文献类型：期刊文献

英文题名：Risk assessment of lead and cadmium leaching from solidified/stabilized MSWI fly ash under long-term landfill simulation test

作者：Wang, Yitian[1];Hu, Yang[1];Xue, Cheng[1];Khan, Asim[1];Zheng, Xinyu[1];Cai, Lankun[1]

机构：[1]East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China

年份：2022

卷号：816

外文期刊名：SCIENCE OF THE TOTAL ENVIRONMENT

收录：;EI(收录号：20214611148886);WOS:【SCI-EXPANDED(收录号:WOS:000766809600011)】；

基金：This study was financially supported by the enterprise grant [B200-81639] from Donghua Environmental Protection Technology Co., Ltd. (Changzhou, China) . In addition, the authors thank Research Center of Analysis and Test of East China University of Science and Technology for the help on the SEM, XRD and ICP-OES analysis.

语种：英文

外文关键词：Municipal solid waste incineration fly ash; Long-term stability; Risk assessment; Heavy metals; Decalcification

摘要：The long-term effectiveness concern of municipal solid waste incineration (MSWI) fly ash (FA) disposal has been placed more emphatic recently, however, few studies worked on the control of leaching risk of heavy metals under the long-term stability. In this study, the leaching properties and risk assessment of two representative solidified/stabilized (S/S) FA wastes, i.e., sodium dithiocarbamate (DTC) chelator treated and Portland cement + chelator combining treated, were evaluated by a long-term cycles assessment method which coupled multifaceted environmental stresses (e.g., freezing-thawing, drying-wetting, accelerated carbonation). The results showed that the cement/chelator had a better long-term stability and exhibited-55% lower cumulative overall pollution toxicity index (OPTI) than chelator treatment after the test, which was always rated as "low risk" during the cycles. In addition, the cement/chelator exhibited-23.3% smaller cumulative mass release rate than the chelator treatment after 6 cycles and restrained the transformation of Pb and Cd from stable states to removable fractions, which attributes to its great erosion resistance and compact pore structure. Under the cumulative external factors and carbon dioxide attacks, the decalcification of hydrate products (e.g., C-S-H, hydrocalumite), as well as deterioration of pore structure are the critical factors increasing the local erosion, cracking and heavy metals release. Thus, the optimization of S/S waste microstructure (e.g., enhancing binder system) and landfill site conditions (e.g., reducing rainfall impact) could be propitious to the S/S waste risk control and management. (c) 2021 Elsevier B.V. All rights reserved.