摘要
针对养猪废水中高浓度氨氮对甲烷发酵过程的抑制问题,研究了不同氨氮负荷对厌氧膜生物反应器(anaerobic membrane bioreactor,AnMBR)处理养猪废水效能的影响及生物炭投加的缓解调控效能。结果表明,在(外源)氨氮负荷为0、3000、4500 mg·L^(−1)时,常规AnMBR的甲烷产率分别为85.2%、73.2%、51.7%,生物炭的投加可使甲烷产率提高至93.2%、83.7%、63.7%。随着氨氮负荷的提高,AnMBR对污染物的去除能力下降:氨氮负荷由0提升至4500 mg·L^(−1)时,常规AnMBR对养猪废水中化学需氧量(chemical oxygen demand,COD)、多糖、蛋白的去除率分别由94.0%、95.7%、86.8%降低至92.4%、90.2%、80.2%,生物炭的投加使其去除率维持在92.7%、91.6%、84.3%。进一步研究发现,高浓度游离氨(free ammonia,FAN)的存在是导致AnMBR发酵效能下降的主要原因。且在氨氮负荷由3000 mg·L^(−1)提高到4500 mg·L^(−1)时,常规AnMBR污泥中的可溶性微生物产物(soluble microbial products,SMP)与微生物胞外聚合物(extracellular polymeric substances,EPS)含量分别提高了84.1%、62.6%,其中,芳香族蛋白类是微生物代谢产物的主要物质;生物炭的投加减少了17.9%~27.1%的SMP含量与2.6%~9.3%的EPS含量。挥发性脂肪酸(volatile fatty acids,VFA)甲烷发酵活性实验结果表明,高浓度氨氮主要抑制了乙酸降解微生物的比产甲烷活性,而生物炭的投加利于维持污泥在高氨氮浓度下的乙酸盐降解产甲烷能力。本研究结果可为缓解高浓度氨氮抑制AnMBR处理养猪废水效能的应用提供参考。
To investigate the ammonia inhibition during anaerobic digestion of swine wastewater,the effects of ammonia loading rates on anaerobic membrane bioreactor(AnMBR)treating swine wastewater,and the regulatory benefits of biochar addition were studied.The results showed that when the ammonia load rate was 0,3000 and 4500 mg·L^(−1),the methane yields of conventional AnMBR were 85.2%,73.2%and 51.7%,respectively,which could increase to 93.2%,83.7%and 63.7%by adding biochar.With the increase of ammonia loading rate,the pollutant removal ability of AnMBR decreased.As the ammonia loading rate increased from 0 to 4500 mg·L^(−1),the removal rates of chemical oxygen demand(COD),polysaccharide and protein in swine wastewater by conventional AnMBR decreased from 94.0%,95.7%and 86.8%to 92.4%,90.2%and 80.2%,respectively,while they maintained at 92.7%、91.6%、84.3%after biochar addition,respectively.Further study showed that the existence of high concentration of free ammonia(FAN)was the main reason for the decline of fermentation efficiency of AnMBR.When the ammonia loading rate increased from 3000 mg·L^(−1) to 4500 mg·L^(−1),the contents of soluble microbial products(SMP)and extracellular polymeric substances(EPS)in conventional AnMBR sludge increased by 84.1%and 62.6%,respectively,of which aromatic proteins were the main substances of microbial metabolites.Addition of biochar reduced SMP content by 17.9%~27.1%and EPS content by 2.6%~9.3%.The experimental results of methane fermentation activity of volatile fatty acids(VFA)showed that high concentration of ammonia nitrogen mainly inhibited the specific methanogenic activity of acetic acid-degrading microorganisms,while biochar addition was conducive to maintain the ability of sludge to degrade acetate and produce methane at high concentration of ammonia nitrogen.The results of this study provide some suggestions for the operation of AnMBR treating swine wastewater with high ammonia nitrogen contents.
作者
张波
王高骏
付鹏
陈奕志
张祥
陈荣
ZHANG Bo;WANG Gaojun;FU Peng;CHEN Yizhi;ZHANG Xiang;CHEN Rong(School of Environmental and Municipal Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;Key Laboratory of Northwest Water Resource,Environment and Ecology(Ministry of Education),Xi'an University of Architecture and Technology,Xi'an 710055,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2024年第5期1283-1291,共9页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(52000148)。
关键词
养猪废水
厌氧膜生物反应器
氨氮抑制
生物炭
微生物代谢产物
swine wastewater
anaerobic membrane bioreactor
ammonia nitrogen inhibition
biochar
microbial products
