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摘要：本课题研究在LIX860、LIX84IC等羟肟类萃取剂分别污染生物浸出环境的情况下，嗜酸氧化硫硫杆菌的新陈代谢特征和浸铜行为。结果表明，在被萃取有机相污染的生长环境中，嗜酸氧化硫硫杆菌的生长明显变慢，且最高浓度降低。在研究含萃取剂LIX860污染影响生长的一组实验中，清洁体系中的细胞浓度在第72个小时的时候就达到了最大值8.4*107cell/mL，而含15% LIX860有机相污染时直到第168小时才达到最大值4*107cell/mL，证明萃取有机相可以抑制细菌的生长。在研究萃取有机相污染对嗜酸氧化硫硫杆菌浸矿的影响时，未受污染的体系中，细胞浓度在浸出28天时达3.8*107cell/mL，氧化还原电位在浸出28天过程中一直上升至到622 mv，而在含15% LIX860有机相污染的环境中，浸出28天时细胞浓度为2*107cell/mL，氧化还原电位上升到431 mv；在含15% LIX84IC有机相污染的环境中，浸出28天时细胞浓度为2.3*107cell/mL，氧化还原电位为392 mv。可以得清洁体系的氧化能力最好，浸铜能力最强，有萃取有机相存在时，浸出体系氧化能力减弱，浸铜能力下降。对比分析LIX860与LIX84IC的影响可知，萃取剂LIX84IC比LIX860对嗜酸氧化硫硫杆菌的毒性略大，抑制其浸铜能力作用更明显。以含5%萃取剂的有机相污染时的情况为例，萃取剂LIX860污染的浸出过程氧化还原电位在28天时高于LIX84IC污染的情况，从Fe3+/Fe2+的比值来看，LIX860污染的浸出过程的比值总体上比LIX84IC污染的大，尤其是在后期。52788
毕业论文关键词：微生物冶金；铜溶剂萃取；羟肟类萃取剂；嗜酸氧化硫硫杆菌；代谢
Influence of hydroxyoxime extractant on metabolic and copper leaching ability of Acidithiobacillus thiooxidans
Abstract: This paper focused on the effects of hydroxamic extractant like LIX860, LIX84IC on the metabolic characteristics and copper leaching behavior of Acidithiobacillus thiooxidans. Results showed that in the environment polluted by extraction organic phase, Acidithiobacillus thiooxidans growed more slowly, and the highest levels of cell numbers decreased. In a set of experiments on the growth of containing the extractant LIX860 pollution, the cell concentration in the controll case in the first 72 hours reached the maximum value of 8.4*107 cell/mL, while polluted by containing 15% LIX860 organic phase it took 168 hours to reach maximum of 4*107cell/mL. It is proved extraction organic phase can inhibit the growth of Acidithiobacillus thiooxidans. In the bioleaching process by A.t, the cell concentration of unpolluted system reached 3.8*107cell/mL at the bioleaching end of 28 days, oxidation-reduction potential in 28 days of bioleaching process has been increased to 622 mv, and in the environment polluted by 15% LIX860 organic phase, the cell concentration was 2*107cell/mL, oxidation-reduction potential was 431 mv; In the environment polluted by 15% LIX84IC organic phase, bioleaching of 28 days, the cell concentration was 2.3*107cell/mL, oxidation-reduction potential was 392 mv. The oxidation ability in the controll case is the best, the ability of bioleaching copper is the best. When the extraction of organic phase existed, the oxidation ability of the A.t is weakened, and the copper leaching ability decreased. Comparely analysising the effects of LIX860 and LIX84IC, it was known the toxicity of extractant LIX84IC to Acidithiobacillus thiooxidans was slightly larger, inhibiting to the copper bioleaching was more obvious. The oxidation-reduction potential of leaching system which contains 5% LIX860 was higher than the leaching syetem which was polluted by 5% LIX84IC in 28 days. From the point of view of Fe3+/Fe2+ ratio, the ratio in the system polluted by LIX860 was overall on the ratio of syetem polluted by LIX84IC in the leaching process , especially in the later.
Keywords: biohydrometallurgy; solvent extraction; hydroxyoxime extractant; Acidithiobacillus thiooxidans; metabolism