高效沉淀池与滤池组合工艺在污水处理厂总磷超低排放的应用

Application of High-Efficiency Sedimentation Tank and Filter Combined Process in Ultra-Low Total Phosphorus Emission in WWTP

随着环境要求的提高,污水处理厂排放标准也逐步提高。高效沉淀池与滤池组合工艺广泛作为深度处理设施应用于污水处理厂,以进一步去除生物处理较难去除的TP和SS等污染物。文中通过对某污水处理厂深度处理设施稳定运行一年的运行数据进行分析,研究高效沉淀池与滤池组合工艺对生物处理出水TP去除效果及出水水质情况。结果表明,生物处理出水TP年均值为0.135 mg/L,经过高效沉淀池与滤池组合工艺处理后,出水TP年均值为0.066 mg/L,TP去除率为79.53%。其中,高效沉淀池与滤池的TP去除率分别为50.75%和28.78%。同时,出水TP达到《地表水环境质量标准》中Ⅰ类水和Ⅱ类水标准的天数分别为160 d和204 d,占比43.84%和55.89%,出水TP浓度数值的方差为0.017,水质较为稳定。当污水处理厂出水需要排入环境要求较高的水体,或者作为再生水回用有较高的水质要求时,可通过高效沉淀池“混合+絮凝+沉淀”将大部分溶解性正磷酸盐转化成含磷颗粒并去除大粒径颗粒,再通过滤池过滤去除小粒径颗粒,使污水处理厂实现出水TP超低排放。

With the improvement of environmental requirements,the discharge standards of wastewater treatment plant(WWTP)have been gradually improved.The combination of high-efficiency sedimentation tanks and filters is widely used in WWTP as advanced treatment facilities to further remove pollutants such as TP and SS that are difficult to remove by biological treatment.This paper analyzed the operation data of advanced treatment facility of a WWTP in stable operation for one year,and studied the TP removal effect and effluent quality of the biological treatment effluent by the combined process of high-efficiency sedimentation tank and filter.The results showed that the annual average TP of the biological treatment effluent was 0.135 mg/L,the annual average TP of the effluent after the combined process of high-efficiency sedimentation tank and filter was 0.066 mg/L and TP removal rate was 79.53%.The removal rates of high-efficiency sedimentation tank and filter were 50.75%and 28.78%,respectively.At the same time,the number of days that the effluent TP met the requirements of Environmental Quality Standards for Surface Water for Class I and Class II water standards was 160 days and 204 days,accounting for 43.84%and 55.89%of total.The variance of the TP concentration in the effluent was 0.017.The water quality was relatively stable.When the effluent from the WWTP is discharged into a water body with high environmental requirements or there is a high water quality requirement for the regeneration of the effluent,most of the dissolved orthophosphate can be converted into phosphorus-containing phosphate through a high-efficiency"mixing+flocculation+sedimentation"sedimentation tank.The large-sized particles are removed by the high-efficiency sedimentation tank,and then the small-sized particles are removed by filtering through the filter tank,so that the WWTP can achieve ultra-low TP discharge in the effluent.