不同电子受体驯化聚糖菌反硝化过程及N2O释放特性  

CHARACTERICS OF DENITRIFICATION AND N2O EMISSION OF ACCLIMATED GLYCOGEN ACCUMULATING ORGANISMS USING DIFERENT ELECTRON ACCEPTOR

作　　者：鞠洪海[1] JU Hong-hai(Department of Architecture Engineering,Yantai Vocational College,Yantai 264670,China)

机构地区：[1]烟台职业学院建筑工程系,山东烟台264670

出　　处：《环境工程》2020年第9期113-118,共6页Environmental Engineering

基　　金：国家自然科学基金项目(51668031);烟职博士基金2018002号。

摘　　要：利用序批式(sequencing batch reactor,SBR)生物反应器,采用厌氧-好氧运行方式,以乙酸钠为碳源,在控制进水P/COD<2/100条件下,成功实现了聚糖菌(glycogen accumulating organisms,GAOs)富集。缺氧初始阶段ρ(NO-x-N)为30.0 mg/L,经厌氧-缺氧驯化后,反硝化聚糖菌(denitrifuing GAOs,DGAOs)可利用聚-β-羟基脂肪酸酯(poly-β-hydroxyalkanoate,PHA)为内碳源进行反硝化,且分解利用的PHA中80%以上为聚-β-羟基丁酸酯(poly-β-hydroxybutyrate,PHB)。高浓度NO-2抑制DGAOs活性,厌氧PHA合成降低,且缺氧段PHA分解产生的能量较多地用于储存糖原(glycogen,Gly)。NO-3和NO-2还原过程中,PHA降解速率分别为19.28,10.02 mg/(g·h),内源反硝化速率分别为3.32,2.29 mg/(g·h),TN去除率达95%以上。随NO-2/NO-x增加,N 2O平均产率由29.1%增至59.0%。高浓度NO-2对氧化亚氮还原酶(Nos)活性抑制作用以及Nos和亚硝态氮还原酶(Nir)之间的电子竞争过程,是导致NO-2内源反硝化过程中N 2O大量释放的主要原因。Using an anaerobic-aerobic sequencing batch reactor(AO-SBR),the glycogen accumulating organisms(GAOs)had been enriched with sodium acetate as the carbon source and the P/C ratio lower than 2/100.Cultured in anaerobic-anoxic operation mode,the acclimated GAOs could perform endogenous denitrification reaction with NO-x-N as electron acceptor and poly-β-hydroxyalkanoate(PHA)as electron donor,where PHB(poly-β-hydro-xybutyrate)accounted for more than 80%of the PHA decomposition and utilization.The higher NO-2 concentration inhibited the activity of DGAOs,which led to the decrease of PHA synthesis.More energy from PHA decomposition would be used for glycogen storage.During the reduction process of NO-3 and NO-2,the PHA degradation rate was 19.28 mg/(g·h)and 10.02 mg/(g·h)respectively,which resulted in the related endogenous denitrification rates were 3.32 mg/(g·h)and 2.29 mg/(g·h).The TN removal efficiency reached more than 95%in the end.With the increase of NO-2/NO-x,the N 2O yield during the endogenous denitrification process increased from 29.1%to 59.0%.The higher NO-2 inhibition on the activity of Nos,as well as the electron competition between Nir and Nos,resulted in the higher N 2O production during PHA-driven denitrification by DGAOs.

关 键 词：聚糖菌 电子受体 内源反硝化 氧化亚氮N 2O 电子分配 

分 类 号：X172[环境科学与工程—环境科学] X703