原位电凝聚膜生物反应器处理模拟印染废水

Treatment of simulated dyeing and printing wastewater by in situ electro-coagulation membrane bioreactor

在膜生物反应器（MBR）膜组件两侧设置以铁为牺牲阳极的电凝聚极板,构建原位电凝聚膜生物反应器（SECMBR）,试验考察极板种类、电压梯度、水力停留时间、通断电周期等因素对SECMBR系统特性和对活性艳蓝X-BR模拟印染废水的处理效果的影响。试验结果表明：在温度为20℃,进水pH为6.5~7.0,铁电极换向周期为20 s,当电压梯度为0.4 V/cm,通断电周期为90 s开/90 s关,极板间距为5 cm,水力停留时间为8h,曝气量为0.2 m3/h时,COD去除率和脱色率分别达到99.8%和67.4%,与传统MBR系统相比,其COD去除率提高1.89%~4.10%,色度去除率提高11.7%~32.9%。SECMBR主要是依靠电场和电极溶出的铁离子共同促进微生物降解有机物。运行10 h后,普通膜生物反应器、电场膜生物反应器和原位电凝聚膜生物反应器膜通量分别下降48.5%,43.6%和2.5%。

A novel in situ electro-coagulation membrane bioreactor （SECMBR） was constructed by installing ferric plates on both sides of the traditional membrane bioreactor （MBR） membrane module. As reactive brilliant blue X-BR simulated dyeing and printing wastewater was taken as the research object, the characteristics and treatment efficiency of MBR under electro-coagulation was studied by remolding processing parameters such as electrode type, electrode voltage, HRT, power supply on/off time ratio. The results show that the removal rates of COD and X-BR are 99.8% and 67.4% respectively under the conditions of reactor temperature 20 ~C, initial pH 6.5-7.0, plate reversing period 20 s, voltage gradient 0.4 V/cm, intermittent direct current 90 s on/90 s off, plate distance 5 cm, HRT 8 h and aeration flux 0.2 m^3/h. Compared with traditional MBR, the removal rates of COD and X-BR improve 1.89%-4.10% and 11.7%-32.9% respectively in SECMBR. The organics removal mainly depends on electric field and iron ion from ferric electrode promoting microbe to degrade in SECMBR. The flux reduction of traditional MBR, electric field MBR and SECMBR during 10 h is 48.5%, 43.6% and 2.5%, respectively.