混凝技术处理厌氧消化污泥脱水液试验研究

Experimental study on coagulation treatment of anaerobic digestion sludge dewatering solution

为满足厌氧氨氧化工艺对悬浮物(SS)和铁浓度的进水要求,采用混凝技术对厌氧消化污泥脱水液进行预处理。通过曝气试验和正交试验,确定了厌氧消化污泥脱水液的最佳曝气量、曝气时间和混凝工艺条件;基于单因素试验,得到最佳工艺条件为:快搅(250 r/min)90 s、慢搅(90 r/min)120 s、助凝剂投加时间30 s、静置15 min、聚合氯化铝(PAC)投加量20 mg/L、聚丙烯酰胺(PAM)投加量1 mg/L、pH值为7.0,此时厌氧消化污泥脱水液中的浊度和总铁去除率分别为97.63%和98.21%。由此可见,混凝技术处理后的出水不仅可以提高污染物的去除效果,还可以满足后续厌氧氨氧化工艺的进水要求。

In order to meet the requirements of the suspended solids(SS)and iron concentration in the influent of anaerobic ammonia oxidation process,the coagulation technology was used to pretreat the sludge dewatering solution from anaerobic digestion.Through aeration test and orthogonal test,the optimal aeration intensity,aeration time and coagulation process conditions of anaerobic digestion sludge dewatering liquid were determined.Based on single factor test,the best process conditions were obtained as follows:(250 r/min)90 s of fast stirring,(90 r/min)120 s of slow stirring,30 s of coagulant aids dosing time,15 min of standing time,20 mg/L of polyaluminium chloride(PAC),1 mg/L of polyacrylamide(PAM),7.0 of pH value.At this time,turbidity and total iron removal rates in anaerobic digested sludge dewatering solution were 97.63%and 98.21%,respectively.The effluent treated by coagulation can not only improve the removal effect of pollutants,but also meet the influent requirements of subsequent anaerobic ammonium oxidation process.