絮凝沉淀预处理养猪废水影响因素研究

Study on the Factors Affecting Pretreatment Efficiency of Piggery Wastewater by Flocculation Sedimentation

以江西省鹰潭市某养猪场沼液废水为研究对象,分别通过添加质量浓度为150 g·L-1的聚合氯化铝(PAC)、50 g·L-1的聚合硫酸铝(PFS)以及5 g·L-1的聚丙烯酰胺(PAM),探讨了沉淀时间和pH对絮凝沉淀影响。结果表明:①PAC为絮凝剂时,污染物去除率随静置时间增加而逐渐增大,当添加PFS和PAM为絮凝剂时,综合考虑时间成本以及去除率,建议控制沉淀时间为25min和20min。②当添加PAC为絮凝剂时,酸性条件下有利于氨氮和COD的去除,碱性条件下有利于TP的去除,SS在中性条件下去除效果最好。③添加PFS为絮凝剂时,酸性条件下有利于COD和氨氮的去除,中性条件下有利于TP的去除,碱性条件下有利于SS的去除。④添加PAM为絮凝剂时,酸性条件下有利于SS的去除,碱性条件下有利于氨氮和TP的去除,COD在中性环境中去除效果最好。

Taking the biogas wastewater of a pig farm in Yingtan city,Jiangxi province as the research object,by respectively adding 150 g·L-1 polyaluminum chloride(PAC)and 50 g·L-1 polyaluminum sulfate(PFS)and 5 g·L-1 polyacrylamide(PAM),the effect of sedimentation time and pH on flocculation sedimentation was investigated.The results showed that:(1)When PAC was used as flocculant,the removal rate of pollutants increased with gradual increase of the sedimentation time;when adding PFS and PAM as flocculants;considering the time cost and removal rate,it was recommended to control the sedimentation time in 25 min and 20 min.(2)When PAC was added as flocculant,acidic condition was beneficial to ammonia nitrogen and COD removal,alkaline condition was beneficial to the removal of TP,and the removal effect of SS was the best under neutral conditions.(3)When PFS as flocculating agent was added,COD and ammonia nitrogen were easy removed under acidic condition,TP was easy removed under neutral condition,and SS was easy removed under alkaline condition.(4)When PAM was added as flocculant,acidic condition was beneficial to SS removal,alkaline condition was beneficial to ammonia nitrogen and TP removal,and COD had the best removal effect in neutral environment.