倒置A~2/O-MBR(平板膜)处理城市污水的中试研究

针对城市生活污水,研究了两点进水倒置A2/O-MBR(平板膜)系统(以下简称系统)对COD、NH+4-N、TN、TP、出水SS影响。结果表明,该系统对COD、NH+4-N具有较高的去除率,出水符合GB18918-2002中一级A标准;当混合液回流比为200%时,系统出水TN浓度小于15 mg/L;正常排泥后,系统对TP的去除率达83%左右;平板膜破损会导致出水SS、COD会受到影响。膜对COD、TP、SS有直接截留作用,由于系统出水几乎没有固体损失,可以精确控制污泥龄,有利于世代周期较长的硝化菌和反硝化菌生长;系统中的污泥浓度可以提高至15 000 mg/L,此时,即使进水量提高0.5倍,出水水质仍保持良好。

Combined reversed A2/O-MBR(flat-sheet membrane) process treating municipal wastewater

The performance of the dual-intake reversed A²/O-MBR System(hereinafter referred to as the "system") processing municipal wastewater was evaluated by inspecting indicators such as COD, NH₄⁺-N, TN, TP and SS. Results show that the system had high COD and NH₄⁺-N removal rates, the effluent COD and NH₄⁺-N confirmed to one-class a permitted criteria of the GB18918-2002. The effluent TN concentration was under 15 mg/L when the mixed liquor reflux ratio reached 200%. The system TP removal rate reached about 83% under normal excess sludge discharge operation. The effluent SS and COD could be affected by damaged flat-sheet membrane. COD, TP and SS can be intercepted directly by the membrane system and due to the nearly 100% solid retention, the system SRT can be controlled properly to in favor of the growth of long life-cycle microorganisms such as nitrifying bacteria and denitrifying bacteria. Thanks to the good solid retention effect, the system effluent can still be good with sludge concentration up to 15 000 mg/L even influent increased by 50%.