利用嗜酸性硫杆菌去除制革污泥中铬的研究

本研究采用嗜酸性硫杆菌(Thiobacillus ferrooxidans和Thiobacillus thiooxidans)并添加S粉为能源物的生物淋滤技术应用于制革污泥中铬的去除(溶出).序批式试验结果表明,淋滤处理8d,Cr的溶出率可高达100%(污泥中铬的原始浓度为14519mg/kg).在能源物各种投加比例中,以4g/L的投加比例较好.研究表明,生物淋滤法去除制革污泥中铬主要是通过嗜酸性硫杆菌的新陈代谢使介质酸化而实现的.生物淋滤作用导致介质pH下降到2.0,是使制革污泥中铬大量溶出的一个临界点,在pH低于这个临界点时,污泥中铬去除率才可迅速达到80%～100%.这为重金属含量高的废弃物处理展示了一条全新的途径.

Removal of Cr from Tannery Sludge by Acidophilic Thiobacilli

The removal of Cr from tannery sludge by bioleaching technology was reported in the paper. Batch experiments involved the inoculation of acidophilic Thiobacilli and addition of elemental sulfur as their substrate. Results showed that Cr removal of 100% could be obtained after 8 days of bioleaching. The oxidation of added sulfur by acidophilic Thiobacilli decreased sludge pH value which caused the solubilization of Cr from tannery sludge. A threshold pH of 2.0 existed for Cr solubilization from tannery sludge, below which Cr solubilization efficiency sharply increased to 80%-100%. This study might provide a newly attractive alternative for the treatment and disposal of heavy metal-contaminated solid wastes.