低温条件下生物转盘处理低浓度污染地表水

为实现低温条件下(冬季水温为8~15℃)快速启动生物转盘处理低浓度污染地表水,采用自然挂膜法G1、活性污泥挂膜法G2和硝化菌挂膜法G3这3种方式进行生物转盘挂膜,并对出水指标与生物膜表观形貌、群落组成进行对比研究。结果表明,从启动速率与抗冲击负荷能力来看,G3>G2>G1;25 d后接种硝化菌的生物转盘对氨氮的去除率即可达到88.78%。稳定运行后,3种挂膜方式的生物转盘对低浓度污染地表水的处理效果相近,对NH4+-N和COD的去除率均可稳定在90%和20%。3种挂膜方式的微生物丰度与种类相似,与硝化反应有关的细菌主要有Nitrosospira、Candidatus nitrotoga、Nitrosomonas,在3种挂膜方式中分别占比15.85%、12.04%、12.47%;与COD降解有关的细菌主要有Reyranella、Thermomonas、Polymorphobacter、Sphingomonas与Arenimonas,在3种挂膜方式中分别占比10.69%、12.39%、15.02%。微生物多样性和均匀度呈现出后端生物转盘盘片大于前端的趋势,说明微生物种类和均匀度与污染物种类和浓度有关。

Treatment of Low Concentration Polluted Surface Water by Rotating Biological Contactor at Low Temperature

In order to quickly start rotating biological contactor(RBC)to treat low concentration polluted surface water at low temperature between 8℃and 15℃in winter,biofilm was successfully attached on the media through three methods,namely natural cultivation(G1),cultivation by inoculating activated sludge(G2)and cultivation by inoculating nitrifier(G3),respectively,and the effluent quality,morphology of the biofilm and microbial community were compared.In term of starting time and anti-shock load capacity,G3 was better than G2,and G2 was superior to G1.After 25 days,the removal rate of ammonium nitrogen could reach 88.78%in G3 system inoculated with nitrifier.During stable operation,similar treatment performance of surface water was obtained in G1,G2 and G3 systems,and the removal rates of NH4+-N and COD could be stabilized at 90%and 20%,respectively.Microbial abundance and species of G1,G2 and G3 systems were similar to each other.Nitrosospira,Candidatus nitrotoga,and Nitrosomonas were the main nitrifiers,and the relative abundance of nitrifiers in G1,G2 and G3 systems were 15.85%,12.04%and 12.47%,respectively.Reyranella,Thermomonas,Polymorphobacter,Sphingomonas and Arenimonas were responsible for degradation of COD,and the relative abundances were 10.69%,12.39%and 15.02%in G1,G2 and G3 systems,respectively.The back-end disks of the rotating biological contactor exhibited higher microbial uniformity and richer diversity than those in the front disks of the rotating biological contactor,indicating that the species and uniformity of the microbial community were related to the type and concentration of pollutants.