The Migration And Hydraulic Conductivity Of Arsenic And Antimony In The Mining Area Under The Action Of Reductive Microorganisms

Pollution of arsenic and antimony has become a widely environmental problem,the toxicity of them is also very similar.In this paper,based on the mining area of two common anaerobic bacteria（SRB and JF-5）form FeS film layer in the surface of limestone,increasing the adsorbent surface area and adsorption performance,by using column experiment and batch test to study the As and Sb migration and competition behavior in FeS coated limestone,explore the mechanism of adsorption,package coated layer of internal change and coated the dissolution characteristics of limestone.In addition,this article preliminary using CXTFIT inserted in the column experiment content analytical CDE excel model to fitting the migration behavior of the As and Sb.The main results were as follows:1.Biological FeS coated limestone adsorption amount of As and Sb,and biological FeS cladding is higher than growth,the increase of the adsorption quantity decays with the growth of the coating amount.Using CXTFIT into CDE model of excel can better simulate migration behavior of As and Sb in the coated limestone,and got a parameter range Rλ=（1.00 e+00 e+06,1.00）.2.The relationship of Biological FeS adsorption rate,adsorption quantity and occupy station of As and Sb are: V_As > V_Sb,Q_As > Q_Sb,W_As < W_Sb.Relative to shorter adsorption time（24 h）,a long time（48 h）adsorption of pure limestone and FeS coated limestone of the As adsorption quantity increases by about 1 times and three times respectively.3.As⁵⁺ and Sb⁵⁺ have produced reduction in the process of bio nano-FeS adsorption,and chemical adsorption behavior exists in this pricess.4.FeS coated limestone dissolution process,The pH of pure limestone,coated with 2d and 7d were 6.4,5.0,4.7,it shows that bio-FeS layer significantly inhibits the dissolution of limestone,and can reduce the final pH 1.5 units.5.Different thickness of coating layer on limestone dissolving ability of initial block is different,the pH of coated dissolve 1 h C1（coated 3 days）and C2（covering 7 days）were 3 and 5,respectively.This proof that the thicker the coating layer has a stronger blocking effect on dissolution ability.6.According to the first law of Frick,biological FeS coated limestone dissolution model available formula A t^1/2-n_Ca,gypwas described,and it is concluded that the amount of secondary mineral precipitation of Ca,n_Ca,gyp n is C₀ = 19.5,nC₁ = 11.3,nC₂ = 16.8 respectiely.