耦合回流污泥预浓缩系统的新型氧化沟工艺强化除磷

针对传统的"厌氧+氧化沟"运行模式对低碳源污水除磷能力不佳的问题,采用耦合回流污泥预浓缩系统的新型氧化沟工艺对其强化除磷进行了中试实验研究。通过采用回流污泥预浓缩系统,调试回流污泥浓缩比,提高系统的除磷能力。研究结果表明,在控制最佳回流污泥浓缩比为55%的情况下,出水TP浓度和去除率分别为0.92 mg/L和67.5%,相比于浓缩比为100%、70%、50%和30%的工况,其去除率分别增加了24.3%、27.3%、8.2%和28.6%,强化了系统的除磷效果。另外,ORP可以预示预缺氧池内无效释磷和反硝化程度,以此作为自动调整最佳回流污泥浓缩比的控制参数。

Improving phosphorus removal by pre-concentration of return sludge in novel oxidation ditch system

In order to solve the problem that the traditional "anaerobic zone + oxidation ditch (OD)" process had a low phosphorus removal efficiency on treating low-carbon municipal wastewater, a novel OD integrated return activated sludge (RAS) pre-concentration system was adopted in this pilot-scale study. RAS pre-concentration system was adopted for promoting the phosphorus removal efficiency through varying the RAS pre-concentration ratio in this process. The results showed that under the optimal RAS pre-concentration ratio(55%)operational condition, effluent TP concentration was 0.92 mg/L, and the removal rate of TP was 67.5%, which increased by 24.3%, 27.3%, 8.2% and 28.6% comparing with the different operations in the RAS pre-concentration ratios of 100%, 70%, 50% and 30%, respectively. Obviously, it improved the effect of the phosphorus removal. Otherwise, ORP (oxidation reduction potential) could predict secondary phosphorus release and denitrification react degree in pre-anoxic tank, so it could be the control parameter to regulate the optimal RAS pre-concentration ratio automatically.