School of Mathematics and Information, Guangzhou University, Guangzhou, 510006, China.
Guangdong Provincial Engineering Technology Research Center for Wastewater Management and Treatment, School of Environment, South China Normal University, Guangzhou, 510006, China.
Sci Rep. 2021 Jan 28;11(1):2499. doi: 10.1038/s41598-021-81812-5.
Co-combustion of municipal excess sludge (ES) and coal provides an alternative method for disposing ES. The present study aims to investigate the residual and ecological risk of heavy metals in fly ash from co-combustion of ES and coal. The total concentration and speciation distribution of heavy metals, characterization of SEM, EDX, XRD and leaching test were carried out to assess the fly ash in this study. The results showed that the total concentrations of Cu, Zn and Mn were higher than others in fly ash, and most heavy metals were concentrated in fine particles. For Cd, Cr and Pb, the percentages of speciation of F4 and F5 were all over 90%, suggesting the relatively lower leaching toxicity. The leaching percent of all heavy metals was lower than 5% by two diluted HNO solutions for fly ash. The potential ecological risks increased with the decrease of particle size of fly ash, and Cd accounted for the main fraction for ecological risk despite of lower concentration in comparison to other measured heavy metals.
城市剩余污泥（ES）与煤共燃烧为处理 ES 提供了一种替代方法。本研究旨在研究 ES 与煤共燃烧飞灰中重金属的残留和生态风险。通过总浓度和重金属形态分布、SEM、EDX、XRD 特征及浸出试验对飞灰进行了评估。结果表明，飞灰中 Cu、Zn 和 Mn 的总浓度高于其他重金属，且大多数重金属集中在细颗粒中。对于 Cd、Cr 和 Pb，F4 和 F5 形态的比例均超过 90%，表明浸出毒性相对较低。两种稀释 HNO3 溶液对飞灰中所有重金属的浸出率均低于 5%。潜在生态风险随着飞灰粒径的减小而增加，尽管 Cd 的浓度低于其他测量的重金属，但 Cd 占生态风险的主要部分。
