A Technical Research On Sulfide Microbial Oxidation Process Of Bio-FGD Absorbed Residue

Sulfur dioxide(SO₂) is one of the major constituents that cause acide rain. Treatment of SO₂ in exhaust has been a hot point in environmental engineering.Biological flue gas desulfurisation technology is as a new regeneratable FGD technology that can achieve contaminant treatment and resources recycle. This process combines a conventional caustic scrubber for the removal of SO2 from flue gas and two biological reactors for processing the liquid from the absorber. In the two biological reactors, one anaerobic and one aerobic, treat the absorbed liquid. In bio-reactor, the sulfite and sulfate in absorbed liquid first transforms to sulfite and later elementary Sulfur, while the caustic cleanser regenerated and recycled.This paper describes the research on the aerobic treatment process of sulfide absorbed residue after anaerobic biological reactor. Using a bio-contact oxidation reactor with stream-folded clapboard and 3D elastic filler as carrier, the changing rate of sulfate, sulfuric acid, COD, H₂S and pH in waste liquid according to different aeration quantity and HRT is reviewed.And experimental outcome shows that there is a best value for COD-removing rate, desulfating ratio and formation of sulfuric acid generating corresponded to different aeration quantity. However, when HRT is 12 hours and aeration quantity is 0.7m³/L, outlet COD from biofilm reactor can be 120～250mg/L, COD-removing rate is remarkable 85～90%, water discharge consistency of sulfuric acid is 50～60mg/L, desulfating ratio is approximate 90%, which achieves 2^nd level of...