LIU Fengjuan1,2, ZHANG Guoping2, FU Zhiping2, YU Lezheng1
(1. School of Chemistry and Life Science, Guizhou Education University, Guiyang, 550018, China;
2. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China)
Abstract: The growth state of sulfate-reducing bacteria (SRB) and the removal efficiency of arsenic and antimony by SRB were investigated, when each of sodium lactate, ethanol, molasses and vinasse was used as carbon source. Batch studies show that sulfate-reducing bacteria have the best physiological activity on sodium lactate, apparent physiological activity on ethanol but with a longer lag phase and hardly any biological activity in either molasses or vinasse media. After addition of acidic arsenic and antimony stock solutions, SRB of all media lost physiological activity because there are not enough alkalinity and sulfide produced by SRB during 12 hours to neutralize and precipitate acidic waste water. Though SRB lost physiological activity and there are minute quantities of sulfide (≤3.62 mg/L) in the media, 65.6% of total As and 89.7% of total Sb could be removed from lactate media; only 10.0% and 17.1% of total arsenic could be removed from the media with molasses or vinasse as carbon source but 81.2% and 97.3% of total Sb are removed in these media, respectively, and neither arsenic nor antimony is reduced distinctly with ethanol. Another batch test was performed that either lactate or ethanol that could apparently support SRB growth were used as carbon source and target elements stock solutions were supplemented into the media 48 hours after inoculation. The instantaneous concentrations of dissolved sulfide in the media with sodium lactate or ethanol are 70.73 and 18.58 mg/L before addition of arsenic and antimony, respectively. In this test, SRB could survive acidic stock solutions and finally could remove 97.8% and 98.4% of total antimony, 27.8% and 24.6% of total arsenic in sodium lactate media and ethanol media, respectively. Therefore, it could be concluded that molasses and vinasse need further performance optimization and ethanol offering its potential alternative to sodium lactate as carbon source for growth of sulfate-reducing bacteria, and removal efficiency of arsenic and antimony has close connection with their own chemical property and reaction media besides physiological activity of sulfate-reducing bacteria.
Keywords: sulfate-reducing bacteria; carbon source; removal; arsenic; antimony
EARTH AND ENVIRONMENT Vol.46, No.2, Tot No.322, 2018, Page 179-187
