污水处理厂达到一级A排放标准中的化学除磷

城镇污水处理厂一级A排放标准中出水总磷应≤0.5mg/L。为达到此排放标准,在生物脱氮除磷工艺后要增加化学除磷。简介了增加化学除磷的必要性及其基本原理,并从工程实际出发,适合的除磷化学药剂为铝盐。具体的药剂选用及投加量可通过试验确定。化学药剂投药点建议在生物反应池好氧段末端附近,距出口的水力停留时间为15～20min。

Chemical Phosphorus Removal for Achieving 1A Standard in Waste Water Treatment Plant

The total phosphorus(TP) of effluent in 1A discharge standard should be equal or smaller than 0.5 mg/L. To arrive at the standard, the author suggested to increase chemical phosphorus removal besides biological nitrogen and phosphorus removal. Then, the necessity and principle of adding chemical phosphorus removal were introduced briefly. According to the project practice, aluminum salt was regarded as the suitable reagent. And the detailed reagent selection and dosage could be determined by the experiment. Otherwise, the chemical reagent putting-inpoint was advised tochoose the ending section of oxic zone of the aeration tank and the hydraulic retention time to the discharge point should be between 15 min and 20min.