磁絮凝强化技术处理厌氧消化污泥脱水液

为满足后续生物处理单元对固体悬浮物（SS）和铁浓度的进水要求，采用磁絮凝强化技术对厌氧消化污泥脱水液进行预处理。通过正交试验和单因素试验，本文考察了混凝水力条件、聚合氯化铝（PAC）投加量、聚丙烯酰胺（PAM）投加量、磁粉投加量及药剂投加顺序对磁絮凝效果的影响。试验结果表明：磁絮凝强化技术在快搅300r/min（2min）、慢搅100r/min（15min）、静置10min时，依次投加磁粉（40mg/L）、PAC（30mg/L）、PAM（4mg/L）时处理效果最好。在此运行条件下，SS和Fe³⁺去除率分别为97.61%、98.24%、絮凝指数（FI值）取得最大值、zeta电位绝对值最小，絮凝效果最佳。与对照相比，磁絮凝强化技术对SS和Fe³⁺去除率分别可提高3.70%和10.82%，同时絮体最大沉降速度可提高33%。磁絮凝技术处理后的出水不仅可以满足后续生物处理单元对SS和铁浓度的要求，还可以有效提高磁絮凝体的沉降速度，减小沉淀时间，具有较好的实用价值。

Enhanced treatment of anaerobic digestion reject water by magnetic flocculation technology

In order to meet the input water requirements of the concentrations of suspended solid (SS) and iron by subsequent biological treatment units, enhanced magnetic flocculation technology was used to pretreat the anaerobic digestion reject water. The effects of coagulation conditions, i.e., poly aluminum chloride (PAC) dosage, poly acrylamide (PAM) dosage, magnetic powder dosage and the sequence of dosage on magnetic flocculation were investigated by orthogonal experiment and single factor experiment. The results showed that the enhanced magnetic flocculation technology had the best effect when magnetic powder (40mg/L), PAC (30mg/L) and PAM (4mg/L) were added in turn under the conditions of fast stirring of 300r/min (2min), low stirring of 100r/min (15min) and waiting for 10min. The removal efficiencies of SS and Fe³⁺ were 97.61% and 98.24%, respectively. The best flocculation effect was observed with the maximum value of flocculation index (FI value) and the minimum absolute value of zeta potential. Compared with the control group, the removal efficiencies of SS and Fe³⁺ by magnetic flocculation were increased by 3.70% and 10.82%, respectively, and the maximum settling velocity of flocs was increased by 33%. The treated reject water by enhanced magnetic flocculation technology can meet the requirements of SS and iron concentration for subsequent biological treatment units. Moreover, it can effectively improve the sedimentation speed of magnetic flocs and reduce the precipitation time, which has a good practical value.