厌氧动态膜生物反应器中动态膜形成及其运行周期的影响因素分析

Analysis on factors influencing formation of dynamic membrane and operational cycle in anaerobic dynamic membrane bioreactor

为探究影响厌氧动态膜生物反应器(AnDMBR)稳定运行的因素,选用不锈钢网为基材构建AnDMBR并用于处理生活污水,着重考察了不锈钢网孔径(200、300和500目)、混合液污泥浓度及膜通量对AnDMBR成膜及运行周期的影响。结果表明:不锈钢网的目数越大,动态膜形成越快,但运行周期较短;低污泥浓度成膜时间较慢,但运行周期较长;污泥胞外多聚物(EPS)对动态膜的形成及运行周期影响较大,EPS越高,动态膜形成越快,但动态膜堵塞越严重;高通量更容易导致动态膜堵塞。选用300目的不锈钢网,在污泥浓度为2 000 mg·L^(-1),通量为32 L·(m^2·h)^(-1)的条件下开展的连续实验表明,AnDMBR稳定运行周期可达240 h。清洗实验结果表明离线清洗方式更适用于动态膜的清除。

An anaerobic dynamic membrane bioreactor（An DMBR） was established by using stainless steel mesh as base material for dynamic membrane formation to explore the factors affecting the stable operation of An DMBR for treatment of domestic wastewater. The influences of stainless steel mesh pore size（200, 300 and 500 mesh）, sludge concentration and membrane flux on the formation of dynamic membrane and operational cycle were investigated.The results showed that the larger sieve mesh number of stainless steel made faster formation of dynamic membrane but shorter operation cycle. The operational cycle was longer with lower sludge concentration, but the dynamic membrane formation was slower. The effect of extra-cellular polymeric substances（EPS） on the formation of dynamic membrane and operational cycle is larger. The higher EPS concentration led to faster dynamic membrane formation and more serious membrane blocking. Higher flux also led to more severe membrane blocking. When stainless steel of 300 mesh was used as the base material, the sludge concentration was 2 000 mg·L^（-1）, and the flux was 32 L·（m^2·h）^（-1）, the operational cycle of An DMBR could be extended to 240 h in continuous experiment. The results of membrane cleaning experiments showed that off-line physical cleaning was more efficient for An DMBR.