Assessment of heavy metals mobility and correlative recovery and decontamination from MSWI fly ash: Mechanism and hydrometallurgical process evaluation
| Autor: | Shi Qingpu, Tangfu Xiao, Nana Wang, Hongguo Zhang, Diyun Chen, Hairong Peng, Lei Huang, Enzong Xiao, Minhua Su, Jinfeng Tang |
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| Rok vydání: | 2020 |
| Předmět: |
Cadmium
Environmental Engineering 010504 meteorology & atmospheric sciences Extraction (chemistry) chemistry.chemical_element Langmuir adsorption model Human decontamination 010501 environmental sciences 01 natural sciences Pollution symbols.namesake Adsorption chemistry Fly ash Environmental chemistry symbols Environmental Chemistry Leachate Leaching (metallurgy) Waste Management and Disposal 0105 earth and related environmental sciences |
| Zdroj: | The Science of the total environment. 768 |
| ISSN: | 1879-1026 |
| Popis: | Fly ash from municipal solid waste incineration (MSWI) enriches many leachable toxic metals which readily migrate into the environment, posing serious risks to the ecosystem and human. In this study, the elements mobility, leaching availability as well as the potential maximum amounts of heavy metals in fly ash were thoroughly evaluated. To decontaminate the toxic elements from resulting fly ash leachates, The aqueous zinc (Zn) was recovered using Cyanex 572, cadmium (Cd) and copper (Cu) were effectively removed through adsorption process by a self-assembled hierarchical hydroxyapatite (HAP) nanostructure. The removal mechanism of Cd, Cu and Zn by leaching, extraction and adsorption was revealed with the results from XRD, ICP-MS and SEM. The results showed that fly ash has a high mobility under maximum availability leaching test (95% of fly ash was dissolved), a recovery rate of 91% for Zn can be obtained using Cyanex 572, and a high adsorption rate (> 95% for both Cu and Cd) was reached using HAP for the pristine fly ash leachate. The outcomes from isothermal and kinetic study revealed that Langmuir isotherm and pseudo-second order model can well describe the Cd and Cu adsorption behavior. Economic assessment suggested that the application of HAP for the removal of Cd and Cu is a technically sound and economically feasible approach. The findings of this study demonstrated that this comprehensive process integrated leaching, solvent extraction and consequential decontamination can be a practical strategy for MSWI fly ash treatment. |
| Databáze: | OpenAIRE |
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