生物淋滤结合类芬顿反应去除底泥中重金属  

Removal of heavy metals from sediment by bioleaching combined with fenton-like reaction

作　　者：揭诗琪 邵继莹 吴雨桐[1] 李佳宇[1] 张丹[1] 朱建裕[1,2] 

机构地区：[1]中南大学资源加工与生物工程学院,长沙410083 [2]中南大学生物冶金教育部重点实验室,长沙410083

出　　处：《有色金属科学与工程》2016年第1期108-113,共6页Nonferrous Metals Science and Engineering

基　　金：国家自然科学基金资助项目(51174239);中南大学学生自由探索项目(2282014bks145)

摘　　要：结合Acidithiobacillus ferrooxidans生物淋滤与类芬顿反应以高效除去污染底泥中重金属.研究了15 d生物淋滤周期中p H值和ORP的变化,以及重金属Cu,Zn,Pb和Cd的去除情况.经过2 d生物淋滤处理后,反应体系p H值下降到2.5左右,此时向体系中加入5种不同剂量的H_2O_2(1 g/L,3 g/L,5 g/L,7 g/L,9 g/L),反应3 h完成类芬顿反应.结果表明,生物淋滤过程中p H值呈现下降趋势,从5.0降低到2.0左右,并维持在2.0附近波动.ORP从250 m V上升到700 m V附近,然后保持在700 m V左右.污染底泥经过15 d生物淋滤后,重金属去除率分别为:Cu为52.1%,Zn为65.8%,Pb为42.5%,Cd为83.25%.然而2 d生物淋滤加3 h类芬顿反应的最大金属去除率达到:Cu为59.8%,Zn为70.0%,Pb为52.7%和Cd为85.3%.实验表明该方法可以提高重金属的去除率,并大大缩短反应时间,从而提供了一种相对高效的去除底泥中重金属的方法.Feasibility of bioleaching by A cidithiobacillus ferrooxidans combined with Fenton-like reaction to efficiently remove heavy metals from contaminated sediment was investigated. The variation of pH and ORP d uring the 15 d bioleaching and the removal of heavy metal Cu, Zn, Pb and Cd were studied. After 2 d bioleaching, the reaction system pH decreased to approximately 2.5, then added five different dosages of H2O2 （1, 3, 5, 7, 9 g/L） into the system to complete the Fenton-like reaction for 3 h. The results show that the pH presents a downtrend during the 15 d bioleaching, and decreases from 5.0 to 2.0,then keep stable approximately at 2.0. However, ORP increases from 250 mV to around 700 mV, then maintains at around 700 mV. Through the 15 d bioleaching, the removal efficiencies of Cu, Zn, Pb and Cd are 52.1%, 65.8 %, 42.5 %, 83.25 %, respectively. Nevertheless, the maximal removal efficiencies of these metals with the combination of 2 d bioleaching and 3 h Fenton-like reaction reach to Cu-59.8 %, Zn-70.0 %, Pb-52.7 % and Cd-85.3 % respectively. The experience demonstrates that this method can dramatically enhance the removal efficiency of heavy metal, and greatly reduce the reaction time, which provides a relatively effective way to remove heavy metal from sediment.

关 键 词：重金属污染 底泥 生物淋滤 类芬顿反应 ACIDITHIOBACILLUS ferrooxidans 

分 类 号：X522[环境科学与工程—环境工程] TF18[冶金工程—冶金物理化学]