Faculty of Mechanical Engineering, Opole University of Technology, Mikołajczyka Str. 5, 45-271, Opole, Poland.
Sci Rep. 2023 Jan 30;13(1):1651. doi: 10.1038/s41598-023-28926-0.
One of the parameters affecting the leachability of heavy metals from waste is their contact time with the leachant. In this paper, the leaching behaviour of Zn, Cu, Pb and Ni was evaluated in relation to the liquid to solid ratio (L/S), which is a reflection of time after which a certain volume of water permeates the material, e.g. in slag heaps or landfills. A leaching study was carried out by different leaching methods with using three test materials, i.e. hazardous zinc slag, lump copper slag and mineral-organic composite. It was found that the highest amount of metals leached in the long term in the maximum availability test, under the following leaching conditions: L/S = 50 dm/kg, reduced pH of the leachant, fragmentation of the materials to particle size < 0.125 mm. Comparing the results obtained in the batch test and the percolation test, no strict trend was observed in the release of a given metal from different test materials. The analysis using the tank test showed that processes controlling leachability can result in the release of the highest metal loads immediately after contact between the material and the leachant, but can also contribute to the release of metals only after prolonged contact.
影响废物中重金属浸出率的参数之一是它们与浸出剂的接触时间。本文研究了液固比（L/S）对 Zn、Cu、Pb 和 Ni 浸出行为的影响，L/S 反映了一定体积的水渗透到材料中的时间，例如在渣堆或垃圾填埋场中。采用三种试验材料，即危险锌渣、块状铜渣和矿物-有机复合材料，通过不同的浸出方法进行了浸出研究。结果发现，在最大可用浸出试验中，在以下浸出条件下，长期浸出的金属量最大：L/S=50dm/kg，浸出剂 pH 值降低，材料破碎至粒径<0.125mm。比较批式试验和渗滤试验的结果，从不同试验材料中释放出给定金属时，没有观察到严格的趋势。槽式试验分析表明，控制浸出率的过程可能导致在材料与浸出剂接触后立即释放出最高的金属负荷，但也可能导致在长时间接触后才释放出金属。
