Study On SRB And CSB Coexistence System Treating High Concentration SO₄^2- Organic Wastewater

In the process of high-concentration organic wastewater treatment,anaerobic biological treatment is concerned by environmental protection workers at home and abroad because of its economic efficiency and energy recyclability.However,when there is a large amount of sulfate,the high concentration of sulfide produced by sulfate reduction will inhibit the activity of methanogens,making the anaerobic methanogen system unstable or even collapse.As for the treatment of sulfides produced by sulfate reduction,the input can be reduced by introducing appropriate amount of air into the anaerobic reaction to form a micro-aerobic environment compared with other traditional treatment methods such as"anaerobic+aerobic","anaerobic+precipitation"and so on.On this basis,the effect of volume load of sulfate on the reaction system under the condition of micro-aerobic was investigated in a self-made reactor.Removal of sulfide from micro-aerobic bio-reactor was study under 10,000 mg/L chemical oxygen demand?COD?of inlet water,with the sulfate volumetric loading 0.75,1.0,1.5 and 2.0 kg/?m³·d?,respectively.The experimental results show that when the molar ratio of O₂/S is 0.6-1,the reactor is sufficient to reduce the sulfides in wastewater and biogas to a low level under a sulfate volumetric load of 2 kg/?m³·d?.The removal rate of sulfate is 89%and60%of sulfur is recovered as biological sulfur.Tentatively,activated carbon?AC?as an adsorbent was modified in positively charged iron to adsorb bio-sulfur through electrostatic interaction,which makes the recovery of bio-sulfur simpler and more effective.In this study,AC was modified with trivalent iron to obtain iron modified activated carbon with a positive charge,and the bio-sulfur with a negative charge was adsorption?p H=7.0?.After iron-modified,the specific surface area of AC was form 32.4 m²·g^-1 to 65.0 m²·g^-1,and the zeta potential was 25.3 m V at p H 7.0.The XRD pattern of the iron-modified activated carbon?Fe AC?explained that the metal specie of iron was Fe₃O₄.It could be clearly seen that there was Fe₃O₄ on the surface of the Fe AC,and sulfur particles with a large particle size were adsorbed by the Fe AC on the SEM figures.EDS analysis showed that the sulfur atom content on the modified activated carbon before and after adsorption increased by 1.76%.And the XRD pattern of the bio-sulfur explained that the bio-sulfur was made up of S₈?91.444%?,C₃H₄N₂OS?1.491%?and CH₅N₃S?7.075%?.The zeta potential of bio-sulfur was-25 m V and the particle size was mainly distributed at the average diameter of 1935 nm at p H 7.0.