First insight into indigenous microorganisms in coal slurry involved in polyacrylamide biodegradation

Abstract

Indigenous microorganisms can affect coal slurry settling by polyacrylamide biodegradation; however, they have rarely been examined in detail. In this study, the microbial community composition in coal slurry was explored using 16S rDNA, and the microorganisms are assigned to 34 phyla and 98 genera. The predicted function results show that microorganisms in coal slurry are closely related to the organic matter biodegradation. To prove it, the Sphingomonas was isolated from the coal slurry, which was used to biodegrade polyacrylamide in coal slurry, and the biodegradation rate reached 66.4 % within 76 h. The results of SEM, AFM, UV spectrometry, FTIR, and HPLC explain that the high molecular weight polyacrylamide is degraded into the smaller molecular weight organic products in the biodegradation process, and the coal slurry settling tests reflect that the settling rate and settling layer height are obviously inhibited by polyacrylamide biodegradation.