煤泥厌氧发酵转化生物甲烷的影响因素分析

Analysis of influencing factors of biological methane production with coal slime by anaerobic fermentation

煤泥是选煤厂洗选的尾矿,因储量巨大,具有水分、灰分高、热值低等特点,难以被处置,常被当作一种废弃物随意堆放,由此造成土地资源的浪费和环境的污染。为拓宽煤泥的利用途径,实现资源利用和环境保护,对煤泥厌氧发酵转化生物甲烷的影响因素进行分析。选取内蒙古锡林郭勒盟矿、山西燕子山矿和马兰矿、河南赵固一矿选煤厂的煤泥,以实验室驯化的菌液为菌种来源,通过生物产气模拟实验、红外光谱、荧光光谱、16S rRNA测试来分析不同煤泥产气差异的影响因素。结果表明:不同煤泥生物产气能力不同,产气受制于煤变质程度和有机质含量,煤阶越低且有机质含量越高,煤泥的产气效果越好,反之,则相反;低变质程度煤泥经微生物降解后,煤中脂肪结构、羟基、氨基等各类基团更易脱落,芳香类物质部分被转化为小分子量物质,与高变质程度煤泥相比更容易产气;低变质程度煤泥中的蛋白质类有机质被微生物分解较多,产气较好,而高变质程度煤泥含有较多不易降解的腐殖质类有机质,产气效果差。不同煤泥菌群组成差异性较小,细菌多样性高于古菌,细菌以假单胞菌、拟杆菌属为主,古菌以甲烷粒菌属、甲烷丝菌属为主。煤泥转化生物甲烷受细菌影响较大,优势细菌菌属对前期有机质降解起关键作用,生物甲烷主要来源于甲烷粒菌属对CO_(2)和H_(2)的转化利用。研究结果揭示了不同煤泥产气差异的原因,并为建立煤泥转化生物甲烷的潜力评价方法提供参考。

Coal slime is the tailings of coal preparation plant.It is difficult to dispose because of its huge amount,high moisture,ash and low calorific value.Coal slime is often dumped as a waste,resulting in a waste of land resource and environmental pollution.In order to increase the utilization of coal slime,realize an efficient utilization of resource and protect the environment,the factors influencing the conversion of coal slime into biomethane were explored.The coal slimes from the coal preparation plants of Xilinguole League Mine in Inner Mongolia,Yanzishan and Malan Mines in Shanxi and Zhaogu No.1 Mine in Henan were selected,and the domesticated bacterial liquid was used as the source of bacteria.The influence factors of gas production of different coal slimes were analyzed by biological gas production simulation experiment,infrared spectrum,fluorescence spectrum and 16 S rRNA tests.The results show that the biogas production capacities of coal slimes are different,and the biogas production is controlled by the metamorphism grade of coal and the content of organic matter.The lower the coal rank of coal slime and the higher the organic matter content,the better the gas production effect of coal slime is,and vice versa.After the microbial degradation of low rank coal slimes,various groups such as aliphatic structure,hydroxyl and amino in coal are easier to fall off,and the aromatic compound are partly converted into small molecular-weight substances,which are easier to produce gas than high rank coal slime.The protein organic matter in low metamorphic coal slimes are decomposed more by microorganisms,and the gas production effect is better,while the high metamorphic coal slime contains more humus organic matter,which is not easy to degraded,and the gas production effect is poor.The diversity of bacteria is higher than that of archaea.The bacteria is mainly consisted of Pseudomonas and Macellibacteroides,whereas the archaea is mainly consisted of Methanocorpusculum and Methanothrix.The biogas from coal slime is affected by bacteria,and dominant bacteria plays a key role in the degradation of organic matter in the early stage.The biomethane mainly comes from the conversion and utilization of CO_(2)and H_(2)by methanogens.The results reveal the reasons for the difference in the gas production from different coal slimes,and provide a reference for the establishment of a potential evaluation method for coal slime to convert biomethane.