Scholarlink

<p>The growing demand for energy, primarily produced through coal combustion in thermal power plants, leads to the generation of large quantities of fly ash containing potentially hazardous heavy metals. Inadequate disposal of this kind of waste can cause significant environmental harm. A proper handling of this waste material requires a comprehensive physicochemical characterization, and implementation of different analytical methods, in order to obtain as most complete insight into its qualitative and quantitative composition as possible. Standard digestion methods are associated with problems such as: (1) the use of HF, (2) digestion at high temperatures, and (3) long digestion time. Hence, in this work, a microwave-assisted acid digestion method using HNO<sub>3</sub>/H<sub>2</sub>SO<sub>4</sub>/H<sub>2</sub>O<sub>2</sub> with V<sub>2</sub>O<sub>5</sub> as a catalyst was developed and optimized and compared with the total digestion method (HF/HNO<sub>3</sub>/HCl). The influence of digestion temperature and time on the extraction efficiency of heavy metals from fly ash was evaluated. Higher temperatures improved the recovery of Cd, Co, Cr, Ni, Mn, Pb, and Zn (1.5 to 7 times), while lower temperatures favoured the extraction of volatile elements such as Hg (1 to 1.7 times) and As (5 to 15 times). The developed method detected higher concentrations of As (1 to 4 times) and Hg (10 to 80 times) compared to the HF/HNO<sub>3</sub>/HCl method during the digestion process at 200&#xa0;°C. Principal component analysis (PCA) grouped elements based on their behaviour during digestion, while hierarchical cluster analysis (HCA) revealed groupings based on digestion conditions. The study also included ecological and health risk assessments. All samples were categorized as having very high ecological risk, primarily due to elevated levels of Hg, Cd, and As. Health risk analysis identified Hg, Cr, Cd, and As, as the elements of highest concern. These findings emphasize the importance of optimized digestion protocols for accurate risk assessment and support the need for improved fly ash management strategies in the context of environmental protection.</p> Graphical abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Heavy metals in fly ash: chemometric modelling of extraction parameters and environmental and health risk assessment

  • 期刊论文

  • 发表日期：

    2025年12月1日

查看全文
  • Dušan V. Trajković,
  • Andrija Z. Janković,
  • Nevenka N. Mijatović,
  • Aleksandra A. Perić Grujić,
  • Dragana Z. Živojinović

摘要

The growing demand for energy, primarily produced through coal combustion in thermal power plants, leads to the generation of large quantities of fly ash containing potentially hazardous heavy metals. Inadequate disposal of this kind of waste can cause significant environmental harm. A proper handling of this waste material requires a comprehensive physicochemical characterization, and implementation of different analytical methods, in order to obtain as most complete insight into its qualitative and quantitative composition as possible. Standard digestion methods are associated with problems such as: (1) the use of HF, (2) digestion at high temperatures, and (3) long digestion time. Hence, in this work, a microwave-assisted acid digestion method using HNO3/H2SO4/H2O2 with V2O5 as a catalyst was developed and optimized and compared with the total digestion method (HF/HNO3/HCl). The influence of digestion temperature and time on the extraction efficiency of heavy metals from fly ash was evaluated. Higher temperatures improved the recovery of Cd, Co, Cr, Ni, Mn, Pb, and Zn (1.5 to 7 times), while lower temperatures favoured the extraction of volatile elements such as Hg (1 to 1.7 times) and As (5 to 15 times). The developed method detected higher concentrations of As (1 to 4 times) and Hg (10 to 80 times) compared to the HF/HNO3/HCl method during the digestion process at 200 °C. Principal component analysis (PCA) grouped elements based on their behaviour during digestion, while hierarchical cluster analysis (HCA) revealed groupings based on digestion conditions. The study also included ecological and health risk assessments. All samples were categorized as having very high ecological risk, primarily due to elevated levels of Hg, Cd, and As. Health risk analysis identified Hg, Cr, Cd, and As, as the elements of highest concern. These findings emphasize the importance of optimized digestion protocols for accurate risk assessment and support the need for improved fly ash management strategies in the context of environmental protection.

Graphical abstract