School of Water, Energy and Environment, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK.
Digital Laboratories, British Geological Survey, Nottingham NG12 5GG, UK.
Waste Manag. 2023 Mar 1;158:116-124. doi: 10.1016/j.wasman.2023.01.011. Epub 2023 Jan 17.
The recovery of 12 critical raw materials (CRM) from municipal solid wastes (MSW) via leachate recirculation was evaluated using a 4 L semi-pilot scale column percolation. The results showed that the recovery of the metal(loid)s was mainly influenced by order of importance: pH > organic content > type of metal(loid)s > age of the waste > redox potential. Among the CRM, Cd and Ni were the most mobile elements, while As and Cr were the least mobile. A comparison of leachate from the leachate recirculated columns before and after the initiation of recirculation indicates an increase in the concentrations of certain CRM and metalloids. The first recirculation cycle supported achieving 100 % recovery. CRM and metalloids in leachate can be recovered; however, the concentrations of CRM and metalloids are usually below 1 mg/L. In this regard, leachate recirculation may enhance the increasing concentration of CRM in landfill leachate. For example, after first recirculation cycle, Ni concentration increased from 0.05 mg/L to 0.11 mg/L. The results obtained from this study can develop further methodologies for the potential recovery of CRM and help foster further research into overcoming limitations for recovering CRM in landfill leachate.
采用 4 L 半连续柱渗滤实验，评估了通过渗滤液循环从城市固体废物 (MSW) 中回收 12 种关键原材料 (CRM) 的效果。结果表明，金属（类）的回收主要受以下因素影响，重要性依次为：pH 值>有机含量>金属（类）的类型>废物的年龄>氧化还原电位。在 CRM 中，Cd 和 Ni 是最具迁移性的元素，而 As 和 Cr 则是最不具迁移性的元素。在开始循环之前和之后，对渗滤液循环柱中的渗滤液进行了比较，表明某些 CRM 和类金属的浓度有所增加。第一个循环就支持实现了 100%的回收率。可以从渗滤液中回收 CRM 和类金属，但 CRM 和类金属的浓度通常低于 1mg/L。在这方面，渗滤液循环可能会增强垃圾渗滤液中 CRM 浓度的增加。例如，在第一个循环之后，Ni 的浓度从 0.05mg/L 增加到 0.11mg/L。本研究的结果可以为 CRM 的潜在回收开发进一步的方法，并有助于进一步研究克服从垃圾渗滤液中回收 CRM 的限制。
