污泥性质对动态膜形成和膜污染的影响

Effect of sludge properties on membrane formation and fouling in a dynamic membrane bioreactor

以一体式尼龙筛网动态膜生物反应器(DMBR)为研究体系,探讨了正常污泥、膨胀污泥和解体污泥的动态膜形成和膜污染特点,并从胞外聚合物(EPS)、相对疏水性(RH)、污泥混合液粘度(μ)、接触角这些物化性质角度定量研究膜污染机理.研究结果表明,膨胀污泥由于丝状菌累积导致严重的泥饼层污染;解体污泥由于胶体颗粒和可溶性物质沉积在膜面堵塞膜孔,使过滤的有效面积减小;而正常污泥膜污染形成缓慢,抗污染性能最好.EPS含量和组成及污泥形态是决定污泥性质并影响动态膜生物反应器膜污染的主要因素.

The dynamic membrane formation and membrane fouling characteristics of normal sludge,bulking sludge and deflocculated sludge were investigated in a submerged nylon mesh dynamic membrane bioreactor（DMBR）,and the fouling mechanisms were explored from the aspects of extracellular polymeric substances（EPS）,relative hydrophobicity（RH）,sludge viscosity（μ） and contact angle.The results showed that the bulking sludge could cause severe cake fouling due to adsorption and bridging of filamentous bacteria.The deflocculated sludge reduced the effective filtration area,which resulted from the deposition of colloidal particles and soluble matter that deposited on the membrane pores.Comparatively,normal sludge had a slightly lower membrane fouling tendency and thus the best performance.It was also found that the EPS content and its composition,and the sludge morphology were the two major factors affecting sludge properties and fouling behaviors of the DMBR.