摘要
以城市污水处理厂剩余污泥为研究对象,采用批次试验考察了pH值为5,7,9,10的恒定调节方式和分阶段pH值调节方式对厌氧发酵过程中有机物溶出情况的影响,并利用高通量测序技术分析不同pH值调控方法下的发酵污泥微生物群落结构.结果表明,pH值恒定调节方式下碱性和酸性条件可溶出更多的有机物,积累量在pH=10时达到最大,此时可溶性有机物(SCOD)浓度为323.77mg/gVSS,VFAs产量为183.38mgCOD/gVSS.在发酵初期,以前4d控制pH=10且后续使pH值自然下降的阶段调节方式有利于产酸阶段产出更多的VFAs,其产量最高为208.78mgCOD/gVSS,比pH=10恒定调节下的VFAs总量最大值高出13.90%.采用不同pH值调节方式后微生物丰度在门水平上有显著差异,但主要的优势微生物均为Firmicutes、Proteobacteria、Actinobacteriota和Chloroflexi.对于恒定调节方式,Firmicutes和Actinobacteriota的相对丰度在pH=10的条件下达到最高,为61.14%和15.57%,远高于其他pH值恒定调节下的菌群丰度;对于分阶段pH值调节方式,上述两类微生物较pH=10恒定调节方式的相对丰度又有较大提升,分别提升至68.46%和18.43%.从属水平上来看,与水解酸化有关的菌群(Proteiniclasticum、Bacillus、Acetoanaerobium、Proteocatella和Alkaliphilus等)丰度在pH=10恒定调节中占比为32.38%,在分阶段pH值调节方式中占比为51.62%.分阶段pH值调节方式整体上提高了水解酸化菌的相对丰度,更有利于发酵过程中VFAs的积累.
This experiment focuses on the wasted sludge from municipal sewage treatment plants.Batch texts were taken to explore the effects of different pH regulation methods,which include constant pH adjustment with values of 5,7,9,10 and phased pH adjustment,on the dissolution of organic matter in anaerobic fermentation.The variations of microbial community structure of fermentation sludge under different pH adjustment conditions were analyzed by High-throughput sequencing technology.Results showed that more organic matter could be dissolved under both alkaline and acidic conditions with constant pH adjustment,and the accumulation reached the maximum when pH value was 10.At this point,solluted chemical oxigen demand(SCOD)concentration was 323.77mg/gVSS,and the VFAs was 183.38mgCOD/gVSS.In the case of phased pH adjustment,a constant pH of 10was controlled only in the initial stage of fermentation(the first 4days)and the pH value was naturally reduced in the later stage,this method showed more conducive to the production of VFAs in the acid production stage.This maximum yield was 208.78mgCOD/gVSS,which was 13.90%higher than the maximum total VFAs of same pH value but with constant pH adjustment.At the phylum level,significant differences in microbial abundance appeared after different pH adjustment operations,but the main dominant microorganisms were still Firmicutes,Proteobacteria,Actinobacteriota and Chloroflexi.Under constant pH regulation,the relative abundance of Firmicutes and Actinobacteriota reached 61.14%and 15.57%when pH value was 10,which was the highest beyond other pH values.As for the phased pH regulation,the relative abundance of Firmicutes and Actinobacteriota increased to 68.46%and 18.43%respectively,which grew more proportion than the condition of constant pH adjustment mentioned above.At the genus level,the bacterial abundance related to hydrolytic acidification(Proteiniclasticum,Bacillus,Acetoanaerobium,Proteocatella and Alkaliphilus,etc.)accounted for 32.38%when pH value was constantly 10,and 51.62%under phased regulation.The phased pH regulation improved the relative abundance of hydrolytic acidifying bacteria and was more contributive to the accumulation of VFAs during fermentation.
作者
毕豪华
高春娣
刘奕伟
邢一言
彭永臻
BI Hao-hua;GAO Chun-di;LIU Yi-wei;XING Yi-yan;PENG Yong-zhen(National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology,Faculty of Environment and Life,Beijing University of Technology,Beijing 100124,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第9期4648-4657,共10页
China Environmental Science
基金
国家自然科学基金资助项目(52270017)。
关键词
厌氧发酵
可挥发性脂肪酸
PH值
高通量测序
anaerobic fermentation
volatile fatty acid(VFA)
pH
high-throughput sequencing
作者简介
毕豪华(1998-),男,河南南阳人,硕士研究生,主要研究方向为城镇污水深度处理与资源化利用.发表论文3篇.1720125370@qq.com;高春娣,教授,gaochundi@bjut.edu.cn。
