LCFAs降解动力学特性及对厌氧消化各阶段的影响  

Degradation kinetics of LCFAs and effects on anaerobic digestion

作　　者：席钰 鲁斌 陈豪 张孟娜 李倩[1] XI Yu;LU Bin;CHEN Hao;ZHANG Meng-na;LI Qian(Department of Environment and Municipal Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China)

机构地区：[1]西安建筑科技大学环境与市政工程学院,陕西西安710055

出　　处：《中国环境科学》2023年第8期4080-4088,共9页China Environmental Science

基　　金：国家自然科学基金资助项目(52070148);陕西省重点研发计划项目(2022KWZ-25)。

摘　　要：针对长链脂肪酸(LCFAs)影响厌氧消化体系稳定性的问题,研究了不同浓度下3种典型LCFAs(棕榈酸C16:0、硬脂酸C18:0、油酸C18:1)的甲烷化特性及其对厌氧消化的影响.甲烷化结果表明,油酸实现完全降解明显更加缓慢(26d),但比产甲烷活性(SMA)更高,分别为棕榈酸、硬脂酸的1.2、2.7倍,并且延滞期(t0)和最大产甲烷速率(R_(max))随浓度升高呈线性增加,表明饱和度较碳链长度对LCFAs降解动力学影响更大.微生物群落分析表明,油酸组中Clostridium_sensu_stricto、Petrimonas丰度更高(10.38%和10.03%),在β-氧化前可能饱和化产生了多羟基LCFAs,降解相对缓慢;油酸的加入还促进了Methanosarcina、Methanobacterium及Methanomassiliicoccus的富集,强化了氢营养产甲烷路径.此外,3种LCFAs对厌氧消化各阶段均产生抑制作用,产甲烷阶段的抑制程度最强(分别为16.51%、40.49%、63.77%),且受碳链长度与饱和度共同影响.Long chain fatty acids(LCFAs)affect the stability of anaerobic digestion system.The methanogenic properties of 3typical LCFAs(palmitate C16:0,stearate C18:0,oleate C18:1)at different concentrations and their effects on anaerobic digestion were studied.The methanogenic results showed that the complete degradation of oleate was significantly slower(26d),but the specific methanogenic activity(SMA)was higher,which was 1.2 and 2.7 times that of palmitate and stearate.The lag time(t0)and the maximum methane production rate(R_(max))of the oleate group increased linearly with the rising of the concentration.Thus it can be seen that the influence of saturation degree on the degradation kinetics of LCFAs was greater than the carbon chain length.Microbial community analysis showed that the abundance of Clostridium_sensu_stricto and Petrimonas in the oleate group was higher(10.38% and 10.03%).This may be due to the polyhydroxyl LCFAs produced by saturation before β-oxidation,which degrade more slowly.The addition of oleate also enriched Methanosarcina,Methanosobacterium and Methanomassiliicoccus,strengthening the hydrogenotrophic methanogenesis pathway.In addition,the 3LCFAs had inhibitory effects on each stage of anaerobic digestion.The inhibitory degree was the strongest on methanogenesis(16.51%,40.49%,63.77%,respectively),and was affected by both the carbon chain length and saturation degree.

关 键 词：长链脂肪酸 厌氧降解 厌氧消化 动力学 

分 类 号：X703[环境科学与工程—环境工程]