磁化处理对活性污泥胶体颗粒表面的zeta电位的影响

Magnetic treatment for lowering zeta potential of biological sludge

污水处理过程中，二沉池的泥水分离影响整套工艺的效果，用投加混凝剂来降低活性污泥胶体颗粒表面的zeta电位（以下简写活性污泥zeta电位），增加了运行成本。通过磁场磁化可以降低活性污泥zeta电位，达到节省药剂的目的。研究了磁感应强度、磁化时间、磁场位型以及搅拌速率对氧化沟活性污泥zeta电位的影响规律。研究表明，磁化处理能降低活性污泥zeta电位，在磁场中心磁感应强度为0．40T左右及反应器与磁场平行静置磁化时，zeta电位降低幅度最大，平均在46．5％～51．4％。

Coagulant is often added to the secondary clarifier to improve settling of biological sludge by lowering its zeta potential. Magnetic treatment of oxidation ditch sludge was studied as a viable alternative for reducing its zeta potential. The effects of magnetic field induction, magnetization time, magnetic field direction, and stirring rate on zeta potential reduction were determined. Magnetic treatment indeed reduced surface zeta potential of a colloidal sludge sample; however, the potential reduction and its affecting factors were not simply correlated. The maximum sludge zeta potential reduction （46.5% to 51.4%） was achieved when the center field magnetic induction was about 0.4 T and that the beaker/sample was parallel to magnetic field without stirring.