Bioremoval of arsenic and antimony from wastewater by a mixed culture of sulfate-reducing bacteria using lactate and ethanol as carbon sources

• Published in: International biodeterioration & biodegradation Vol. 126; pp. 152 - 159
• Main Authors: Liu, Fengjuan, Zhang, Guoping, Liu, Shirong, Fu, Zhiping, Chen, Jingjing, Ma, Chao
• Format: Journal Article
• Language: English
• Published: Barking Elsevier Ltd 01.01.2018; Elsevier BV
• Subjects: Antimony; Arsenic; Arsenic trisulfide; Bacteria; Bioremediation; Carbon; Carbon sources; Chemical elements; Coprecipitation; Ethanol; Iron sulfides; Lactic acid; Mixed culture; Precipitates; Sorption; Sulfate-reducing bacteria; Sulfates; Sulfides; Wastewater; Wastewater treatment; Water treatment; Antimony; Sulfate-reducing bacteria; Arsenic; Wastewater
• ISSN: 0964-8305; 1879-0208
• DOI: 10.1016/j.ibiod.2017.10.011

We investigated the remediation of wastewater containing As and Sb through the application of a mixed culture of sulfate-reducing bacteria (SRB). The effect of Fe(II) and different carbon sources on the removal of As and Sb was evaluated. The wastewater initially contained 5 mg L−1 of both As(V) and Sb(V), and the treatment was conducted over a 12-d period. The produced precipitates were characterized by TEM and XRD to elucidate the metalloid removal mechanism. In the absence of Fe(II), Sb was efficiently removed (97.6% and 97.8% with lactate and ethanol as carbon sources, respectively, hereinafter the same), whereas only a relatively small fraction (27.8% and 26.4%) of As was removed. The addition of 200 mg L−1 Fe(II) greatly improved the removal of As (78% and 98.2%) and further increased the removal of Sb (98.8% and 99.4%). We hypothesized that As was removed through sorption/co-precipitation by FeS instead of the formation of As2S3. The use of ethanol as a carbon source generated a relatively lower yield of sulfide compared to the use of lactate, but it resulted in a higher removal of As and Sb. This may be attributed to the low production of sulfide, which possibly resulted in the slow precipitation of FeS that enhanced the sorption/co-precipitation of ions. This work demonstrates the high application potential of ethanol as a carbon source and the addition of Fe(II) in the bioremoval of As and Sb from wastewater by SRB. •Arsenic was efficiently removed in the presence of Fe(II).•It was proposed that As was removed through sorption/co-precipitation by FeS instead of formation of As2S3.•The use of ethanol resulted in a higher removal of As and Sb compared to the use of lactate.•The relatively low production of sulfide favored the removal of As and Sb.