Cadmium as the Critical Limiting Factor in the Co-Disposal of Municipal Solid Waste Incineration Fly Ash in Cement Kilns: Implications for Three-Stage Water Washing Efficiency and Safe Dosage Control
The co-disposal of municipal solid waste incineration fly ash (MSWI-FA) in cement kilns is an effective method for managing incineration by-products in China. However, the presence of heavy metals in MSWI-FA raises environmental concerns. This study analyzed the Cu, Zn, Cd, Pb, Cr, and Ni concentrat...
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2025-07-01
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| author | Zhonggen Li Qingfeng Wang Li Tang Liangliang Yang Guangyi Sun |
| author_facet | Zhonggen Li Qingfeng Wang Li Tang Liangliang Yang Guangyi Sun |
| author_sort | Zhonggen Li |
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| description | The co-disposal of municipal solid waste incineration fly ash (MSWI-FA) in cement kilns is an effective method for managing incineration by-products in China. However, the presence of heavy metals in MSWI-FA raises environmental concerns. This study analyzed the Cu, Zn, Cd, Pb, Cr, and Ni concentrations in MSWI-FA from 11 representative facilities across China and assessed the efficacy of a three-stage water washing process for Cl and heavy metal removal. The results revealed significant regional variations in heavy metal content that were strongly correlated with surface soil levels, with Zn, Pb, and Cu exhibiting the highest concentrations. Elemental correlations, such as Cu-Pb and Zn-Cd synergies and Cd-Ni antagonism, suggest common waste sources and temperature-dependent volatilization during incineration. The washing process (solid–liquid ratio = 1:10) achieved 97.1 ± 2.0% Cl removal, reducing residual Cl to 0.45 ± 0.32%, but demonstrated limited heavy metal elimination (10.28–19.38% efficiency), resulting in elevated concentrations (32.5–60.8% increase) due to 43.4 ± 9.2% mass loss. Notably, the washing effluents exceeded municipal wastewater discharge limits by up to 52-fold for Pb and 38-fold for Cd, underscoring the need for advanced effluent treatment. To mitigate environmental risks, the addition of washed MSWI-FA in cement kilns should be restricted to ≤0.5%, with Cd content prioritized in pre-disposal assessments. This study provides actionable insights for optimizing MSWI-FA co-processing while ensuring compliance with ecological safety standards. |
| format | Article |
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| institution | DOAJ |
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| language | English |
| publishDate | 2025-07-01 |
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| spelling | doaj-art-ebd7132ba9f648b49d2c8f7b1530e0ec2025-08-20T03:08:02ZengMDPI AGToxics2305-63042025-07-0113759310.3390/toxics13070593Cadmium as the Critical Limiting Factor in the Co-Disposal of Municipal Solid Waste Incineration Fly Ash in Cement Kilns: Implications for Three-Stage Water Washing Efficiency and Safe Dosage ControlZhonggen Li0Qingfeng Wang1Li Tang2Liangliang Yang3Guangyi Sun4School of Resources and Environment, Zunyi Normal College, Zunyi 563002, ChinaSchool of Resources and Environment, Zunyi Normal College, Zunyi 563002, ChinaGuizhou Research and Designing Institute of Environmental Sciences, Guiyang 550081, ChinaKey Laboratory of Karst Georesources and Environment, Guizhou University, Ministry of Education, Guiyang 550025, ChinaState Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, ChinaThe co-disposal of municipal solid waste incineration fly ash (MSWI-FA) in cement kilns is an effective method for managing incineration by-products in China. However, the presence of heavy metals in MSWI-FA raises environmental concerns. This study analyzed the Cu, Zn, Cd, Pb, Cr, and Ni concentrations in MSWI-FA from 11 representative facilities across China and assessed the efficacy of a three-stage water washing process for Cl and heavy metal removal. The results revealed significant regional variations in heavy metal content that were strongly correlated with surface soil levels, with Zn, Pb, and Cu exhibiting the highest concentrations. Elemental correlations, such as Cu-Pb and Zn-Cd synergies and Cd-Ni antagonism, suggest common waste sources and temperature-dependent volatilization during incineration. The washing process (solid–liquid ratio = 1:10) achieved 97.1 ± 2.0% Cl removal, reducing residual Cl to 0.45 ± 0.32%, but demonstrated limited heavy metal elimination (10.28–19.38% efficiency), resulting in elevated concentrations (32.5–60.8% increase) due to 43.4 ± 9.2% mass loss. Notably, the washing effluents exceeded municipal wastewater discharge limits by up to 52-fold for Pb and 38-fold for Cd, underscoring the need for advanced effluent treatment. To mitigate environmental risks, the addition of washed MSWI-FA in cement kilns should be restricted to ≤0.5%, with Cd content prioritized in pre-disposal assessments. This study provides actionable insights for optimizing MSWI-FA co-processing while ensuring compliance with ecological safety standards.https://www.mdpi.com/2305-6304/13/7/593municipal solid waste incineration fly ashheavy metalco-disposal with cement kilnsthree-stage water washingdosage estimation |
| spellingShingle | Zhonggen Li Qingfeng Wang Li Tang Liangliang Yang Guangyi Sun Cadmium as the Critical Limiting Factor in the Co-Disposal of Municipal Solid Waste Incineration Fly Ash in Cement Kilns: Implications for Three-Stage Water Washing Efficiency and Safe Dosage Control Toxics municipal solid waste incineration fly ash heavy metal co-disposal with cement kilns three-stage water washing dosage estimation |
| title | Cadmium as the Critical Limiting Factor in the Co-Disposal of Municipal Solid Waste Incineration Fly Ash in Cement Kilns: Implications for Three-Stage Water Washing Efficiency and Safe Dosage Control |
| title_full | Cadmium as the Critical Limiting Factor in the Co-Disposal of Municipal Solid Waste Incineration Fly Ash in Cement Kilns: Implications for Three-Stage Water Washing Efficiency and Safe Dosage Control |
| title_fullStr | Cadmium as the Critical Limiting Factor in the Co-Disposal of Municipal Solid Waste Incineration Fly Ash in Cement Kilns: Implications for Three-Stage Water Washing Efficiency and Safe Dosage Control |
| title_full_unstemmed | Cadmium as the Critical Limiting Factor in the Co-Disposal of Municipal Solid Waste Incineration Fly Ash in Cement Kilns: Implications for Three-Stage Water Washing Efficiency and Safe Dosage Control |
| title_short | Cadmium as the Critical Limiting Factor in the Co-Disposal of Municipal Solid Waste Incineration Fly Ash in Cement Kilns: Implications for Three-Stage Water Washing Efficiency and Safe Dosage Control |
| title_sort | cadmium as the critical limiting factor in the co disposal of municipal solid waste incineration fly ash in cement kilns implications for three stage water washing efficiency and safe dosage control |
| topic | municipal solid waste incineration fly ash heavy metal co-disposal with cement kilns three-stage water washing dosage estimation |
| url | https://www.mdpi.com/2305-6304/13/7/593 |
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