MBR工艺强化脱氮除磷处理滇池农业面源污水的调控方法及实际应用

为保证滇池环湖截污体系已建混合水质净化厂MBR工艺实现出水氮磷稳定达标，通过现场搭建中试规模的系统，研究了外加碳源(乙酸钠)和除磷剂(聚合氯化铝)投加量对实际污水中氮磷强化去除的关系，提出了针对滇池农业面源污水常年进水水质质量浓度、碳氮比以及碳磷比均较低，TN和TP质量浓度波动大的特点，可灵活采用外加碳源(乙酸钠)和辅助化学除磷(PAC)的双调控方法或辅助化学除磷的单调控方法，在能够使出水中氮磷达标稳定的前提下，节约运行成本。同时，以中试研究参数为基准，有效地提高了洛龙河混合水质净化厂的实际运行调控效率，缩短了整个系统优化调整时间，并最终实现净化厂各项出水水质参数稳定达标，特别是TP质量浓度稳定低于0.3 mg/L的地方标准要求，预计滇池现有的两座MBR工艺处理厂每年TP的减排量可达65.3 t。

Regulating method and practical application of MBR process intensified denitrification and dephosphorization treatment of agricultural non-point source sewage in Dianchi Lake

In the intersecting system around Dianchi Lake, a mixed water purification plant was built with MBR process. To ensure that the nitrogen and phosphorus concentration of the MBR effluent met the discharge standard stably, a pilot-scale system was built on site to explore the effects of supplymentary carbon source (sodium acetate) and phosphorus removal agent (polyaluminum chloride) dosage on the enhanced removal of nitrogen and phosphorus in actual sewage, respectively. Due to perennial low concentration of influent water quality, low carbon-nitrogen ratio and carbon-phosphorus ratio of the agricultural non-point source sewage of Dianchi Lake, as well as large fluctuation of the TN and TP concentrations, the flexible use of the dual control method of external carbon source (sodium acetate) and auxiliary chemical phosphorus removal (polyaluminum chloride) or the single control method of auxiliary chemical phosphorus removal was proposed, which could save operating costs with the precondition that the nitrogen and phosphorus in the effluent could be up-to-standard discharged stably. At the same time, based on the pilot study parameters, the actual operation and regulation efficiency of the Luolong River Purification Plant was effectively improved, the optimization and adjustment time of the entire system was shortened, and the stability of effluent water quality reaching the discharge requirement in the purification plant was finally achieved. Especially the TP concentration was stably lower than the local standard requirement of 0.3 mg/L. It was estimated that the two purification plants with MBR process around Dianchi Lake could reduce TP emission up to 65.3 t per year.