Characteristics of incineration ash for sustainable treatment and reutilization

• Published in: Environmental science and pollution research international 2019-06, Vol.26 (17), p.16974-16997
• Main Authors: Phua, Zhenghui, Giannis, Apostolos, Dong, Zhi-Li, Lisak, Grzegorz, Ng, Wun Jern
• Format: Article
• Language: English
• Subjects: Air pollution; Air Pollution - prevention & control; Air pollution control; Aluminum oxide; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Carbonation; Cement constituents; Chemical treatment; Coal Ash - chemistry; Combustion; Earth and Environmental Science; Ecotoxicology; Electrochemical Techniques - methods; Electrochemistry; Environment; Environmental Chemistry; Environmental Health; Environmental science; Fly ash; Heavy metals; Incineration; Incineration - methods; Inductively coupled plasma mass spectrometry; Leaching; Mass spectroscopy; Metal concentrations; Metals, Heavy - analysis; Municipal solid waste; Municipal waste management; Organic chemistry; Pollution control; Refuse Disposal - methods; Residues; Review Article; Salts; Separation; Separation processes; Silicon dioxide; Solid Waste - analysis; Solid waste management; Solidification; Stabilization; Vitrification; Waste disposal; Waste Water Technology; Water Management; Water Pollution Control; X-ray diffraction; X-ray fluorescence
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-019-05217-8

Municipal solid waste incineration (MSWI) generates bottom ash, fly ash (FA), and air pollution control (APC) residues as by-products. FA and APC residues are considered hazardous due to the presence of soluble salts and a high concentration of heavy metals, and they should be appropriately treated before disposal. Physicochemical characterization using inductively coupled plasma mass spectroscopy (ICP-MS), X-ray diffraction (XRD), and X-ray fluorescence (XRF) have shown that FA and APC have potential for reuse after treatment as these contain CaO, SiO 2 , and Al 2 O 3 . Studies conducted on treatment of FA and APC are categorized into three groups: (i) separation processes, (ii) solidification/stabilization (S/S) processes, and (iii) thermal processes. Separation processes such as washing, leaching, and electrochemical treatment improve the quality and homogeneity of the ash. S/S processes such as chemical stabilization, accelerate carbonation, and cement solidification modify hazardous species into less toxic constituents. Thermal processes such as sintering, vitrification, and melting are effective at reducing volume and producing a more stable product. In this review paper, the treatment processes are analyzed in relation to ash characteristics. Issues concerning mixing FA and APC residues before treatment, true treatment costs, and challenges are also discussed to provide further insights on the implications and possibilities of utilizing FA and APC as secondary materials.