摘要
填埋场覆盖层是一种控制甲烷逃逸的最简单可行办法,然而一般的土质覆盖层工程特性差,与微生物甲烷氧化菌的甲烷氧化效能低。生物炭施加到土体中能够改变土体的微环境和微生物活性,进而可影响生物氧化甲烷的效能。为了研究生物炭-甲烷氧化菌改性土的甲烷氧化效率,该研究使用甲烷检测仪,测定不同pH、甲烷浓度、土样干密度和生物炭掺量下,有菌和无菌土样的甲烷降低率的变化规律。结果表明:当无机盐培养液的pH值为7时,甲烷氧化菌具有较高的氧化效能;pH值为9时,甲烷氧化菌的甲烷降低率小于pH值为7时。在一定初始甲烷浓度下,甲烷氧化菌的氧化效能随着初始甲烷浓度的增大而增大,但当初始甲烷浓度超过一定值时会抑制甲烷氧化菌的氧化效能,生物炭掺量和干密度均会影响甲烷氧化菌甲烷削减效能。随着生物炭掺量的增加,生物炭-甲烷氧化菌改性土的甲烷氧化效率是逐渐增大的;在干密度和生物炭掺量为1.20 g/cm3和15%时,无菌和有菌两种工况的甲烷降低率降幅较明显,分别为10.38%和39.72%。由此表明添加生物炭改变了填埋场覆盖层土体的微环境,提高了甲烷氧化菌的甲烷氧化效能,该研究对填埋场温室气体减排、大气污染防治及土体固碳减排具有重要学术意义和实际价值。
The landfill cover is the simplest and most feasible method to control methane emissions.Besides its low gas conductivity,methane emissions can be further reduced due to the methane oxidation by soil microbes.However,ordinary soil covers have poor engineering properties,and the methane oxidation efficiency of soil and microbial methane-oxidizing bacteria is low.Biochar is a carbon-rich,black,refractory solid material obtained through pyrolysis of biomass(such as peanut shells,wheat straw,sawdust,and rice straw)under oxygen-limited conditions.Due to its porous structure,high surface area,and pH characteristics,biochar applied to soil can change the microenvironment of the soil,which in turn can affect the efficiency of methane biological oxidation.To investigate the methane oxidation efficiency of biochar-methane oxidizing bacteria modified soil,methane detectors were used to measure the changes in methane reduction rates of both sterile and non-sterile soil samples under different pH levels,methane concentrations,soil dry densities,and biochar dosages.The results showed that when the pH of the inorganic salt culture solution was 7,the methane-oxidizing bacteria had high oxidation efficiency.The methane oxidation curve at pH value 7 is located at the bottom,indicating that the methane oxidizing bacteria have the optimal methane oxidation efficiency in neutral solution(i.e.,at pH value 7).When the solution reaches alkaline properties at pH value 9,the methane reduction rate of methane oxidizing bacteria is significantly lower than that at pH value 7.This suggests that the growth,reproduction,and metabolic activity of methane oxidizing bacteria are inhibited in an alkaline environment,leading to a decrease in the efficiency of biological methane oxidation.At a certain initial methane concentration,the oxidation efficiency of methane-oxidizing bacteria increases with the increase of initial methane concentration,but when the initial methane concentration exceeds a certain value,it inhibits the oxidation efficiency of
作者
李明玉
孙文静
丁梧秀
何朋立
王晓强
王艳红
LI Mingyu;SUN Wenjing;DING Wuxiu;HE Pengli;WANG Xiaoqiang;WANG Yanhong(School of Civil Engineering,Luoyang Institute of Science and Technology,Luoyang 471023,China;College of Environment Science and Engineering,Donghua University,Shanghai 201620,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2024年第10期239-246,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金项目(41977214)
河南省科技厅科技攻关项目(232102320098)
高校博士启动基金项目(2021BZ23)。
关键词
生物炭
微观结构
垃圾填埋场
甲烷氧化菌
甲烷降低率
biochar
microstructure
landfill
methane oxidizing bacteria
methane reduction rate
