基质暴露水平对ANAMMOX微生物活性及生物量的影响

Influence of Substrate Exposure Level on ANAMMOX Microbial Activity and Biomass

基质暴露水平对ANAMMOX微生物的生长代谢有着重要意义,目前关于基质暴露水平对ANAMMOX污泥长期富集过程中生长特性的研究少有报道.采用两个连续流搅拌反应器,在逐步提升进水负荷的过程中,研究了高基质暴露水平培养方式(R1:出水NH4+-N和NO2--N浓度均为40~60 mg·L^-1)与低基质暴露水平培养方式(R2:出水NH4^+-N和NO2^--N浓度均为0~20 mg·L^-1)对ANAMMOX微生物生长量和生物活性,以及反应器脱氮效能的影响及机制.结果表明,高基质暴露水平培养方式更有利于ANAMMOX反应器脱氮性能的提升.相比之下,高基质暴露水平培养方式下获得的NLR[0.69 kg·(m^3·d)^-1]和NRR[0.41 kg·(m^3·d)^-1]分别是低基质暴露水平培养方式的2倍;高基质暴露水平培养方式下,ANAMMOX污泥浓度(以VSS计)和总基因拷贝数分别达到1805 mg·L^-1和4.81×10^12copies,更有利于ANAMMOX微生物的快速富集培养;低基质暴露水平培养方式下,ANAMMOX污泥的活性更强[以N/VSS计,0.27 g·(g·d)^-1],有利于富集生物活性更高的ANAMMOX污泥.

Substrate exposure levels are vital for the growth and metabolism of ANAMMOX microorganisms,and their effects on growth characteristics of ANAMMOX sludge during the enrichment process have been rarely reported.Using two continuous flow stirred reactors and the process of a gradually developing nitrogen load,the changes in biomass and activity,as well as nitrogen removal efficiency of the reactors were investigated under high substrate exposure level culture mode(R1:effluent NH+4-N and NO2^--N concentrations were 40-60 mg·L^-1)and low substrate exposure level culture mode(R2:effluent NH4^+-N and NO2^--N concentrations were 0-20 mg·L^-1).The results showed that the high substrate exposure level culture mode was more beneficial to the improvement of nitrogen removal performance of the ANAMMOX reactor.For comparison,the NLR(nitrogen load rate),which was 0.69 kg·(m^3·d)^-1,and the NRR(nitrogen remove rate),which was up to 0.41 kg·(m^3·d)^-1,was obtained in the high substrate exposure culture mode.These values were twice as high as those obtained in the low substrate exposure culture mode.Under the culture mode with high substrate exposure level,the sludge concentration(in VSS)and the total gene copy numbers of ANAMMOX reached 1 805 mg·L^-1 and 4.81×10^12 copies,respectively,which was conducive to the rapid enrichment of ANAMMOX microorganisms.In the low substrate exposure level culture mode,ANAMMOX sludge was more active,in N/VSS,0.27 g·(g·d)^-1,which was conducive to the cultivation of ANAMMOX sludge with higher biological activity.