Recent progress of biochar for aquatic pollutant control: Modification, mechanism and application

Area of Science:

• Environmental Science
• Materials Science
• Chemistry

Background:

• Water pollution is a critical global issue.
• Biochar offers a sustainable and cost-effective solution for water remediation.
• Recent advancements have significantly improved biochar's properties for pollutant adsorption.

Purpose of the Study:

• To review the latest engineering advances in biochar modification for water treatment.
• To propose a novel multi-pathway synergistic strategy for enhanced pollutant removal.
• To establish a design framework and mechanistic hierarchy for next-generation biochar reactors.

Main Methods:

• Analysis of physical/chemical activation, hetero-atom doping, template-assisted synthesis, and O-functionalization.
• Review of biochar's textural and chemical attribute enhancements.
• Investigation of integrated decontamination pathways including adsorption, oxidation, precipitation, and complexation.

Main Results:

• Engineered biochars exhibit high surface areas (1500-2600 m² g⁻¹) and heavy metal uptake capacities (200-450 mg g⁻¹).
• Modified biochars effectively remove pollutants like phosphate (>80%), heavy metals, dyes, antibiotics, and pesticides.
• The proposed strategy integrates multiple removal mechanisms for synergistic effects.

Conclusions:

• Next-generation biochar reactors should adopt a multi-pathway synergistic approach.
• A ternary design framework (pore-surface-electronic properties) is crucial for optimizing biochar performance.
• Understanding mechanistic coupling and environmental influences is key for effective water decontamination.