Enhanced organic compounds utilization and desalination of coal-fired power plant FGD wastewater by mixed bacterial sulphate reducing consortium

Abstract

Flue gas desulphurization (FGD) wastewater from coal-fired power plant contained sulfate, halogens, metals, metalloids and organics, which led to serious corrosion and environment pollution. For establishing intensive treatment of FGD wastewater, a mixed bacterial sulfate reducing consortium (MBSRC) was obtained from strain BY7 and SR10 sulfate reducing bacteria (SRB). Intensively removal of SO42− (99 %), metals and metalloids (88–100 %), organics (97 %), F- (100 %) and Cl- (88 %) were achieved. Sulfate loading rate reached 0.71 kg SO42−/m3 d in the MBSRC reactor. In comparison with treatment of FGD wastewater by single strain SRBs, enhanced removal of organics, F- and Cl- (up to 58 %) were achieved by MBSRC. Since associative degradation of refractory organic compounds, only 4 out of 25 organics in FGD wastewater were residually detected after biotreatment by MBSRC, while at least 12 organics were existed after biotreatment by single strain SRBs. Intensively utilization of organics by MBSRC led to higher growth rate and cell density in the reactor, which enhanced biosorption of F- and Cl- consequently. Thus, this study established an potential biotechnology for FGD wastewater recycling.