2种细菌降解蒙东褐煤产腐植酸的研究

Study on humic acid production from the degradation of Mengdong lignite by two kinds of bacteria

通过单因素实验和正交实验分别得到假单胞菌属和粪产碱杆菌降解蒙东褐煤提取生物腐植酸的最优条件,将此条件下所得的2种生物腐植酸与利用碱性萃取剂法得到的化学腐植酸通过UV-vis、FTIR、XPS及营养元素检测等方法进行对比分析。研究结果显示,假单胞菌属对蒙东褐煤氧化煤的最优降解条件为煤浆浓度0.5g/50mL、提取时间14d、菌液用量2mL/50mL,粪产碱杆菌对蒙东褐煤氧化煤的最优降解条件煤浆浓度0.5g/50mL、提取时间12d、菌液用量4 mL/50 mL,2种细菌对生物腐植酸的最高产率分别为35.39%和38.26%,这表明粪产碱杆菌对蒙东褐煤的降解效果好于假单胞菌属;对照组碱提取法对化学腐植酸最高产率为42.89%。UV-vis和FTIR分析表明,2种生物腐植酸的分子量、芳香度以及含氧官能团的总数量要小于化学腐植酸;XPS分析表明2种生物腐植酸中含氧官能团的种类数大于化学腐植酸,同时2种生物腐植酸中的碳元素的存在形式与化学腐植酸也有较大差异;营养元素检测表明2种生物腐植酸中的N、P、K、Ca、Mg的含量远大于化学腐植酸。

The optimal conditions for extracting biological humic acid from Mengdong lignite by Pseudomonas sp.and Alcaligenes faecalis were obtained through single-factor experiments and orthogonal experiments.The two types of biological humic acids obtained under these conditions were compared and analyzed with the chemical humic acids obtained by alkaline extraction method through UV-vis,FTIR,XPS,and nutrient element detection methods.The research results show that the optimal degradation conditions of Pseudomonas sp.for oxidized coal from Mengdong lignite are coal slurry concentration of 0.5 g/50 mL,extraction time of 14 d,bacterial liquid volume of 2 mL/50 mL,while the optimal degradation conditions of Alcaligenes faecalis include the coal slurry concentration of 0.5 g/50 mL,the extraction time of 12 d,and the bacterial liquid volume of 4 mL/50 mL;the highest yields of the two bacteria on biological humic acid are 35.39%and 38.26%,respectively,showing the better degradation effects of Alcaligenes faecalis on Mengdong lignite than that of Pseudomonas sp.;the highest yield of chemical humic acid by the alkali extraction method in the control group is 42.89%.UV vis and FTIR analysis show that the molecular weight,aromaticity and total number of oxygen-containing functional groups of the two biological humic acids are smaller than those of chemical humic acid;XPS analysis shows that the number of types of oxygen-containing functional groups in the two biological humic acids is larger than that of chemical humic acid,and the existence form of carbon element in the two biological humic acids is also very different from that of chemical humic acid;nutrient element test shows that the contents of N,P,K,Ca,and Mg in the two biological humic acids are much greater than those of chemical humic acid.