“化学软化+TUF”组合工艺在焚烧厂垃圾渗滤液的应用研究

Study on the Application of"Chemical Softening+TUF"Combined Process in Landfill Leachate of Incineration Plant

采用“化学软化+TUF”对焚烧厂垃圾渗滤液MBR产水进行预处理,探究了不同Ca(OH)_(2)加药量的软化效果、管式超滤膜的运行稳定性及组合工艺的处理效果、膜污染控制方式和反渗透运行稳定性。结果表明:Ca(OH)_(2)加药量占比为90%时,组合工艺对硬度、SiO_(2)、COD的去除率分别为94.3%、66.7%、30.0%,出水浊度为0.22 NTU,说明组合工艺对硬度、COD、SiO_(2)、浊度均有较好的去除效果。管式膜产水平均通量在390 L/(m^(2)·h)左右,运行压力稳定在0.25 MPa,通量和压力运行稳定,反洗通量恢复性好。采用HCl(5%)+NaOH(3%)+NaClO(5%)的化学清洗方式可能较好地恢复膜通量。组合工艺除硬除浊处理后,后续反渗透运行稳定性明显改善。本研究可以为“化学软化+TUF”在焚烧厂渗滤液废水预处理阶段的应用提供参考。

The"chemical softening+TUF"was used to pretreat the MBR water from the garbage leachate of the incineration plant.The softening effect of different Ca(OH)_(2) dosages,the operation stability of tubular ultrafiltration membrane,the treatment effect of the combined process,the membrane pollution control mode and the operation stability of reverse osmosis were investigated.The results showed that the removal rates of hardness,SiO_(2) and COD by the combined process were 94.3%,66.7%and 30.0%respectively and the turbidity of the effluent of 0.22 NTU under the Ca(OH)_(2) dosage of 90%.The result indicates that the combined process had good removal effects on hardness,COD,SiO_(2) and turbidity.The average flux of tubular membrane production level is about 390 L/(m^(2)·h),the operating pressure is stable at 0.25 MPa,the flux and pressure are stable,and the flux recovery of backwashing is good.The chemical cleaning method of HCl(5%)+NaOH(3%)+NaClO(5%)showed a better restoration of the membrane flux.After the combined process of removing hardness and turbidity,the stability of subsequent reverse osmosis operation was significantly improved.This study can provide a reference for the application of"chemical softening+TUF"in the pretreatment stage of leachate wastewater from an incineration plant.