Optimization of custard apple (Annona squamosa L.) seed biochar for PFOA adsorption: effects of acid, base, and metal salt modification

Key Points

• Enhanced adsorption of perfluorooctanoic acid (PFOA) observed with modified biochar.
• Biochar underwent acid, base, and metal salt modifications to improve performance.
• This study employed a systematic approach to evaluate different modification effects on adsorption rates.
• The findings may enable more effective strategies for environmental remediation using biochar.