摘要
针对沼气工程(尤其是北方低温地区)产气效能和运行稳定性对温度条件的耐受十分脆弱的问题,采用连续搅拌釜-厌氧膨胀床(CSTR-EGSB)两段式厌氧反应器,以牛粪和水稻秸秆为底物,分别对不同温度条件下的产酸和产甲烷效能进行了评估。结果表明,CSTR产酸反应器中SCOD浓度、pH、总氨氮(TAN)浓度等指标在25~35℃范围内随温度变化的差异较大;当温度由35℃降至25℃时,乙酸占总挥发性脂肪酸(VFAs)的比例由62.9%~70.5%降至46.3%~59.4%。EGSB产甲烷反应器在温度降至15℃时,仍有127.33 mL/(L·d)的沼气容积产率、33.3%的甲烷占比和32.3%的TCOD去除率。高通量测序结果表明,Methanomicrobiaceae(甲烷微菌科)可能在低温产甲烷过程中发挥了重要作用。低温下乙酸生成受限、丙酸积累加剧可能是导致沼气工程产甲烷效率较低的原因之一,可深度开发基于Methanomicrobiaceae和Euryarchaeota_unclassified的抗低温型产甲烷菌剂。
Biogas production efficiency and operational stability of biogas project(especially in the low temperature areas in the north) are very sensitive to the temperature conditions. This paper used a two-stage anaerobic reactor consisting of a continuous stirred tank and an expanded granular sludge bed(CSTR-EGSB) to evaluate the acidogenesis and methanogenesis efficiency at different temperatures with cow manure and rice straw as substrates. The SCOD, pH, total ammonia nitrogen(TAN) in the CSTR(acidogenic reactor) varied greatly when the temperature was in the range of 25-35 ℃. When the temperature decreased from 35 ℃ to 25 ℃, the proportion of acetic acid in total volatile fatty acids(VFAs)decreased from 62.9%-70.5% to 46.3%-59.4%. When the temperature of EGSB(methanogenic reactor)was decreased to 15 ℃, the biogas volumetric yield, proportion of methane and TCOD removal rate were still 127.33 mL/(L·d), 33.3% and 32.3%. The high-throughput sequencing results showed that Methanomicrobiaceae might play an important role in the methanogenesis process at low temperature. The limited acetic acid generation and intensified propionic acid accumulation at low temperature might be one of the reasons for the low methanogenesis efficiency of the biogas project. Therefore, psychrophilic methanogenic agents based on families of Methanomicrobiaceae and Euryarchaeota_unclassified can be further developed.
作者
鹿晓菲
许玉琳
马放
王晨熹
李敏
LU Xiao-fei;XU Yu-lin;MA Fang;WANG Chen-xi;LI Min(School of Municipal and Environmental Engineering,Shenyang Jianzhu University,Shenyang 110168,China;State Key Laboratory of Urban Water Resource and Environment,School of Environment,Harbin Institute of Technology,Harbin 150090,China)
出处
《中国给水排水》
CAS
CSCD
北大核心
2023年第1期65-72,共8页
China Water & Wastewater
基金
辽宁省自然科学基金资助项目(2021-BS-171)
辽宁省教育厅科学研究项目(lnjc201911)
城市水资源与水环境国家重点实验室开放基金资助项目(QG202235)。
