外源产甲烷菌降解褐煤产气实验

Experiments on the gas production of brown coal degraded by exogenous methanogens

为研究外源菌降解褐煤产气能力,从厌氧消解污泥中提取产甲烷菌群,以褐煤为碳源进行菌种驯化,开展产气实验,并对驯化后菌群的产气影响因素进行实验研究。驯化实验发现:驯化后该菌群初始产气时间由驯化前的12 d缩短为6 d,且30d内产气总量增加了29.2%;经检测,生成气体主要为CH4和少量CO2,未检测到重烃气。产气影响因素实验表明:该菌群最佳产气初始培养基pH值为7.0,产气量分别约为初始pH值为6.4、7.4时的1.9倍和2.4倍;煤的粒径也是影响产气量的因素之一,表现为粒径越小,产气量越大,但产气量随粒径变小变化不明显;培养基本身产气量约占总产气量的50%,原因可能是其中添加了微量L-半胱氨酸(0.5g/L)和酵母浸出液(1 g/L)。

To investigate the ability of exogenous bacteria to degrade brown coal,methanogens were enriched from anaerobic sludge and domesticated using brown coal as the single carbon source.After domestication,the lag time of initial gas production is shortened from 12 to 6 days and the CH4production increases by 29.2% in 30 days.The generated biogas is composed of CH4and a little CO2,no heavy hydrocarbons are detected.Experiments on gas production influencing factors demonstrate that the best initial pH for the culture medium is 7.0 and the maximum gas production is 1.9 times and 2.4 times higher than that at pH 6.4 and pH 7.4,respectively.The particle size of coal is one of factors influencing the gas production： the general trend is the smaller the particle size,the bigger the gas production,but the variation of gas production is not significant with decreasing particle size.Gas produced by the culture medium accounts for around 50% of the total gas production and it is likely caused by the addition of L-cysteine（0.5 g/L） and yeast extract（1 g/L） to the medium.