pH对生物炭改性土甲烷氧化速率的影响

Effect of pH on Methane Oxidation Rate of Biochar Modified Soil

为提高垃圾填埋场生物覆盖层的微生物甲烷氧化能力,本文通过培养瓶试验与土柱试验研究了pH对水稻秸秆生物炭改性土的微生物甲烷氧化速率的影响。结果表明,生物炭是碱性材料,降低生物炭改性土的pH能显著提升其甲烷氧化性能,当生物炭改性土(炭掺量20%)的pH从10.4降低到5.8时,其甲烷峰值氧化速率是初始值的5倍。土柱尺度下,pH=5.8时的稳定甲烷氧化速率是pH=10.4时的5.5倍。这是由于弱酸性下生物炭改性土中甲烷氧化菌与甲烷单加氧酶的活性最高。受土柱堆积情况与空气流通影响,土柱上部的甲烷氧化速率高于下部,大尺度下的甲烷氧化速率明显小于小尺度。

In order to improve the microbial methane oxidation capacity of landfill bio-cover,the effect of pH on the microbial methane oxidation rate of rice straw biochar-modified soil is investigated in this paper by incubation bottle test and soil column test.The results show that biochar is an alkaline material,and lowering the pH of biochar modified soil can significantly improve its methane oxidation performance,when the pH of biochar modified soil (charcoal doping 20%) is reduced from 10.4 to 5.8,the peak methane oxidation rate is 5 times higher than the initial value.The stable methane oxidation rate at pH=5.8 is 5.5 times higher than that at pH=10.4 at the soil column scale.This is due to the highest activity of methane oxidizing bacteria and methane monooxygenase in the biochar modified soil under weak acidity.The methane oxidation rate in the upper part of the soil column is higher than that in the lower part due to the stacking condition and air circulation,and the methane oxidation rate in the large scale is significantly smaller than that in the small scale.