微气泡臭氧催化氧化-生化耦合工艺深度处理煤化工废水

采用微气泡臭氧催化氧化-生化耦合工艺对煤化工废水生化出水进行深度处理,考察耦合系统处理性能及不同臭氧投加量和进水COD量比值的影响.结果表明,微气泡臭氧催化氧化处理能够有效降解废水中难降解含氮芳香族污染物,去除部分COD并释放氨氮,显著提高废水可生化性,臭氧利用率接近100%,无需进行臭氧尾气处理;同时为生化处理提供充足溶解氧(DO),实现生化处理对COD和氨氮的进一步有效去除,生化处理无需曝气.在系统出水回流比为30%、臭氧投加量和进水COD量之比为0.44 mg·mg~(-1)的运行条件下,耦合系统处理性能较好.微气泡臭氧催化氧化处理对COD去除率为42.5%,臭氧消耗量与COD去除量比值为1.38 mg·mg~(-1),臭氧利用率为98.0%;生化处理对COD去除率为42.3%;耦合系统整体COD去除率为66.7%,最终平均出水COD浓度为91.5 mg·L~(-1),估算整体臭氧消耗量与COD去除量比值为0.68 mg·mg~(-1),具有较优的技术经济性能.

Combination of Microbubble Catalytic Ozonation and Biological Process for Advanced Treatment of Biotreated Coal Chemical Wastewater

A combination of microbubble catalytic ozonation and biological process was used for advanced treatment of biotreated coal chemical wastewater (BCCW). The performance of the combination system and the influence of the ratio of ozone dosage to influent COD were investigated. The results indicated that the refractory nitrogen-containing aromatics in the BCCW was degraded efficiently by microbubble catalytic ozonation, which resulted in some COD removal, ammonia nitrogen release, and significant improvement of biodegradability. The ozone utilization efficiency was close to 100% and the off-gas ozone did not need to be treated. Sufficient dissolved oxygen (DO) was provided by the microbubble catalytic ozonation for biological treatment without aeration. COD and ammonia nitrogen were removed further in the biological treatment efficiently. Better performance of the combination system was achieved when the system effluent reflux ratio was 30% and the ratio of ozone dosage to influent COD was 0.44 mg·mg^-1. In this case, for microbubble catalytic ozonation, the COD removal efficiency was 42.5%, the ratio of ozone consumed to COD removed was 1.38 mg·mg^-1, and the ozone utilization efficiency was 98.0%. For biological treatment, the COD removal efficiency was 42.3%. For the combination system, the total COD removal efficiency was 66.7%, the average final effluent COD concentration was 91.5 mg·L^-1, and the estimated total ratio of ozone consumed to COD removed was 0.68 mg·mg^-1, indicating better technical and economic performance.