活性炭对海水养殖废水处理中动态膜污染的控制过程与作用机制研究

Study on the Control Process and Mechanism of Activated Carbon on Dynamic Membrane Pollution in Mariculture Wastewater Treatment

研究了粉末活性炭(Powdered Activated Carbon,PAC)投加对厌氧/好氧-移动床-动态膜组合生物膜反应器(A/O-MB-DMBR)处理海水养殖废水工艺中的膜污染控制过程与作用机制。结果表明:投加PAC使反应器中生物膜胞外聚合物(Extracellular Polymeric Substances,EPS)的含量下降45.5 mg·g-1,最高增长速率降低62.47%;同时PAC还可使悬浮物粒径增大,有效的控制EPS的积累和膜污染。PAC投加前,反应器在运行16 d时膜通量即降到0.4 L·(m^2·h)-1,而投加后,运行32 d后膜通量仍保持在9 L·(m^2·h)-1,反应器运行周期显著延长。微生物群落分析发现,PAC投加可促进动态膜微生物群落多样性以及物种丰富度,与污泥絮体水解及脱氮相关的拟杆菌门和浮霉菌门相对丰度显著增加,亮发菌属、黄单胞菌属等与EPS产生有关的变形菌丰度显著降低。可见,PAC通过改变反应器生物膜的微生物群落结构、降低EPS含量等过程控制膜污染进程,并最终延长了反应器的运行周期。

This experiment mainly focuses on the membrane fouling control process and mechanism when powdered activated carbon(Powdered Activated Carbon,PAC)is added in anaerobic/aerobic-dynamic membrane combination moving bed biofilm reactor(A/O-MB-DMBR)in mariculture wastewater treatment.The results showed PAC reduced the content of extracellular polymeric substances(Extracellular Polymeric Substances,EPS)in DMBR reactor by 45.5 mg·g-1 and the maximum growth rate by 62.47%.At the same time,PAC increased the particle size of suspended solids,effectively controlling the accumulation of EPS and membrane pollution.Before PAC was added,the membrane flux of DMBR system remained 0.4 L·(m^2·h)-1 at 16 d,and after addition,the membrane flux remained 0.4 L·(m^2·h)-1 at 16 d,the operation cycle was significantly prolonged.The results of microbial community analysis showed that PAC promoted the diversity and species richness of dynamic membrane microbial community,and increased the relative abundances of Bacteroides and Planctomycetes,which can hydrolyze sludge flocs and effectively denitrify,respectively.However,the abundance of Proteobacteria related to EPS production such as Leucothrix and Xanthomarina was significantly reduced.It can be seen that PAC can control the membrane fouling process by changing the microbial community structure of the biofilm and reducing the EPS content,and ultimately prolong the operation cycle of the reactor.