Soil reconstruction using coal industry solid wastes: Linking pollution control with climate variability across...

Area of Science:

• Environmental Science
• Geotechnical Engineering
• Soil Science

Background:

• Coal industry solid wastes, including coal gangue, fly ash, and flue gas desulfurization gypsum, exceed 1.5 billion tons annually.
• These wastes cause land occupation and heavy-metal pollution, exacerbating soil degradation in mining areas.
• Conventional soil remediation techniques are often cost-prohibitive, necessitating alternative solutions.

Purpose of the Study:

• To review and synthesize research on utilizing coal industry solid wastes for soil reconstruction.
• To highlight the roles of different waste materials in improving soil properties.
• To identify challenges and propose a framework for effective application of this remediation strategy.

Main Methods:

• Literature review and synthesis of existing research on coal solid waste reuse in soil reconstruction.
• Analysis of material properties of coal gangue, fly ash, and FGD gypsum.
• Examination of structural evolution and ecological effects in reconstructed soils.

Main Results:

• Coal gangue provides structural support.
• Fly ash enhances soil pore structure and water retention.
• Flue gas desulfurization gypsum (FGD gypsum) supplies calcium ions (Ca2+) to promote soil aggregate formation.

Conclusions:

• Soil reconstruction using coal solid wastes is a viable strategy for remediation and mitigating contamination.
• Addressing challenges like leaching risks and scalability is crucial for successful on-site application.
• A framework connecting material properties, structural evolution, and ecological effects is essential for understanding waste reuse impacts.