3种固定式填料在中试IFAS系统中的性能比较及菌群结构解析

Performance comparison and microbial community structure analysis of three fixed fillers in pilot IFAS system

为考察固定式填料在生物膜-活性污泥工艺(IFAS)中的性能和菌群结构,选取弹性立体填料、组合填料以及自制填料3种固定式填料投入中试级别的IFAS反应器好氧池中进行对比,另于小试系统中进行3种填料的脱膜实验。结果表明:组合填料的亲水性最高(接触角为38°),生物膜厚且致密,加上结点的存在,易结团,脱膜率最高为63%;弹性填料21 d基本可以完成生物膜的更新;而自制填料脱膜速率先快后慢,第24天时脱膜率高达80%。在系统运行期间,3种填料对COD、氨氮去除率均在90%以上,出水均达到一级A排放标准。自制填料和组合填料系统的总氮去除率高于弹性填料。当自制填料系统运行27 d以后,TN出水可稳定达到一级A排放标准。与组合填料和弹性填料相比,由于自制填料结构的特殊性,其负载的生物量最多,生物多样性最高,同时,对硝化细菌、反硝化菌和反硝化除磷菌均表现出富集优势。

In order to investigate the performance and microbial community structure of fixed fillers inintegrated fixed film-activated sludge(IFAS)process,three kinds of fixed fillers(elastic filler,combined fillerand self-made filler)were used in the pilot-scale aerobic tank of IFAS reactor for comparison.In addition,biofilm detachment experiments of three fillers were carried out in a small test device.The results showed thatthe combined filler had the highest hydrophilicity(contact angle was 38°),which resulted in the formation ofthick and dense biofilm,and even easy agglomeration due to the existence of nodes,the highest biofilmdetachment rate was 63%.The biofilm on the elastic filler could basically renew within 21 days.The biofilmdetachment rate of the self-made filler changed from fast to slow,and on the 24 th day the biofilm detachmentrate reached 80%.During the operation of the system,the removal rates of COD and ammonia for these threefillers were above 90%,and the effluents meet the first-class A discharge standard.The TN removal rates of thetwo systems filled with self-made fillers and combined filler were higher than that of elastic filler.After 27 daysof the self-made filled system running,TN in the effluent could meet the first-class A discharge standard.Compared with the combined filler and elastic filler,the self-made filler had the most biomass and the highestbiodiversity due to its special structure.Meanwhile,it had enrichment advantages in nitrifying bacteria,denitrifying bacteria and denitrifying phosphorus removal bacteria.This research contributes to the engineeringapplication of IFAS process.