摘要
当前我国正处于大力发展生物天然气产业的阶段,生物天然气的生产需要通过厌氧发酵将生物质转化为沼气,然后进行净化提纯。我国海岸带资源丰富,海藻产量巨大,是潜在的生物质能源和生物天然气原料。采用厌氧发酵技术,将以海带为例的大型海藻转化为甲烷气体,实现我国海藻生物质的有效利用并产生能源气体甲烷。探究在纳米磁铁矿存在下,对该过程的促进作用及影响机制。研究结果表明,添加纳米磁铁矿能够促进海带中有机物质的降解和甲烷产生,总化学需氧量(TCOD)和溶解性化学需氧量(SCOD)去除率分别提高20%和12%以上,甲烷产量可提高1倍以上。同时,纳米磁铁矿有助于使厌氧系统更加稳定,海带发酵产酸后pH恢复中性的速度更快。微生物群落结构分析显示,纳米磁铁矿对系统内电活性微生物丰度提高明显,可以构建微生物直接种间电子传递(DIET)产甲烷的途径。此.外,纳米磁铁矿还能提高5,10-亚甲基四氢甲烷蝶呤还原酶控制基因(mer)和杂二硫化物还原酶控制基因(hdrABC)这2类产甲烷菌胞内重要基因的丰度,促进基于DIET产甲烷代谢通路,为我国发展生物天然气产业提供可能方案,助力“双碳”目标的实现。
The bio-natural gas industry is currently experiencing rapid development in China.Bio-natural gas is purified from biogas,which is produced by anaerobic fermentation of biomass.China′s coastal regions possess abundant seaweed resources,a type of biomass with great potential for biogas production.Therefore,this research investigated biogas production from seaweed through anaerobic fermentation,with the aim of effectively utilizing seaweed and recycling biogas as a renewable energy source.Nano-magnetite was added to the anaerobic reactors to explore the potential to enhance biogas production.The results showed that nano-magnetite could accelerate the degradation of biomass and the production of methane.The removal efficiencies of total chemical oxygen demand(TCOD)and soluble chemical oxygen demand(SCOD)in nano-magnetite reactors increased by about 20%and 12%,respectively,compared with the control reactor,which showed removal efficiencies of 51.4%and 42.5%,respectively.Methane production in nano-magnetite reactors more than doubled,with the highest methane production of 1320 mL at a nano-magnetite concentration of 2.0 g/L.Nano-magnetite enhanced the stability of the anaerobic system and promoted a quicker recovery to neutral pH following acidogenic fermentation of kelp.The pH level in nano-magnetite reactors was always higher than 6.2 and increased gradually to 7.5,while that in the control reactor decreased below 6.0 and then recovered slowly.Analysis of the microbial community structure indicated that nano-magnetite significantly accelerated the enrichment of electroactive microorganisms and facilitated direct interspecies electron transfer(DIET)in methane production.Scanning electron microscopy(SEM)showed that microorganisms and nano-magnetite adhered to each other in nano-magnetite reactors,which was beneficial for DIET to occur among electroactive microorganisms and between electroactive microorganisms and nano-magnetite during the anaerobic methane production process.High-throughput sequencing analysis showed that the electroactive microorganisms were distinctly enriched in nano-magnetite reactors.The abundance of norank_Anaerolineaceae(31.3%,43.4%,47.0%,and 42.1%for 0.2-5.0 g/L nano-magnetite);norank_Bacteroidetes_vadinHA17(2.0%,9.3%,7.6%,and 7.8%);Leptolinea(2.6%,7.3%,6.7%,and 9.1%);Longilinea(2.9%,4.6%,4.8%,and 4.7%);Dechloromonas(2.3%,2.0%,1.2%,and 0.9%);and unclassified_Anaerolineaceae(9.2%,8.9%,8.5%,and 7.1%)all increased compared with the control reactor(17.3%,1.4%,1.6%,3.2%,0.6%,and 2.0%).Additionally,nano-magnetite increased the abundance of the Methylene-H4MPT reductase regulator gene(mer)and.the heterodisulfide reductase regulator gene(hdrABC)in methanogens,enhancing the metabolic pathway of DIET methanogenesis.The abundance of mer was 4.57E-04,5.45E-04,5.75E-04,and 5.50E-04,and hdrABC was 3.69E-05,1.06E-04,1.04E-04,and 1.42E-04,while these values in the control reactor were 2.22E-04 and 6.48E-05,respectively.These findings suggest that nano-magnetite significantly enhances biogas production from seaweed biomass.This technology holds promise for further development to support the advancement of the biogas industry and contribute to achieving the"dual carbon"goal in China.
作者
郭励奥
赵若淇
李司琦
李杨
GUO Li′ao;ZHAO Ruoqi;LI Siqi;LI Yang(School of Chemical Engineering,Ocean and Life Sciences,Dalian University of Technology,Panjin 124000,China)
出处
《能源环境保护》
2025年第5期191-200,共10页
Energy Environmental Protection
基金
国家重点研发计划资助项目(2023YFD1701405-01)。
关键词
生物天然气
海藻
直接种间电子传递
纳米磁铁矿
生物质能源
Bio-natural gas
Seaweed
Direct interspecies electron transfer
Nano-magnetite
Biomass energy
