Department of Environmental Science and Engineering, Sichuan University, Chengdu, 610065, China.
Environ Sci Pollut Res Int. 2022 Sep;29(42):63393-63406. doi: 10.1007/s11356-022-20280-4. Epub 2022 Apr 22.
With the extensive use of nonferrous metals and metal catalysts, solid wastes containing heavy metals release metal ions into soil and surface water through erosion and leaching. This is one of the major threats to the global environment and human health. Studying the characteristics and impact factors of heavy metal leaching from solid waste is a critical part of managing spent catalysts and environmental risk. In this work, the characteristics of and factors that influence leaching and seepage release from typical spent catalysts and lead-zinc smelting slag were studied. The results indicated that metal ions leached more easily in an acidic environment (pH 4.5) and an environment with DOM than in a neutral environment (pH 7.0). Metal ion leaching was favored by a liquid-to-solid ratio of 20:1. The concentrations of metal ions released from the spent catalysts in sequential leaching experiments were higher than those in column leaching experiments. Leaching of metal ions in the presence of different leaching agents and from different spent catalysts can be described by different controlling models of the shrinking core model, but changes in the liquid-to-solid ratio showed no obvious correlation with changes in the metal release mechanism. These results provide important information for spent catalyst management and risk prevention and control.
随着有色金属和金属催化剂的广泛使用，含有重金属的固体废物通过侵蚀和浸出将金属离子释放到土壤和地表水。这是对全球环境和人类健康的主要威胁之一。研究固体废物中重金属浸出的特性和影响因素是管理废催化剂和环境风险的关键部分。在这项工作中，研究了典型废催化剂和铅锌冶炼渣浸出和渗滤释放的特性和影响因素。结果表明，金属离子在酸性环境（pH4.5）和含有 DOM 的环境中比在中性环境（pH7.0）中更容易浸出。液固比为 20:1 时有利于金属离子浸出。顺序浸出实验中从废催化剂释放的金属离子浓度高于柱浸出实验。不同浸出剂和不同废催化剂中金属离子的浸出可以用收缩核模型的不同控制模型来描述，但液固比的变化与金属释放机制的变化没有明显的相关性。这些结果为废催化剂管理和风险预防控制提供了重要信息。
