Anaerobic degradation of Zhaotong lignite by sulfate reducing bacterium Desulfotomaculum reducens ZTS1

Abstract:

[Objective] A SRB strain Desulfotomaculum reducens ZTS1 isolated from enrichment from coal mine water was used to anaerobically degrade Yunnan Zhaotong lignite, and the physicochemical properties of which before and after degradation with SRB strain were analyzed. [Methods] Mineral components, organic functional groups, surface morphology, pore structure changes of lignite minerals before and after anaerobic degradation with SRB were studied by proximate and ultimate analysis, X-ray diffraction, Fourier transform infared spectromotry, Scanning electron microscopy and low temperature liquid nitrogen adsorption method. [Results] After anaerobic degradation by D. reducens ZTS1, the ash and volatiles of lignite decreased slightly, the contents of carbon, nitrogen and sulfur decreased, while the content of oxygen increased. The sodium thiosulfate disappeared in the residual coal. FT-IR results showed that the methyl and methylene groups on the long chain hydrocarbon of lignite increased, while the free hydroxyl group decreased. With the increase of coal surface roughness, the pore size of small pore and the specific surface area of pore size Increases.[Conclusion] D. reducens ZTS1 can anaerobically degrade Zhaotong lignite, and change the physicochemical properties of the coal.

Key words:biogenic coal bed methane;sulfate reducing bacteria;lignite;anaerobic degradation;pores