Study On Environmental Microbial Toxicity Effect Of Antimony And Antimony Fixation By Mixed Reducing Bacteria

With economic development,antimony?Sb?,a typical amphoteric metal element,is widely used in actual industrial production,and its mining volume and usage are gradually increasing.As a"by-product"in the mining process of antimony and other metals-tailings pond,the pollution caused by antimony is extremely serious.Also,antimony as a heavy metal is very toxic and seriously affects the biological activity in the environment.Because of its serious pollution and toxicity,antimony pollution control research has gradually been excavated.This article takes antimony as the research target heavy metal,explores the antimicrobial toxicity effect of antimony in the soil and water body around the tailings reservoir,and uses sulfate reducing bacteria to treat antimony pollution.The main findings are as follows:The content of heavy metals represented by antimony in the soil around the tailings pond exceeded the standard seriously,and the target pollutant antimony in corn and rice fields exceeded the national standard by more than three times,causing serious pollution.In the correlation study of heavy metal content,soil physical and chemical properties,and soil activity,there was no correlation between soil microbial activity and heavy metal content.Therefore,while investigating the activity of the soil,it is not enough to pay attention to the effects of heavy metals such as antimony in the soil.In some areas,it is necessary to pay attention to the effects of organic pollutants.The level of antimony pollution is relatively high,so in the following experiments,researchers used a mixed reducing flora composed by sulfate-reducing bacteria as functional bacteria to deal with antimony pollution.By measuring the growth curve,microcaloricity,and catalase activity of the mixed reducing bacteria at different concentrations of Sb???,the study found that with the concentration of Sb???increased,the activity of the mixed reduced bacteria decreased a lot.At the same time,the efficiency of Sb???treatment by bacteria groups decreases.Through correlation analysis,we have also found that the treatment efficiency of mixed reducing bacteria is closely related to the trace thermal activity,which provides a correlation for the activity of the mixed reducing bacteria to immobilize heavy metals.Based on the single-factor experiment,the surface response experiment further explores the optimal conditions for the maximum efficiency by mixed reducing bacteria to immobilize heavy metals,and finally found that when the pH was 7.22,the temperature was 33.44?,and the initial concentration of Sb???was 16.89 ppm,the treatment of Sb???could get best effect.Under the optimal conditions,the method of fixing Sb???by mixed reducing bacteria is divided into three parts:bacterial redox,self-adsorption of bacteria,and adsorption of extracellular polymer?EPS?by bacteria.Three major approaches contribute to the reduction of Sb???content,but for the experimental flora,the initial fixation efficiency was mainly contributed by the adsorption of heavy metals by the bacteria and extracellular polymers.As the number of days increased,the redox effect by sulfate reducing bacteria played a major role in fixing Sb???.On 7^th day,its redox contribution contributed more than 60%of the amount of fixed Sb???.