Effect Of Sodium Dodecyl Sulphate On Bioleaching Of Cd,Cu And Zn From Xiangjiang Sediment By Acidithiobacillus Ferrooxidans And Acidithiobacillus Thiooxidans

Cadmium（Cd）, Copper（Cu） and Zinc（Zn） as several common heavy metals due to its biological toxicity and migration capability, which can not be readily biodegradable in the human through food chain animals and plants. The heavy metal caused great harm to the health of animals and plants as well as the human body. Therefore, the control of pollution and remediation of soil heavy metals is an important problems to be solved. Compared with the conventi onal chemical and physical techniques, Bioleaching, a technology of applying thiobacillus to remediate contaminated soils, is generally considered as a low-cost, eco-friendly approach which has gained considerable interests worldwide. The technique of surfactant enhanced bioleaching efficiency as bioleaching derived its efficiency has been widely applied.The experiment is based on the sediment as research object, aiming at cadmium, copper and zinc, based on the biological leaching technology, introducd of surfactant（SDS） as exogenous additives. The research is to study the removal effect of Cd, Cu and Zn and the mechanism under the action of SDS. This paper mainly analyzes under the action of SDS, the change of p H, ORP, SO₄^2-, Fe²⁺ and DO. The main objective of the research was to investigate effect of SDS on bioleaching of Cd,Cu and Zn from Xiangjiang sediment by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. The main conclusions of the study were as follows :1、SDS is water soluble organic matter. It has a negative effect on the growth of thiobacillus. When adding a certain amount of SDS to medium, the sulfur oxide thiobacillus showed obvious biological toxicity, as the addition of SDS is more than 0.5 g/L, the toxicity becomes more and more obvious. As the species continue to develop,the sulfur oxide thiobacillus gradually adapt to the environment of SDS and begin to play the ability of sulfur oxide. In the learning process, p H and Fe²⁺dropped, ORP, SO₄^2- and DO rised.2、After the domestication of the native sulfur oxide sulfur bacillus in SDS,through study the influence of SDS on domesticated thiobacillus growth,it may could hance the hydrophilicity and dispersivity of elemental sulfur so that increase the contact area of bacteria and sulfur,improving the utilizability and availability of energy substances.3、 When the addition of SDS range from 0-0.5 g/L, heavy metal removal efficiency increased significantly, when the concentration of SDS is 0.6 g/L, the growth and proliferation of sulfur-oxidizing bacteria would be restrained, the indicators are in a state of decline. When the concentration of SDS is 0.5 g/L, the removal rate of Cd, Cu and zinc reach maximum value with 87.74%, 87.74% and 84.48% respectively.