Ramos-Ruiz Adriana, Wilkening Jean V, Field James A, Sierra-Alvarez Reyes
Department of Chemical and Environmental Engineering, The University of Arizona, P. O. Box 210011, Tucson, AZ, 85721-0011, USA.
Department of Chemical and Environmental Engineering, The University of Arizona, P. O. Box 210011, Tucson, AZ, 85721-0011, USA.
J Hazard Mater. 2017 Aug 15;336:57-64. doi: 10.1016/j.jhazmat.2017.04.052. Epub 2017 Apr 24.
A crushed non-encapsulated CdTe thin-film solar cell was subjected to two standardized batch leaching tests (i.e., Toxicity Characteristic Leaching Procedure (TCLP) and California Waste Extraction Test (WET)) and to a continuous-flow column test to assess cadmium (Cd) and tellurium (Te) dissolution under conditions simulating the acidic- and the methanogenic phases of municipal solid waste landfills. Low levels of Cd and Te were solubilized in both batch leaching tests (<8.2% and <3.6% of added Cd and Te, respectively). On the other hand, over the course of 30days, 73% of the Cd and 21% of the Te were released to the synthetic leachate of a continuous-flow column simulating the acidic landfill phase. The dissolved Cd concentration was 3.24-fold higher than the TCLP limit (1mgL), and 650-fold higher than the maximum contaminant level established by the US-EPA for this metal in drinking water (0.005mgL). In contrast, the release of Cd and Te to the effluent of the continuous-flow column simulating the methanogenic phase of a landfill was negligible. The remarkable difference in the leaching behavior of CdTe in the columns is related to different aqueous pH and redox conditions promoted by the microbial communities in the columns, and is in agreement with thermodynamic predictions.
将一个破碎的非封装碲化镉（CdTe）薄膜太阳能电池进行了两项标准化批量浸出试验（即毒性特性浸出程序（TCLP）和加利福尼亚废物提取试验（WET））以及一项连续流柱试验，以评估在模拟城市固体垃圾填埋场酸性和产甲烷阶段的条件下镉（Cd）和碲（Te）的溶解情况。在两项批量浸出试验中，Cd和Te的溶解量都很低（分别占添加的Cd和Te的<8.2%和<3.6%）。另一方面，在30天的时间里，73%的Cd和21%的Te释放到了模拟酸性填埋阶段的连续流柱的合成渗滤液中。溶解的Cd浓度比TCLP限值（1mg/L）高3.24倍，比美国环境保护局（US-EPA）为饮用水中该金属设定的最大污染物水平（0.005mg/L）高650倍。相比之下，Cd和Te释放到模拟填埋场产甲烷阶段的连续流柱流出物中的量可以忽略不计。CdTe在柱中的浸出行为存在显著差异，这与柱中微生物群落促进的不同水相pH值和氧化还原条件有关，并且与热力学预测结果一致。
