Study On Treatment Of Simulated Wastewater Containing Sulfide By SBR Process

The wastewater from dyes,pharmaceuticals,pesticides,petrochemical and other industrial process usually contains sulfide,which is corrosive and toxic to aquatic organisms.Furthermore,odor gas containing H₂S will be easily produced from sulfide,resulting in serious environmental pollution.Therefore,it is meaningful to remove sulfide by aerobic biological treatment which could turn the sulfides into elemental sulfur or sulfate.Sequencing batch reactor?SBR?is an intermittent operating bioreactor.And the process has so many advantages such as strong resistance to shock loading,small floor space,low cost of equipment and operation management.This paper mainly focused on the treatment characteristics of SBR for treatmenting the simulated wastewater containing sulfide.The temperature,aeration rate and pH on the treatment effects were investigated.Moreover,the correlations between sulfide oxidation and operating parameters?ORP,pH and DO?were analyzed.Firstly,the SBR reactor was inoculated with the aerobic activated sludge from a pharmaceutical factory wastewater treatment station.And it was successfully started up within 47 days.When the influent sulfide concentration was 400 mg/L and the aeration rate was 90L/h,the maximum elimination capacity of the reactor reached 1.2¹.5 kg S/?m³?d?.The sulfide removal efficiency and the elemental sulfur accumulation rate were impacted by aeration,temperature and pH.When the ORP value ranged from-350±10mV to-250±10mV,the temperature was 30?and pH ranged from 6 to 7 by controlling aeration,elemental sulfur was produced stably in the reactor.High-throughput sequencing analysis showed that the dissolved oxygen was the most important factor for the community structure change,next came temperature and pH.Then,the variations of ORP,pH and DO for sulfide oxidation in the SBR were analyzed.The results showed that there were two inflection points during the sulfide oxidation,and the highest sulfur concentration was occurred in the plateau region between these two inflection points.And these two feature points were nearly unaffected by the influent concentration,temperature and aeration flow;pH curve had two feature regions,namely a plateau region and a subsequent rapid degradation region,and the highest sulfur concentration was occurred in the area between these two feature regions.And these two feature regions were also nearly unaffected by the influent concentration,temperature and aeration;When all the sulfides were transformed into sulfate,the only inflection point appeared in the DO curve.Therefore,using ORP and pH value as sulfide oxidation control parameters in the SBR is feasible,which is conducive to the oxidation of sulfide to sulfur and waste recycling.