Keywords: chemo-biological treatment, FGD, flue gas desulphurisation, sulphate reduction, alkaline scrubbing, elemental sulphur, transition metals, sulphide nanoparticles, nanotechnology, effluent treatment, wet scrubbing, flue gas emissions, fossil fuel fired power plants, microbial sulphate reduction, anaerobic packed bed bioreactors, bioremediation, wastewater treatment
A chemo-biological treatment of scrubbing water from power plants with recovery of value-added products
A chemo-biological approach for treating sulphate-rich effluent generated during wet scrubbing of flue gas emissions from fossil fuel fired power plants has been discussed. Microbial sulphate reduction was carried out in an anaerobic up-flow packed bed bioreactor (R1) using ethanol as carbon source. More than 90% of Total Equivalent Sulphate (TES) present in the effluent was reduced to sulphide at HRT of 17 h in the tested loading range of 0.58?3.10 kg SO4/m³/day. Mass balance revealed that more than 88% of sulphate reduced was present as dissolved sulphide (HS-) and while only 0.01% was present as H2S(g). The paper discusses the feasibility of converting both H2S(g) and HS- into value-added products such as elemental sulphur and metal sulphide nanoparticles, respectively. Since the amount of H2S generated is very low (0.01%), this paper also suggests recovery of dissolved sulphide from the R1 effluent, as transition metal sulphide nanoparticles.