微絮凝-砂滤保障再生水的生物安全性研究

Study on Biological Safety of Micro-Flocculation Sand Filtration to Ensure Regenerated Water

将微絮凝-砂滤工艺用于城市污水处理厂的深度处理,利用中试装置研究滤层厚度对砂滤池去除CODCr、TP、氨氮、SS的影响,并在昆山某城市污水处理厂微絮凝-砂滤工艺的V形滤池中取样,研究滤层厚度对砂滤池去除总大肠菌群的影响。结果表明:当过滤速度为5~9 m/h时,砂滤池对水中TP的截留主要发生在0~90 cm的滤层内,此时出水能够达到GB 18918—2002《城镇污水处理厂污染物排放标准》一级A标准;微絮凝-砂滤工艺能有效保障出水的生物安全性,在絮凝反应和物理截留双重作用下,可将总大肠菌群数降低1~1.7个数量级。

The micro-flocculation sand filtration process is applied to the deep treatment of urban sewage treatment plants.A pilot plant is used to study the effect of filter layer thickness on the removal of CODCr,TP,ammonia nitrogen,and SS in the sand filter.Samples are taken from the V-shaped filter of the micro-flocculation sand filtration process in a sewage treatment plant in Kunshan to study the effect of filter layer thickness on the removal of total coliform bacteria in the sand filter.The results show that when the filtration speed is 5~9 m/h,the retention of TP in the water by the sand filter mainly occurs within the 0~90 cm filter layer.At this time,the effluent can meet the Class A standard of GB 18918-2002 Pol lutant Discharge Standard for Urban Sewage Treatment Plants.The micro flocculation sand filtration process can effectively ensure the biological safety of the effluent.Under the dual effects of flocculation reaction&physical interception,the total number of coliform bacteria can be reduced by 1~1.7 orders of magnitude.