Efficient removal of triazole fungicides from water using spent coffee grounds-derived hypercrosslinked polymers: A...

The widespread use of pesticides, which is critical to promote agricultural production, causes severe environmental pollution. Turning biomass waste into adsorbents for pesticide residue removal is a promising strategy that achieves pollutant removal and waste reuse. In this study, a biomass-derived hypercrosslinked polymer (SHCPs) was innovatively fabricated from the extract of spent coffee grounds (SCGs) as the precursor via the Friedel-Crafts alkylation reaction. Notably, this material is low-cost, eco-friendly and recyclable. Thanks to the high specific surface area of 1575 m²/g, abundant functional groups and excellent thermal stability of SHCPs, the maximum adsorption capacity for triazole fungicides reached 264.04 mg/g. Results from interference experiments involving ionic strength, pH and dissolved organic matter demonstrated the material's strong anti-interference performance. At the same time, SHCPs maintained an adsorption efficiency of over 90% after five cycles. Based on experimental characterizations and theoretical calculations, the adsorption mechanism may involve π-π stacking, hydrogen bonding, hydrophobic interaction, electrostatic interaction and pore-filling effect. We propose a sustainable approach to repurpose biomass waste into an adsorbent, advancing a circular economy solution for water treatment.