摘要
养猪废水与稻秆的混合厌氧消化具有资源化利用和环境保护的双重价值,但传统厌氧消化存在有机物降解率低、系统稳定性差和甲烷产量低等问题。为提高产甲烷效率,本研究探究了纳米磁铁矿(50 mg·g^(−1),以TS计)和微生物电解池(microbial electrolytic cell,MEC,外加电压0.6 V)单独或耦合对厌氧消化的影响。结果表明,采用MEC或添加纳米磁铁矿均能显著提高甲烷产量和产气速度,经过45 d的消化,单独添加纳米磁铁矿(M-AD)和单独应用MEC(MEC-AD)的累积甲烷产量分别比对照组(AD)增加了29.2%和13.7%;纳米磁铁矿与MEC耦合(M-MEC-AD)对提高甲烷产量具有协同作用,其累积甲烷产量最高,较M-AD和MEC-AD分别增加了4.3%和18.6%。Gompertz模型拟合结果表明,纳米磁铁矿与MEC耦合缩短了甲烷生产延滞时间且明显提高了甲烷产量。添加纳米磁铁矿和MEC均能增加发酵液中铁离子质量浓度,提高微生物活性,促进有机物水解,M-MEC-AD的稻秆降解率达到70.5%,高于M-AD和MEC-AD的降解率66.8%和65.4%。纳米磁铁矿和MEC单独或耦合均能增强微生物的种间电子传递,加速丙酸和丁酸向乙酸的转化;也能够降低厌氧消化系统中游离氨(free ammonia,FAN)质量浓度,提高厌氧消化系统的稳定性。相关性分析表明,Fe^(2+)是影响累积甲烷产量的重要因素。以上研究结果可为农业废弃物的资源化处理和MEC-AD的工艺优化提供理论参考。
The anaerobic co-digestion of piggery wastewater and rice straw holds dual value for resource utilization and environmental protection.However,traditional anaerobic digestion(AD)faces challenges such as low organic degradation efficiency,poor system stability,and low methane production.To enhance methane yield,this study investigated the individual and combined effects of nano-magnetite(50 mg·g^(−1),based on total solids)and a microbial electrolytic cell(MEC,applied voltage 0.6 V)on anaerobic digestion.Results showed that both MEC and nano-magnetite significantly improved methane production and gas generation rates.After 45 days of digestion,the cumulative methane yields in the nano-magnetite-amended AD(M-AD)and MEC-assisted AD(MEC-AD)systems increased by 29.2%and 13.7%,respectively,compared to the control(AD).The coupling of nano-magnetite and MEC(M-MEC-AD)exhibited a synergistic effect,achieving the highest cumulative methane yield—4.3%and 18.6%higher than M-AD and MEC-AD,respectively.Gompertz model fitting indicated that the combined approach shortened the methane production lag phase and significantly boosted methane yield.Both nano-magnetite and MEC increased the iron ion concentration in the fermentation broth,enhancing microbial activity and promoting organic hydrolysis.The rice straw degradation rate in M-MEC-AD reached 70.5%,surpassing those of M-AD(66.8%)and MEC-AD(65.4%).Individually or combined,nano-magnetite and MEC facilitated interspecies electron transfer,accelerating the conversion of propionate and butyrate to acetate,while also reducing free ammonia nitrogen(FAN)concentration,thereby improving system stability.Correlation analysis identified Fe^(2+)as a key factor influencing cumulative methane production.These findings provide theoretical insights for optimizing agricultural waste valorization and MEC-AD processes.
作者
陈钱
潘云霞
CHEN Qian;PAN Yunxia(College of Engineering and Technology,Southwest University,Chongqing 400700,China)
出处
《环境工程学报》
北大核心
2025年第8期1807-1816,共10页
Chinese Journal of Environmental Engineering
基金
重庆市社会民生科技创新专项项目(cstc2016shmszx80114)。
关键词
养猪废水
厌氧消化
微生物电解池
纳米磁铁矿
piggery wastewater
anaerobic digestion
microbial electrolytic cell
nano-magnetite
