School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore; Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, 1 Cleantech Loop, 637141, Singapore.
Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, 1 Cleantech Loop, 637141, Singapore.
Waste Manag. 2024 Apr 15;178:339-350. doi: 10.1016/j.wasman.2024.02.045. Epub 2024 Mar 1.
Leaching of potentially hazardous substances, especially the heavy metals from Incineration Bottom Ash (IBA) is a major problem in its recyclable usage. To address this concern, treatment of IBA is indispensable before it can be reused. IBA subjected to laboratory-scale treatment typically yields clearer conclusions in terms of leaching behaviors, benefiting from the controlled laboratory environment. However, the leaching behaviors of commercially treated IBA appear to be more ambiguous due to the complex and comprehensive nature of industrial-scale treatments, where multiple treatment techniques are involved concurrently. Furthermore, treatment efficiencies vary among different plants. In this study, three types of commercially treated IBA were sampled from leading waste treatment companies in Singapore. Characterization and leaching tests were performed on the treated IBAs in both standardized and modified manners to simulate various scenarios. Besides deionized water, artificial seawater was used as a leachant in leaching tests for simulating seawater intrusion. The results reveal the promoting effect of seawater on the leaching levels of several elements from three types of treated IBA, which may require special attention for IBA application and landfill near the coast. Furthermore, the elements examined in these three types of commercially treated IBA generally comply with the non-hazardous waste acceptance criteria outlined in Council Decision, 2003/33/EC (2003), except Sb. By combining two leaching tests, the elements were categorized into different types of leaching behavior, making it possible to prepare and respond to the concerning leaching scenarios in future engineering applications.
焚烧底灰（IBA）中潜在危险物质，特别是重金属的浸出是其可回收利用的主要问题。为了解决这个问题，在重复使用之前，必须对 IBA 进行处理。在实验室规模下对 IBA 进行处理通常可以更清楚地了解浸出行为，这得益于受控的实验室环境。然而，由于工业规模处理的复杂性和综合性，涉及多种处理技术同时进行，商业处理的 IBA 的浸出行为似乎更加模糊。此外，不同工厂的处理效率也有所不同。在这项研究中，从新加坡领先的废物处理公司采集了三种商业处理的 IBA。对经过处理的 IBA 进行了标准化和改良的特性和浸出测试，以模拟各种情况。除去离子水外，人工海水也被用作浸出测试的浸出剂，以模拟海水入侵。结果表明，海水对三种类型的经过处理的 IBA 中几种元素的浸出水平有促进作用，这可能需要特别注意 IBA 在沿海地区的应用和垃圾填埋。此外，这三种商业处理的 IBA 中检查的元素通常符合理事会决定（2003/33/EC）（2003 年）中规定的非危险废物接受标准，除 Sb 外。通过结合两种浸出测试，可以将元素分为不同类型的浸出行为，这使得在未来的工程应用中可以准备和应对相关的浸出情况。
