低曝气下PAC强化SBR工艺同步脱氮除磷

采用序批式反应器(SBR)处理模拟生活污水,研究不同曝气量(30、24、18和12 L/h)下活性污泥同步脱氮除磷规律,并在最佳曝气量下,比较了粉末活性炭-序批式反应器(PAC-SBR)和SBR的脱氮除磷效率,分析了低曝气下PAC-SBR的运行特性和优越性。实验结果表明,当曝气量为24 L/h时,SBR内出水效果较好,其COD、TN和TP的平均去除率分别可以达到90.02%、81.13%和88.12%。在这个最佳曝气量下,PAC-SBR具有明显的优势,其COD、TN和TP的平均去除率均高于SBR,并且PAC-SBR具有较好的污泥沉降性能和较高的活性污泥浓度。在PAC-SBR中,活性污泥以PAC作为微生物载体强化了生物降解效果,并改善了低曝气下污泥絮体的结构,促使反应器内先后形成缺氧-厌氧-微氧/缺氧-缺氧的环境,利于同步硝化反硝化和反硝化聚磷,提高了PAC-SBR的同步脱氮除磷效率。

Powder activated carbon strengthening SBR for simultaneous nitrogen and phosphorus removal under limited aeration

The experiment was carried out in a sequencing batch reactor (SBR) treating simulated domestic sewage. The performance of simultaneous removal of nitrogen and phosphorus was investigated under different aeration rates(30,24,18 and 12 L/h). During the optimal aeration rate, the simultaneous nitrogen and phosphorus removal efficiency between powder activated carbon-sequencing batch reactor (PAC-SBR) and SBR was compared. In addition, the operating characteristics and the superiority of PAC-SBR under limited aeration were analyzed. The results showed that the average removal efficiency of COD,TN and TP in SBR achieved 90.02%,81.13% and 88.12%, respectively at the aeration rate of 24 L/h. Meanwhile, the PAC-SBR showed obvious advantages such as higher average removal efficiency of COD,TN and TP as well as better settle ability and higher sludge concentration. It was noted that the activated sludge using PAC as biological carrier under limited aeration could strengthen biodegradation and improve the flocculate structure, which led to successive anoxic-anaerobic-low aerobic/anoxic-anoxic environment in PAC-SBR. That condition was available to simultaneous nitrification-denitrification and denitrifying phosphorus removal. Therefore, the operation of PAC-SBR enhanced the simultaneous nitrogen and phosphorus removal efficiency.