Li Zhonggen, Wang Qingfeng, Tang Li, Yang Liangliang, Sun Guangyi
School of Resources and Environment, Zunyi Normal College, Zunyi 563002, China.
Guizhou Research and Designing Institute of Environmental Sciences, Guiyang 550081, China.
Toxics. 2025 Jul 15;13(7):593. doi: 10.3390/toxics13070593.
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.
在中国，水泥窑协同处置城市生活垃圾焚烧飞灰（MSWI-FA）是管理焚烧副产物的有效方法。然而，MSWI-FA中重金属的存在引发了环境问题。本研究分析了中国11个代表性设施的MSWI-FA中铜、锌、镉、铅、铬和镍的浓度，并评估了三级水洗工艺去除氯和重金属的效果。结果显示，重金属含量存在显著的区域差异，且与表层土壤水平密切相关，其中锌、铅和铜的浓度最高。元素相关性，如铜-铅和锌-镉协同作用以及镉-镍拮抗作用，表明存在共同的废物来源以及焚烧过程中与温度相关的挥发。水洗工艺（固液比 = 1:10）实现了97.1±2.0%的氯去除率，将残留氯降低至0.45±0.32%，但重金属去除效果有限（去除效率为10.28 - 19.38%），由于质量损失43.4±9.2%，导致浓度升高（增加32.5 - 60.8%）。值得注意的是，水洗废水的铅含量超标高达52倍，镉含量超标高达38倍，这凸显了先进废水处理的必要性。为降低环境风险，水泥窑中添加水洗后的MSWI-FA应限制在≤0.5%，并在预处理评估中优先考虑镉含量。本研究为优化MSWI-FA协同处理提供了可行的见解，同时确保符合生态安全标准。
