University of Illinois at Chicago, Department of Civil, Materials, and Environmental Engineering, 842 West Taylor Street, Chicago, IL 60607, USA.
Genomics and Microbiome Core Facility, Rush University Medical Center, 1653 W. Congress Parkway, Jelke Building, Room 444, Chicago, IL 60612, USA.
Sci Total Environ. 2022 May 15;821:153429. doi: 10.1016/j.scitotenv.2022.153429. Epub 2022 Jan 29.
Biochar-amended soils have been explored to enhance microbial methane (CH) oxidation in landfill cover systems. Recently, research priorities have expanded to include the mitigation of other components of landfill gas such as carbon dioxide (CO) and hydrogen sulfide (HS) along with CH. In this study, column tests were performed to simulate the newly proposed biogeochemical cover systems, which incorporate biochar-amended soil for CH oxidation and basic oxygen furnace (BOF) slag for CO and HS mitigation, to evaluate the effect of cover configuration on microbial CH oxidation and community composition. Biogeochemical covers included a biochar-amended soil (10% w/w), and methanotroph-enriched activated biochar amended soil (5% or 10% w/w) as a biocover layer or CH oxidation layer. The primary outcome measures of interest were CH oxidation rates and the structure and abundance of methane-oxidation bacteria in the covers. All column reactors were active in CH oxidation, but columns containing activated biochar-amended soils had higher CH oxidation rates (133 to 143 μg CH g day) than those containing non-activated biochar-amended soil (50 μg CH g day) and no-biochar soil or control soil (43 μg CH g day). All treatments showed significant increases in the relative abundance of methanotrophs from an average relative abundance of 5.6% before incubation to a maximum of 45% following incubation. In activated biochar, the abundance of Type II methanotrophs, primarily Methylocystis and Methylosinus, was greater than that of Type I methanotrophs (Methylobacter) due to which activated biochar-amended soils also showed higher abundance of Type II methanotrophs. Overall, biogeochemical cover profiles showed promising potential for CH oxidation without any adverse effect on microbial community composition and methane oxidation. Biochar activation led to an alteration of the dominant methanotrophic communities and increased CH oxidation.
生物炭改良土壤已被探索用于增强垃圾填埋覆盖系统中的微生物甲烷 (CH) 氧化。最近，研究重点已经扩大到包括减轻其他成分的垃圾填埋气，如二氧化碳 (CO) 和硫化氢 (HS) 与 CH 一起。在这项研究中，进行了柱试验来模拟新提出的生物地球化学覆盖系统，该系统包括生物炭改良土壤用于 CH 氧化和碱性氧气炉 (BOF) 炉渣用于 CO 和 HS 缓解，以评估覆盖配置对微生物 CH 氧化和群落组成的影响。生物地球化学覆盖层包括生物炭改良土壤 (10%w/w) 和富甲烷氧化菌的活性生物炭改良土壤 (5% 或 10%w/w) 作为生物覆盖层或 CH 氧化层。主要的研究结果是 CH 氧化速率和覆盖层中甲烷氧化菌的结构和丰度。所有柱反应器都能有效地进行 CH 氧化，但含有活性生物炭改良土壤的柱反应器的 CH 氧化速率更高 (133 至 143 μg CH g day)，高于含有非活性生物炭改良土壤 (50 μg CH g day) 和无生物炭土壤或对照土壤 (43 μg CH g day)。所有处理在孵育后甲烷氧化菌的相对丰度都显著增加，从孵育前的平均相对丰度 5.6%增加到最大 45%。在活性生物炭中，由于 II 型甲烷氧化菌（主要是甲基单胞菌和甲基杆菌）的丰度大于 I 型甲烷氧化菌（甲基杆菌），因此活性生物炭改良土壤也表现出更高的 II 型甲烷氧化菌丰度。总体而言，生物地球化学覆盖层在不影响微生物群落组成和甲烷氧化的情况下，显示出 CH 氧化的良好潜力。生物炭的激活导致优势甲烷氧化菌群的改变和 CH 氧化的增加。
