生物滴滤塔共代谢降解间二甲苯的性能及微生物群落分析

To construct a co-metabolic system and enhance the biodegradation of m-xylene in a biotrickling filter, the interaction between m-xylene and toluene under varying mixing ratios was explored. The performance and microbial community structure and function were analyzed in this study. The inlet concentration of toluene was maintained at about 250 mg / m³ , and the ratios of toluene and m-xylene were 1∶ 1, 1∶ 2, 1∶ 4, and 1∶ 6. The results indicated that compared with the performance of single m-xylene removal, the biodegradation was improved when toluene and m-xylene were mixed with the ratios of 1 ∶ 1, 1 ∶ 2, and 1 ∶ 4, especially when the radio was 1∶ 2, the removal efficiency (RE) of m-xylene was increased from 87. 22% to 96. 61%, and biodegradation was inhibited when the ratio was 1: 6. The changes in biomass showed that toluene was used as a growth substrate, providing carbon and energy sources for microorganisms, promoting the growth of microorganisms and the formation of biofilms, and thus stimulating the generation of microbial co-metabolism. In the process of co-metabolism, the abundance of microorganisms was increased and the microbial degradation ability was improved. In the whole biodegradation process, bacteria played an important role and Proteobacteria were the most dominant phylum, which was capable of efficiently removing m-xylene and toluene. At the genus level of bacteria, the abundance of Burkholderia and Mycobacterium increased during co-metabolism, especially Burkholderia increased from 7. 11% to 21. 94% . The PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) showed that among the primary metabolic pathways, the functional genes of Metabolism accounted for more than 50% and increased rapidly during the co-metabolism process, ranking second with a growth rate of 19. 86% . Among the secondary metabolic pathways, the functional genes of Amino Acid Metabolism accounted for the largest proportion, followed by Carbohydrate Metabolism, and Xenobiotics Biodegradation and Metabolism, which were favorable for co-metabolic biodegradation of m-xylene.