Metagenomic analysis reveals that activated carbon aids anaerobic digestion of raw incineration leachate by promoting direct interspecies electron transfer
Metagenomic analysis reveals that activated carbon aids anaerobic digestion of raw incineration leachate by promoting direct interspecies electron transfer
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宏基因组分析表明，活性炭通过促进直接种间电子转移来帮助原始焚烧渗滤液的厌氧消化
DOI：
10.1016/j.watres.2019.06.038
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发表时间：
2019
期刊：
影响因子：
12.8
通讯作者：
Holmes Dawn E
中科院分区：
文献类型：
--
作者：
Lei Yuqing;Sun Dezhi;Dang Yan;Feng Xianlu;Huo Da;Liu Chuanqi;Zheng Kun;Holmes Dawn E
来自城市固体废物（MSW）焚烧厂的原始新鲜渗滤液含有高浓度的挥发性脂肪酸（VFA）、氨和金属，所有化合物严重限制厌氧消化处理效率。这些抑制性化合物使反应器系统不稳定，导致反应器启动时间超过100天，即使沥滤液被大大稀释。在这项研究中，颗粒活性炭（GAC）被纳入生物反应器进料与原料焚烧渗滤液。添加活性炭允许直接处理的原料焚烧渗滤液没有任何启动驯化期，而未经修改的控制反应器立即恶化，并在17天内崩溃。当逐步降低反应器的水力停留时间（HRT）以提高有机负荷（OLR）至25.0kgCOD/（m3·d）时，COD去除率稳定在90%以上。宏基因组学分析表明，在GAC-修正的反应器比种子污泥中更丰富的，已知参与直接种间电子转移（DIET）的物种，地芽孢杆菌和甲烷八叠球菌。此外，编码被认为与膳食有关的蛋白质（如导电皮利和外膜型细胞色素OmcS）的基因丰度显著增加，而参与发酵、硝酸盐（narG）和硫酸盐（dsrA）还原的基因随着实验的进行显著下降。这些结果是显着的，因为这是第一次详细调查的微生物群落的代谢能力，在生物产甲烷反应器，不需要很长的启动期内的原焚烧渗滤液的有效处理。
The raw fresh leachate from municipal solid waste (MSW) incineration plants contains high concentrations of volatile fatty acids (VFAs), ammonia and metals, all compounds that severely limit anaerobic digestion treatment efficiencies. These inhibitory compounds make reactor systems unstable, causing reactor start-up periods to take more than 100 days, even when the leachate is diluted significantly. In this study, granular activated carbon (GAC) was incorporated into a bioreactor fed with raw incineration leachate. Addition of GAC allowed direct treatment of raw incineration leachate without any start-up acclimation period, while the non-amended control reactor soured immediately and collapsed within 17 days. When hydraulic retention time (HRT) of the GAC-amended reactor was stepwise decreased to increase organic loading rates (OLR) to 25.0 kgCOD/(m3·d), COD removal efficiencies remained stable at >90%. Metagenomic analysis of the GAC-amended reactor revealed thatGeobacterandMethanosarcina, species known to participate in direct interspecies electron transfer (DIET), were more abundant in the GAC-amended reactor than the seed sludge. In addition, the abundance of genes coding for proteins thought to be involved in DIET such as electrically conductive pili and the outer membranec-type cytochrome, OmcS, increased significantly, while genes involved in fermentation, and nitrate (narG) and sulfate (dsrA) reduction dropped significantly as the experiment progressed. These results are significant because this is the first detailed investigation into the metabolic capabilities of microbial communities involved in efficient treatment of raw incineration leachate within biomethanogenic reactors that did not require a long start-up period.