Enhancing fluoride removal from wastewater using Al/Y amended sludge biochar

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Fluoride contamination in wastewater poses significant environmental and health risks.
• Conventional methods for fluoride removal often face limitations in efficiency and cost-effectiveness.
• Developing novel adsorbent materials is crucial for effective wastewater treatment.

Purpose of the Study:

• To investigate the efficacy of aluminum and yttrium amended sewage sludge biochar (Al/Y-CSBC) for fluoride removal from wastewater.
• To elucidate the adsorption mechanisms and kinetics of fluoride onto Al/Y-CSBC.
• To evaluate the reusability and performance of Al/Y-CSBC under various conditions.

Main Methods:

• Synthesis of aluminum and yttrium amended sewage sludge biochar (Al/Y-CSBC).
• Adsorption experiments to determine fluoride removal efficiency, kinetics, and isotherms.
• Characterization of the biochar material, including specific surface area and isoelectric point (pHpzc).
• Investigation of adsorption mechanisms through analysis of interactions.

Main Results:

• Al/Y-CSBC exhibited pseudo-second-order kinetics and Freundlich isotherm behavior for fluoride adsorption.
• Maximum adsorption capacity reached 62.44 mg·g⁻¹, with high efficiency across a wide pH range.
• The material demonstrated excellent reusability, retaining 95% removal efficiency after six cycles.
• Enhanced specific surface area and a high isoelectric point (pHpzc = 9.14) contributed to performance.

Conclusions:

• Al/Y-CSBC is a highly effective and reusable adsorbent for fluoride removal from wastewater.
• The enhanced adsorption capacity is attributed to the synergistic effects of aluminum and yttrium modification.
• This study presents a promising, novel approach for wastewater defluoridation using modified biochar.