平板膜生物反应器处理含50%海水污水的优化研究

Treatment Optimization of Wastewater with 50% Seawater by Flat-sheet Membrane Bioreactor

为确定含海水污水的最优处理条件，在生活污水中加入等量海水作为研究对象，研究平板膜生物反应器（MBR）在不同操作条件下（回流比，曝气强度。污泥浓度）的处理效果。结果表明，利用A／O-MBR处理含50％海水污水的最优条件为：回流比为300%；曝气量为3m^3／h；污泥浓度为5000～6000mg／L。出水COD含量为17．9～24．4mg／L，氨氮含量为2．23～3．28mg／L．慈氮含量为7.27～9．05mg／L，均满足一级A的国家标准。COD、氨氮及总氮的去除率分别为94，52％，93．59％和86．69％。造成膜污染的主要因素是膜孔堵塞带来的内部污染，通过水洗-酸洗-碱洗三个步骤可基本恢复膜通量。

To determine the optimum treatment conditions of wastewater containing 50% of seawater, this research studies the treatment effect of flat-sheet membrane bioreactor （MBR） under different conditions of internal reflux ratio （IR）, aeration intensity and sludge concentration. Results show that the optimum treatment conditions of wastewater containing 50% of seawater by A/O-MBR are when IR is set as 300% and aeration rate is 3 m^3/h and MLSS （mixed liquid suspended solids） is 5 000- 6 000 mg/L. The contents of COD,ammonia nitrogen and TN （total nitrogen） in the treated wastewater are respectively 17.9-24.4,2.23-3.28 and 7.27-9.05 mg/L,meeting the first level A of national discharge standard. The removal rates of COD, ammonia nitrogen and TN are 94.52%, 93.59% and 86.69% respectively. Membrane fouling is mainly caused by internal fouling due to membrane-hole blockage, but the membrane flux can be substantially restored by the procedure of washing, scouring and caustic washing.