通气对硫化铜矿生物浸出过程中自由细菌和吸附细菌群落动态的影响研究

生物浸出回收低品位硫化铜矿中的铜金属具有操作简单、低能耗、节约经济等优点，成为了近年来的研究热点。然而低品位硫化铜矿生物浸出效率低是其面临的主要问题之一。本文为了促进生物浸出效率，研究了强制通气条件下的低品位硫化铜矿生物浸出过程中的铜浸出率、细菌群落动态演替等特征。结果表明，适当的通气可提高细菌浓度和铜浸出率。在通气时间为4 h·d?1时，浸矿14 d后的细菌浓度和铜离子浓度最高，分别为7.61×107 个·mL?1和704.9 mg·L?1。实验可得，吸附细菌在浸矿过程的前7 d起着重要作用，而自由细菌则是在第8 d到第14 d占主导地位。这一现象主要是由于浸出过程Fe3+水解形成钝化层所致，抑制了吸附细菌与矿石的接触。同时，通过16S rDNA分析可知，Acidithiobacillus ferrooxidans和Acidithiobacillus thiooxidans对低品位硫化铜矿生物浸出过程具有重要影响。

Effects of forced aeration on community dynamics of free and attached bacteria in copper sulphide ore bioleaching

Bacterial community dynamics and copper leaching with applied forced aeration were investigated during low-grade copper sulphide bioleaching to obtain better bioleaching efficiency. Results illustrated that appropriate aeration improved bacterial concentrations and leaching efficiencies. The highest bacterial concentration and Cu2+ concentration after 14-d leaching were 7.61 × 107 cells·mL?1 and 704.9 mg·L?1, respectively, at aeration duration of 4 h·d?1. The attached bacteria played a significant role during bioleaching from 1 to 7 d. However, free bacteria dominated the bioleaching processes from 8 to 14 d. This phenomenon was mainly caused by the formation of passivation layer through Fe3+ hydrolysis along with bioleaching, which inhibited the contact between the attached bacteria and ore. Meanwhile, 16S rDNA analysis verified the effect of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans on the bioleaching process. The results demonstrate the importance of free and attached bacteria in bioleaching.