PAC对SBR系统中传质-反应过程的影响研究

Research on the Influence of PAC on The Mass Transfer-reaction Process in SBR System

聚合氯化铝(PAC)作为絮凝剂被广泛应用于各污水处理厂,其残余可对后续生物反应系统产生一定影响。以序批式活性污泥反应器(SBR)反应系统为研究对象,考察了残余PAC对该系统中体积溶氧传递系数(k_(L)a)与胞外聚合物(EPS)中蛋白质含量的影响,并对k_(L)a与EPS的蛋白质含量两者的相关性进行了分析。结果表明:残余PAC不利于SBR系统内活性污泥的溶解氧传质,破坏活性污泥微生物正常的EPS分泌系统使其蛋白质含量降低,进而导致活性污泥微生物中毒失活,阻碍系统内的传质-反应过程。反应系统中k_(L)a与EPS的蛋白质含量表现为显著正相关性,相关系数r=0.9462,说明EPS中蛋白质对溶解氧传质有着重要的影响作用,EPS中蛋白质含量升高可促进溶解氧传质,提高活性污泥活性。

Polyaluminum chloride(PAC)is widely used as a flocculant in sewage treatment plants,and the residue had some influence on the subsequent biological reaction system.In this study,the influence of residual PAC on the volume dissolved oxygen transfer coefficient(k_(L)a)and the protein content in extracellular polymer substances(EPS)in the sequencing batch activated sludge reactor(SBR)reaction system were investigated,and the correlation between k_(L)a and the protein content in EPS was analyzed.The results showed that the residual PAC was not conductive to the dissolved oxygen transfer in the activated sludge in the SBR system,and it destroyed the normal EPS secretion system of the activated sludge microorganism,thus reducing its protein content,leading to the toxic inactivation of the activated sludge microorganism,and hindering the mass transferreaction process in the SBR system.The k_(L)a and the protein content of EPS in the reaction system showed a significant positive correlation,with the correlation coefficient r=0.9462,indicating that the protein in EPS had an important effect on the mass transfer of dissolved oxygen,and the increased protein content in EPS could promote the mass transfer of dissolved oxygen and improve the activity of the activated sludge.