填料对HBF工艺处理生活污水的影响及其机制

Effection and Mechanism of Filler on Domestic Sewage Treatment Performance by HBF Process

HBF工艺是废水处理的一种有效方法,且填料是该工艺的核心。然而,典型填料对污水处理性能的影响及其机制并不清楚。为此,采用软性填料(RT)、弹性填料(TT)、组合填料(ZT)、酶浮填料(MT)、聚酯填料(JT)和涤纶填料(DT)6种填料构建HBF反应器处理生活污水。结果表明,测试期内COD平均去除率差异不显著(P>0.05),而氨氮的平均去除率差异显著(P<0.05),且MT反应器的COD及氨氮平均去除率均最高。为揭示其差异形成原因,比较了不同反应器内生物膜干重、微生物活性、微生物群落组成及硝化细菌功能基因(amo A、NSR)的表达。结果发现,生物膜干重差异显著(P<0.05)且微生物活性差异显著(P<0.05),生物膜上的细菌群落结构不同但优势菌群均为变形杆菌门、拟杆菌门及厚壁菌门等,MT中amo A、NSR拷贝数均显著高于其他5种填料(P<0.05)。因此,HBF工艺不同填料污水处理性能的差异主要是由生物膜的生物量及功能微生物组成两方面导致。

HBF process （ hybrid biological ＆ fixed film technology） is an effective biological way for treating domestic sewage and other wastewater. In the ease of bioligieal treatment, mieroorganisnl is undoubtly core unit. However, the effects of filler upon eharateristies of pollutant removal and corresponding meehanisnl are still unclear. Consequently, six types of fillers were used, including soft filler （FIT）, elastomerie filler （TT）, combination filler （ZT）, enzyme floating filler （MT）, polyester filler （JT） and terylene filler （DT） to construct HBF reactors for treating domestic sewage. The results show that the difference of average removal efficiency of COD during the test period is not significant （ ranging from 79. 35% to 91.72%, P〉0. 05） , while the difference of removal efficiency of ammonia nitrogen is significant （ ranging from 67. 12% to 88. 12%, P〈0. 05）. The average removal rates of COD and ammonia nitrogen of MT reactor are the highest, which are 91.72%, 88.12% respectively. To reveal the causes of the difference, microbial activity, bio- film community and the expression of nitrobacterial function genes （amoA, NSR） of biofilms which in different reactors are compared. The results show that the difference of dryweight of biofilm is significant （P〈0. 05） and the difference of microbial activity is extremely significant （P〈0. 01）. The bacterial community structure of different biofilm is different, but the dominant bacterium are Proteobacte- ria, Bacteroidetes and Firmicutes, etc. The copy numbers of amoA and NSR in MT are significantly higher than other five kinds of fillers （P〈0. 05）. Therefore, different performance of HBF process for treating domestic sewage with different fillers is mainly caused by biomass and functional microorganisms of the biofilm.