工程菌增效/双膜工艺改造农药化工污凝水处理工程实例及运行分析

农药化工废水水质复杂、可生化性差，采用传统生物工艺的处理难度大且效果不理想。针对国内某农药化工废水蒸发后产生的污凝水，采用常规生物处理后，出水化学需氧量（COD）、总氮（TN）及氨氮（NH₃-N）不能达到当地污水处理厂收纳标准的问题，该项目采用外部投加工程菌以提高原生化单元的污水理效能，并增设超滤和反渗透双膜工艺以保障出水水质。改造后的工艺系统调试表明，工程菌增效提升了生化处理单元对污水COD及TN的去除率（分别达到85%与67%），双膜工艺保障处理后，水质ρ（COD）<500 mg/L，ρ（TN）<70 mg/L，ρ（NH₃-N）<45 mg/L]达到下游污水处理厂的收纳标准。经成本核算，该厂污凝水处理项目运行成本为52.77元/t。工程菌增效/双膜工艺改造方案实现了对该厂污水的达标处理排放。

A CASE STUDY AND OPERATION ANALYSIS OF ENGINEERING BACTERIAL AND DUAL-MEMBRANE ENHANCED TREATMENT FOR PESTICIDE WASTEWATER

Owing to the high chemical oxygen demand(COD), organic nitrogen content, and toxicity, the treatment effectiveness of conventional process for pesticide chemical wastewater is relativity low. Treatment of pesticide wastewater becomes a concerned issue in water treatment processes. Aiming at the problems that the condensate wastewater generated by the pesticide wastewater was not properly treated by conventional biological treatment processes, this project proposed a reconstruction scheme by adopting advanced biological treatment process using engineering bacteria synergism and dual-membrane process including ultrafiltration(UF) membrane and reverse osmosis(RO) membrane. After the reconstruction, stable wastewater treatment performance with improved rejection of the COD and TN(with the rejection rate of 85% and 67%, respectively) was observed in the system, and the start-up time of the biochemical system was also shortened. Besides, the dual-membrane process guaranteed the quality of the effluent with COD<500 mg/L, TN<70 mg/L, and NH₃-N<45 mg/L, reaching the standard requirements of the downstream sewage treatment plant. In addition, the total operation cost of the project was 2.77 RMB/ton. The application of the advanced biological treatment process using engineering bacteria synergism, combined with the dual-membrane process guaranteed the efficient treatment of the condensate wastewater from the pesticide chemical plant.