Abstract: The effects and toxicity mechanism of xanthate collectors (ethyl xanthate, isopropyl xanthate, butyl xanthate, isoamyl xanthate) on the activity of bacteria (i.e., Acidithiobacillus ferrooxidans, LD-1) were investigated. It is shown that alcohols and CS2 produced by the reaction of xanthate collectors and sulfuric acid are toxic to LD-1 bacteria. This can decrease the oxidation activity of LD-1 bacteria. With increasing of xanthate molecular weight, the absorption properties and permeability of alcohols on the surface of bacteria become increasingly stronger. So the inhibition effect of alcohols on LD-1 bacteria becomes more and more strong. With increasing of carbon chain length, the amount of CS2 produced by the reaction of xanthate and sulfuric acid decreases gradually at the same dosage of xanthate. And so the inhibition effect of CS2 on LD-1 bacteria becomes more and more weak. Therefore, xanthate collectors with different length of carbon chain have different inhibition effects on LD-1 bacteria.

Key words: Acidthiobacillus ferrooxidans, xanthate collectors, toxicity mechanism, adsorption

摘要： 以分离于湖北某铜矿的嗜酸氧化亚铁硫杆菌LD-1菌株(At.f LD-1)为研究对象，首先得出了乙基黄药、异丙基黄药、丁基黄药、异戊基黄药4种黄药类捕收剂对At.f LD-1菌株活性的抑制规律，进而研究了这些浮选药剂对At.f LD-1菌株的毒害作用机理。结果表明，不同碳链黄药在酸性介质中与硫酸发生分解反应生成的醇和CS2均会引起At.f LD-1菌株氧化活性降低。醇类随着分子量增加，在菌体表面的吸附和渗透性能越强， 由醇类抑菌作用所造成的At.f LD-1菌株氧化活性的降低越来越明显；相同黄药药剂用量下，随着不同烃基黄药碳链的增长，与酸反应所生成CS2量的逐渐减小，对At.f LD-1菌株的抑制作用逐渐减弱。故在这两种物质共同影响下，造成了不同碳链黄药对菌种活性影响差异较大。

关键词: 嗜酸氧化亚铁硫杆菌, 黄药类捕收剂, 毒害机理, 吸附作用