氮和磷对生物滴滤塔净化煤矿乏风瓦斯的影响

Effects of Nitrogen and Phosphorus on the Filtration of Coal Mine Ventilation Methane with Biotrickling Filters

研究了氮源类型和浓度以及磷元素浓度对生物滴滤塔净化极低浓度CH4的影响。利用空气和高纯CH4混合气模拟煤矿乏风瓦斯,生物滴滤塔填料为陶瓷鲍尔环,以实验室分离筛选到的甲烷氧化菌进行接种挂膜。结果表明,进气流量为2 L·min^1,喷淋液流量为0.1 L·min^1,进气CH4浓度在0.1%~1.1%,以Na NO3为氮源时,生物滴滤塔净化CH4的效果最好,优于（NH4）2SO4和NH4NO3为氮源时的表现。喷淋液中Na NO3浓度为70 mmol·L^-1,进气CH4浓度为0.1%~1.1%时,生物滴滤塔的CH4去除负荷为10.67~39.72 g·m^-3·h^-1,去除负荷随CH4浓度增加而增加;CH4净化率为97.92%~39.70%,净化率随CH4浓度增加而下降。在最佳氮源条件下,进气CH4浓度为0.9%,P元素浓度为100 mmol·L^-1时,滴滤塔CH4去除负荷最大为49.69 g·m^-3·h^-1,CH4净化率60.90%。

The effects of nitrogen source and phosphorus concentration on bioconversion of low concentration methane were analyzed in a biofiltration system. Ceramic Pall ring was used as the packing material and air/pure methane gas mixtures were used to simulate coal mine ventilation air methane（VAM）. A biotrickling filter was inoculated with methanotrophic bacteria which had high methane bio-oxidation efficiency. The biotrickling filter（BTF） was operated at conditions of gas flow rate 2 L？min？1, nitrate salts medium（NSM） nutrient solution spray rate 0.1 L·min^-1, inlet methane concentration 0.1%~1.1%. When the nitrogen source in NSM is Na NO3, the methane elimination capacity（ECMet） is higher than（NH4）2SO4 and NH4NO3. The optimum condition is Na NO3 concentration 70 mmol·L^-1, inlet methane 0.1%~1.1% which corresponds to an ECMet of 10.67~39.72 g·m^-3·h^-1. ECMet increases with inlet methane concentration but methane removal efficiency（REMet） decreases from 97.92% to 39.70% with the increase of inlet methane. The best BTF performance was obtained with Na NO3 70 mmol·L^-1, P 100 mmol·L^-1 and inlet methane concentration 0.9%, with maximum ECMet and REMet values of 49.69 g·m^-3·h^-1 and 60.90%, respectively.