University of Central Florida, 4000 Central Florida Blvd., Orlando, FL 32816, United States.
J Hazard Mater. 2011 Sep 15;192(3):1380-7. doi: 10.1016/j.jhazmat.2011.06.052. Epub 2011 Jul 7.
The kinetic rate of dechlorination of a polychlorinated biphenyl (PCB-151) by mechanically alloyed Mg/Pd was studied for optimization of the bimetallic system. Bimetal production was first carried out in a small-scale environment using a SPEX 8000M high-energy ball mill with 4-μm-magnesium and palladium impregnated on graphite, with optimized parameters including milling time and Pd-loading. A 5.57-g sample of bimetal containing 0.1257% Pd and ball milled for 3 min resulted in a degradation rate of 0.00176 min(-1)g(-1) catalyst as the most reactive bimetal. The process was then scaled-up, using a Red Devil 5400 Twin-Arm Paint Shaker, fitted with custom plates to hold milling canisters. Optimization parameters tested included milling time, number of ball bearings used, Pd-loading, and total bimetal mass milled. An 85-g sample of bimetal containing 0.1059% Pd and ball-milled for 23 min with 16 ball bearings yielded the most reactive bimetal with a degradation rate of 0.00122 min(-1)g(-1) catalyst. Further testing showed adsorption did not hinder extraction efficiency and that dechlorination products were only seen when using the bimetallic system, as opposed to any of its single components. The bimetallic system was also tested for its ability to degrade a second PCB congener, PCB-45, and a PCB mixture (Arochlor 1254); both contaminants were seen to degrade successfully.
机械合金化 Mg/Pd 脱除多氯联苯（PCB-151）的动力学速率研究了双金属体系的优化。首先在 SPEX 8000M 高能球磨机中使用 4-μm-镁和浸渍在石墨上的钯进行小规模环境下的双金属生产，优化参数包括球磨时间和 Pd 负载量。含有 0.1257%Pd 的 5.57g 双金属样品，球磨 3 分钟，催化剂的降解速率为 0.00176 min(-1)g(-1)，是最具反应性的双金属。然后，使用 Red Devil 5400 Twin-Arm Paint Shaker 进行放大，该设备配备了定制的盘子来固定球磨罐。测试的优化参数包括球磨时间、使用的球轴承数量、Pd 负载量和总双金属质量。含有 0.1059%Pd 的 85g 双金属样品，球磨 23 分钟，使用 16 个球轴承，得到最具反应性的双金属，催化剂的降解速率为 0.00122 min(-1)g(-1)。进一步的测试表明，吸附不会阻碍萃取效率，并且只有在使用双金属体系时才会看到脱氯产物，而不是其任何单一成分。还测试了双金属体系对第二种 PCB 同系物 PCB-45 和 PCB 混合物（Arochlor 1254）的降解能力；这两种污染物都被成功降解。
