强污泥流失对anammox工艺脱氮性能及菌群的影响

为探究强污泥流失对厌氧氨氧化(anammox)反应器系统脱氮性能、颗粒污泥特性及功能菌群的影响,试验以模拟废水为处理对象构建了上流式厌氧污泥床(UASB)反应器.试验结果表明,损失近一半反应器有效体积的污泥未明显破坏anammox工艺脱氮性能.反应器在4d后总氮(TN)的去除率(RE)达到89.18%污泥EPS含量较高且其PN/PS值(0.12)较低有利于anammox颗粒污泥的形成和集聚.Anammox颗粒污泥粒径>2mm的污泥占到系统总污泥的44.9%,粒径大于0.5mm的污泥占总污泥的84.3%,能够有效持留污泥.厌氧氨氧化菌的优势门为变形菌门(28.03%)、浮霉菌门(15.57%)和绿弯菌门(8.63%),优势属为anammox菌属Candidatus Jettenia(9.63%)和Candidatus Brocadia(3.54%),参与anammox反应的功能基因包括nirS (1.27%)、hzs(1.28%)、hzo(1.29%)、hao(7.04%)和hdh(0.81%),但反硝化菌及其功能基因的存在使得化学计量比Rs (ΔNO₂^--N/ΔNH₄⁺-N)和Rp (ΔNO₃^--N/ΔNH₄⁺-N)低于理论值.

Effects of high sludge loss on the nitrogen removal performance and microbial community of anammox process

In order to study the effects of strong sludge loss on the operation performance, characteristics of granular sludge and nitrogen removal bacteria and functional genes in anaerobic ammonia oxidation (anammox) reactor, a upflow anaerobic sludge blanket (UASB) system was constructed and operated to treat synthetic wastewater. Experimental results showed that the nitrogen removal performance of anammox process was not obviously impaired by high sludge loss, and the total nitrogen (TN) removal efficiency (RE) reached 89.18% after 4days’ recovery. A higher EPS content and a lower PN/PS value of 0.12were beneficial to the formation and agglomeration of anammox granular sludge. The anammox granular sludge with sludge size of > 2mm accounted for 44.9% of the total sludge in this system, and corresponding value was 84.3% for the sludge with size of > 0.5mm, which was advantage to the sludge retention in the reactor. The dominant anammox phyla were Proteobacteria (28.03%), Planctomycetes (15.57%) and Chloroflexi (8.63%), and the domimant genera were anammox bacteria Candidatus Jettenia (9.63%) and Candidatus Brocadia (3.54%). The functional genes involved in anammox reaction included nirS (1.27%), hzs (1.28%), hzo (1.29%), hao (7.04%) and hdh (0.81%), but the presence of denitrification bacteria and related functional genes decreased the stoichiometric ratios Rs (ΔNO₂^--N/ΔNH₄⁺-N) and Rp (ΔNO₃^--N/ΔNH₄⁺-N) of anammox reaction.