磁场对活性污泥脱水性能的影响

Study on Effect of Magnetic Treatment on Sludge Dewatering Ability

研究了磁场对城市污水处理厂活性污泥脱水性能的影响,结果表明:磁场能够降低污泥比阻、降低污泥颗粒表面电极电位(zeta电位)、提高污泥离心脱水性能,改善了污泥脱水性能.考察了磁化时间和磁场强度对污泥比阻和污泥颗粒表面电极电位的影响,结果表明:3#磁场磁化30 min污泥的脱水性能得到最有效的改善;在磁场作用下,污泥滤液ρ(CODCr)和ρ(NH4+)都在短时间内升高,随后降低并趋于稳定(ρ(CODCr)的最大变化率为60%;ρ(NH4+)的变化率仅为5%).比较了3#磁场不同位型对污泥的影响,结果表明,平行磁化效果明显优于垂直磁化,其对电极电位的影响较大(降幅达46.5%),但对比阻影响较小.通过不同药剂(FeCl3,PAM)与磁场联用的方法调理污泥发现,FeCl3和磁场联用时,污泥离心脱水速率(1 800 r/min,离心2min)和离心脱水程度(4 800 r/min,离心30 min)较仅使用FeCl3时有显著的提高;但是磁场作用下FeCl3与PAM混用时,其作用效果不佳.

The effect of various parameters on sludge dewatering ability in magnetic treatment for municipal sludge was investigated. The results show that specific resistance filtration （SRF） and zeta potential of sludge can be reduced, dewatering ability of centrifugation of sludge can be improved, and so sludge dewatering ability can be improved in magnetic field. SRF and zeta potential of sludge in various magnetic time or magnetic intensity were researched, the optimal parameter is 3^# （magnetic intensity） and 30min （magnetic time）. In magnetic field it is disciplinary that CODc, and NH4^＋ can be increased in short time and then reduced to invariableness （the most extent of CODc, increase is up to 60%, NH4＋ only to 5% ）. Contrasting to the effect of sludge in two different site type of 3^# magnetic field, it is shown that the parallel magnetic is better than the vertical magnetic, zeta potential of sludge was greatly influenced （the most extent of reducing is up to 46.5% ）, but little for SRF. Some medicament associated with magnetic was used to treat sludge, when FeC13 associated with magnetic was used, velocity of centrifugation（solid content of the cake after 1 800 r/min-2 min-centrifugation） and extent of centrifugation （solid content of the cake after 4 800 r/min-30 min-centrifugation） were better than only FeCl3 used; but when FeCl3 and PAM are associated with magnetic, the effect is bad.