| A highly heavy metal-resistant bacteria strain was screened from the soil of Tonglv mining area in Daye suburb.The influence of the bacteria strain on the adsorption of Cu2+ and Cd2+ ions by red soil colloid, cinnamon soil colloid, goethite and kaolin with different pH and amount was studied. A study of adsorption mechanisms of Cu2+ and Cd2+ on soil colloids ,clay minerals and bacteria cell has been carried out through FT-IR.The main results were shown as follows:1. The maximum adsorpion capacity(MAC) of Cu2+ by red soil colloid , cinnamon soil colloid, goethite and kaolin increased in the presence of bacteria NTG-Ol.The more amount of bacteria cells ,the greater MAC of Cu were.While the amount of bacteria cells increased from 6.5 X109 to 1.3X1010,the MAC of Cu2+ added to 62, 70, 89.5, 104.3, 76.7, 82.1 and 38.7, 49.6mmol/kg and the increasing rates werel4%, 27%, 9.6%, 27.7%, 5.6%, 13.3% and 23.5%, 58.2%.The effect of bacteria NTG-01 on the adsorption capacity of Cu2+of kaolin was the most remarkable of them.Compared with the non-bacterial system,the MACof Cd2+ by them in the presence of bacteria increased by 4.9, 12.8,5.4,7.1,13.4, 17.3 and 3.5,4.5mmol/kg and the increasing rates were 11.6, 30.4, 9.6, 12.7, 28.2, 36.6, 13.8, 16.3%.The influence on the adsorption capacity by the amount of bacterial cells was mainly concerned with the immobilizition of Cu2+and Cd2+ by bacterial cell and the interaction between soil colloids and bacteria.2. The adsorption percentage of Cu2+ by bacteria increased with the rise of pH value.When pH value is more than 6,the adsorpion percentage was close to 100%. The adsorpion percentage of Cd2+ by bacteria was highest at pH5.5. The adsorpion percentage decreased a little when the pH value is higher.Bacteria made the curves of Cu2+ adsorption percentage VS. pH for red soil colloid, goethite and kaolin shift to the lower pH side ,the range was 0.1-0.4 pH unit respectively. Little change was found for the curves of cinnamon soil colloid in the presence and absence of bacteia. As the addition of bacteria ,the curves of red soil colloid, cinnamon soil colloid, goethite shifted to the lower pH side,the shifted range was 0.1-0.8 pH unit respectively.When pH value is less than 7,the relative position of curve of Cd2+ adsorption percentage V.S. pH of kaolin in the presence of bacteria shifted to higher pH side,when pH value is more than 7 ,the curve shifted to the lower pH side .The shifted range of the curves of goethite was the largest of them.As the addition of bacteia,the pH50 value of Cu2+ adsorped decreased 0.3-0.6 pH unit ,the pH50 value of Cd2+ adsorped decreased 0.2-0.8 pH unit.The results showed that the existance of bacteria NTG-01 increasedthe affinity for Cu2+ and Cd2+ in soil colloid,minerals systems and made them absorbed under the lower pH value.3. Before and after the addition to bacteria NTG-01,the kinetics process of Cu2+ adsorption in red soil colloid and cinnamon soil colloid systems could preferably be described by parabolic diffusion equation .Namely,the reaction velocity is depended on the number of surface adsorption sites.In the presence of bacteria NTG-01,the adsorption of Cd2+ on red soil colloid and cinnamon soil colloid could be illuminated by both first order reaction function and parabolic diffusion equation,but the former is better than the latter. Namely,the concentration of heavy metal mainly controlled the reaction rate.Within eighty minutes,little difference of adsorption velocity and amount of Cu2+ existed in the red soil colloid, cinnamon soil colloid and their composites, but the adsorption rate and amount of Cd2+ of the composites is much than the red soil colloid and cinnamon soil colloid obviously.4. Cu2+ mainly interacted with the free Hydroxyl group on the bacteria cell surface and the FT-IR spectrum picture of bacteria cell changed unobviously after the adsorption of Cd2+.Bacteria increased the interation between Cu2+ and the free Hydroxyl group on goethite surface.The reaction between Cd2+ and the hydrate hydroxyl group on go...
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