Remediation Of Acid Mine Drainage Using Immobilized SRB Sluge With Modified Corncob

This paper is based on the characteristics of acid mine drainage in our country that it has high SO₄^2-,Fe²⁺and Mn²⁺content and low pH value.By means of microorganism immobilization technology and combining modified corncob and sulfate reducing bacteria sludge organically modified corncob immobilized SRBsludgeparticles areprepared.And the features of the particles are studied by processing AMD.The main conclusions are as follows:?1?Single-factor experiments are conducted with factors of different modification time and different modification concentrations and evaluation indicators of COD release and SO₄^2-removal rate.Initially the modification time for the corncob is set to be 24h and the modification concentration of NaOH is 5%and the modification concentration of H₂O₂ is 1%.And it is found that the COD release is relatively low and SO₄^2-removal rate relatively high.?2?Combining single factor experiments,Preparation of the immobilized SRB particles is made using the L9?3⁴?orthogonal test,Eventually it is determined that the modification time for the corncob is 24h and the modification concentration of NaOH is 6%and the modification concentration of H₂O₂ is 1.5%after variance analysis and range analysis.On these conditions Modification of corncob is the best.?3?Using the orthogonal experiment modified corncob particles and unmodified corncob particles are prepared and comparative analysis of the kinetic model of the corncob particles Reducing SO₄^2-is made.Prediction results showed that the reaction process of the corncob particles reducing SO₄^2-relatively follows the first-degree kinetic reaction model.The reaction rate of modified corncob particles reducing SO₄^2-is higher than unmodified corncob particles reducing SO₄^2-.the kinetic model suggests that the reaction process of SO₄^2-is primarily the dissimilatory reduction of SRB and its reaction rate is affected by electron acceptors greatly.?4?Using the orthogonal experiment modified corncob particles and unmodified corncob particles are prepared and comparative analysis of the dynamic model of the corncob particles absorbing Mn²⁺is made.Prediction results showed that the reaction process of the corncob particles absorbing Mn²⁺relatively follows the pseudo-second-order kinetic model.The reaction rate of modified corncob particles absorbing Mn²⁺is higher than unmodified corncob particles absorbing Mn²⁺.the kinetic model suggests that the reaction process of Mn²⁺being absorbed is primarily chemisorption.?5?Using the orthogonal experiment modified corncob particles and unmodified corncob particles are prepared and comparative analysis of the dynamic model of the corncob particles absorbing Fe²⁺is made.Prediction results showed that the reaction process of the corncob particles absorbing Fe²⁺relatively follows the Elovich adsorption kinetic model.The reaction rate of modified corncob particles absorbing Fe²⁺is higher than unmodified corncob particles absorbing Fe²⁺.?6?Dynamic experiments shows that when using modified corncob particles to process AMD other than unmodified corncob particles,the reduction rate of SO₄^2-is higher which means that modified corncob particles can be utilized more efficiently by SRB for dissimilation.The removal rates of Mn²⁺and Fe²⁺are higher correspondingly which indicates that the internal structure changes and the decomposition of large molecules in modified corncob have a great influence on the removal rates of Mn²⁺and Fe²⁺.And the COD release is also lower and that suggests that the internal nutrients in the modified corncob can be used more efficiently by SRB?7?XRD and SEM analysis show that the chemical composition and the space structure have changed significantly after the reaction.Compared with unmodified corncob particles modified corncob particles have developed porosity and good permeability and can make it easier for material exchange inside and outside the particle system and so all these help to guarantee the nutrient substance for the growth of microorganism and the free movement of the product of metabolism.And that is good to accelerate the adsorption of particles and the catabolization of SRB.Therefore particles containing modified corncob can be better utilized as a coherent carbon source verifying the advantage of modified corncob as a coherent carbon source.Modified corncob can be of a good carbon source for SRB.Modified corncob immobilized particles have an ideal effect on processing AMD.It also shows that this method can play a role in future practice.