Study on the desulfurization effect of sphingomonas sp. on high-sulfur coal from Dabaotou with surfactant assistance

The addition of surfactants can promote the growth of bacteria and the secretion of alkaline protease, enhance the adsorption capacity of bacteria on the surface of coal, and thus improve the biological desulfurization rate. Therefore, the effect of Sphingomonas sp.on the desulfurization effect of Dabaotou high-sulfur coal under the action of four types of surfactants was studied. The results showed that the surfactant sophorolipid (SL) and Triton X-100 (TR) showed the best biological desulfurization effect at the concentration of 1 200 mg / L. The desulfurization effect of sodium dodecyl sulfate (SDS) was better than that of LAS (sodium dodecyl benzene sulfonate) at the concentration of 1 000 mg/L, and rhamnolipid (RL) was better than SL at 600 mg/L. The total sulfur in coal samples treated with TR, RL, SL and SDS was 2.02%, 2.45%, 2.61% and 2.64%, respectively, which met the coal standard for mechanical industry (S≤3.5%). The four surfactants could improve the activity of alkaline protease, promote the growth of bacteria, and enhance the adsorption capacity of bacteria to coal samples. The order of strength was TR > RL > SL > SDS > control group. Sulfur form and XPS analysis showed that the addition of four surfactants improved the removal effect of Sphingomonas on organic sulfur in coal, and the removal rate was up to 86.1%. GC-MS analysis showed that the number of hydrocarbons, lipids and sulfur-containing organic compounds in ethyl acetate and petroleum ether extracts increased significantly.