优化污泥回流方式对多级AO-MBR工艺的影响

Influence of Optimized Sludge Reflux Mode on Multilevel AO-MBR Process

采用处理水量为0.15 m^(3)/h的中试装置,开展多级AO-MBR工艺处理低C/N城市污水试验研究,通过优化污泥回流方式、溶解氧及污泥浓度控制等措施,降低高溶解氧污泥回流对前端生化池的影响,实现出水水质达到地表水准Ⅳ类标准(TN除外)。结果表明,在耦合MBR工艺的形式下,经过生化池多级回流能显著保证各反应区的溶解氧环境,保持各反应区的污泥浓度平衡,进一步提高出水水质。在水温低于12℃、进水TN质量浓度为23~33 mg/L时,采用回流方式4能稳定保证TN去除率达到60%以上,实现出水TN质量浓度达到10 mg/L左右;进水TP质量浓度为2~4 mg/L时,TP去除率达到85%以上,实现出水TP质量浓度低于0.3 mg/L的要求。

A test device with treatment scale of 0.15 m^(3)/h was used to carry out an AO-MBR process to treat low C/N urban wastewater.Best sludge return form was explored to reduce the impact of high dissolved oxygen sludge return on the front biochemical tank,by optimizing the sludge return mode,dissolved oxygen and sludge concentration control and other measures.Eventually,the effluent quality to reach the surface levelⅣstandard was achieved.The results showed that in the form of coupled MBR process,biochemical tank could significantly ensure the dissolved oxygen environment of each reaction zone and maintain the balance of sludge concentration in each reaction zone by multi-stage reflux,so as to further improved the effluent quality.When the water temperature was below 12℃and the influent TN was 23~33 mg/L,the reflux mode 4 could stably ensure that the TN removal rate reached more than 60%and the effluent TN reached about 10 mg/L.When the influent TP was 2~4 mg/L,the TP removal rate was more than 85%,and the effluent TP was less than 0.3 mg/L.