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Indexed by:期刊论文

Date of Publication:2019-06-05

Journal:JOURNAL OF HAZARDOUS MATERIALS

Included Journals:SCIE、PubMed、EI

Volume:371

Page Number:463-473

ISSN No.:0304-3894

Key Words:Microbial electrosynthesis system; Extracellular polymer substance; Acetate production; Cd(II) removal; Hydrogen production

Abstract:The simultaneous production of acetate from bicarbonate (from CO2 sequestration) and hydrogen gas, with concomitant removal of Cd(II) heavy metal in water is demonstrated in multifunctional metallurgical microbial electrosynthesis systems (MES) incorporating Cd(II) tolerant electrochemically active bacteria (EAB) (Ochmbactrum sp. X1, Pseudomonas sp. X3, Pseudomonas deihiensis X5, and Ochrobactrum aruhropi X7). Strain X5 favored the production of acetate, while X7 preferred the production of hydrogen. The rate of Cd(II) removal by all EAB (1.20-1.32 mg/L/h), and the rates of acetate production by X5 (29.4 mg/L/d) and hydrogen evolution by X7 (0.0187 m(3)/m(3)/d) increased in the presence of a circuital current. The production of acetate and hydrogen was regulated by the release of extracellular polymeric substances (EPS), which also exhibited invariable catalytic activity toward the reduction of Cd(II) to Cd(0). The intracellular activities of glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and dehydrogenase were altered by the circuital current and Cd(II) concentration, and these regulated the products distribution. Such understanding enables the targeted manipulation of the IVIES operational conditions that favor the production of acetate from CO2 sequestration with simultaneous hydrogen production and removal/recovery of Cd(II) from metal-contaminated and organics-barren waters.