsequent deep purification of wastewater, our research were focused on the pH of wastewater, hydraulic retention time and phosphorus dosage effects to biochemical efficiency.By means of single factor experiments, the best running conditions of SBR biochemical system were obtained:influent wastewater pH was6.5, the phosphorus dosage was COD:P=800:1and hydraulic retention time was5days. After continuous treatment under the best conditions, the effluent COD of wastewater stabilized at360mg/L, with the removal efficiency up to more than93%.After the ozonation pretreatment and subsequent deep treatment of SBR biochemical system, the final effluent COD reduced from7340mg/L to360mg/L, with the total removal efficiency up to more than95%. The above results show that effect of our wastewater treatment system can meet the standards in Standard for sewage discharged into the city sewer (CJ3082-1999).