磁场对活性污泥法处理废水的强化作用

The Increasing Effect of Magnetic Field on Wastewater Treatment by Activated Sludge Process

在一个带污泥回流的完全混合式活性污泥反应器内 ,以炼油厂污水处理场浮选池出水为对象 ,进行了磁场对活性污泥活性影响试验。活性污泥质量浓度为 2 2 0 0mg/L ,废水停留时间为 4h ,进水质量浓度为 2 82mg/LCODCr,反应温度为 2 5～ 30℃ ,pH =7.2。在不加磁场时 ,出水质量浓度为 88mg/LCODCr。在反应器外部加上磁场 ,磁感应强度为 6 4～ 5 80Gs,出水质量浓度为 86～ 78mg/L ,处理效率提高 2 %～ 11%。为了验证磁场对活性污泥活性的影响 ,进行了不加磁场和磁感应强度为 5 0 0Gs的动力学参数测定试验 ,细胞平均停留时间为 0 .8～ 3.1d ,废水停留时间为 4h。试验结果表明 ,半速度系数Ks 由无磁场的 113mg/LCODCr下降到 10 9mg/LCODCr,产率系数Y由 0 .45上升到 0 .49,微生物自身氧化率由 0 .0 9d-1上升到 0 .11d-1。

The wastewater from flotation tank was treated by a bench-scale continuous-flow stirred-tank,ρ(MLSS)=2 200 mg/L,the retaintion time of the wastewater,θ=4 h,the concentration of influent,S_0=282 mg/L COD_ Cr ,the concentration of effluent,S=88 mg/L COD_ Cr .The magnetic field was put outside the part of the aeration tank. When the magnetic density was changed from 64 Gs to 580 Gs ,S was changed from 86 mg/L COD_ Cr to 78 mg/L COD_ Cr with the removal efficiency of COD_ Cr increased by 2%～11% compared with non-magnetic field. A bench-scale continuous-flow stirred-tank reactor with solid recycle was used for the determination of kinetic coefficients.The mean cell residence time θ_c =0.8～3.1 d, the wastewater residence time is θ=4 h. The result of the experiment shows that when the magnetic density is 500 Gs the half-velocity constant K_s=109 mg/L COD_ Cr , yield Y=0.49,whereas K_s =113 mg/L,Y=0.45 with no effect of the magnetic field.