氧化硫硫杆菌JJU-1生物淋滤去除污泥中的重金属

将前期分离得到的嗜酸性氧化硫硫杆菌JJU-1（Thiobacillus thiooxidans JJU-1）接种于污水处理厂污泥中，进行为期7 d的生物淋滤实验，对淋滤过程中的pH值、氧化还原电位（ORP）和重金属去除率进行检测。研究结果表明：氧化硫硫杆菌JJU-1不同接种量处理浸出液的pH下降幅度不同，当接种量为15%时，浸出液pH下降最快，其ORP达到最大值（444 mV），Cu、Cd和Pb的去除率分别高达79.2%、96.6%和93.4%。添加能源物质S可以明显降低淋滤液的pH，当能源物质S投入量增加到12 g·L-1时，淋滤7 d后，浸出液的pH下降至1以下，浸出液的ORP在S添加量为16 g·L-1时达到最大值（477 mV），20 g·L-1 S粉添加量条件下，Cr、Cu和Pb的去除率最大，分别为98.8%、74.3%和85.8%；然而，添加能源物质S对Cd的浸出无明显影响。以上研究结果表明，氧化硫硫杆菌JJU-1在去除污泥中重金属方面有着广阔的前景。

Bioleaching of heavy metal from sewage sludge by Thiobacillus thiooxidan JJU-1

In order to investigate the effect of Acidithiobacillus thiooxidans on bioleaching of Cd, Cr, Cu and Pb-rich sludge, Acidithiobacillus thiooxidans JJU-1 was inoculated to sludge from a sewage disposal plant through flasks experiments for 7 days. The pH value, ORP (oxidation reduction potential) and the respective removal rates of bioleaching of the sludge were tested. The results showed that the descending range differed in different amounts of inoculums of JJU-1.The pH value decreased by the highest descending range and the ORP reached the maximum of 444 mV with the sludge-inoculation ratio of 15%. As high as 79.2% of Cu, 96.6% of Cd and 93.4% of Pb could be leached for 15% of sludge-inoculation ratio. In addition, the energy source of sulfur significantly reduced the pH value of sludge. The pH value declined to less than 1 with 12 g·L-1 of sulfur after 7 days of bioleaching. The ORP exhibited the maximum of 477 mV with 16 g·L-1 of sulfur. The maximum removal rate of Cr, Cu and Pb were 98.8%, 74.3% and 85.8% with 20 g·L-1 of sulfur, respectively. However, the addition of sulfur did not affect the leaching rate of Cd. These results demonstrated the potential of Acidithiobacillus thiooxidans JJU-1 for the bioextraction of valuable metals from sludge.