Forest biomass derived biochar for effective meropenem mitigation in hospital effluents

Abstract

This study explores the use of forest biomass-derived biochar for the efficient removal of meropenem (MRP), a persistent antibiotic found in hospital wastewater. Raw commercial biochar was modified using different activation methods (alkali, ultrasound, and microwave), with NaOH-activated biochar (BCA2) showing superior performance. BCA2 achieved 100 % removal of MRP at 5 mg dm^-3, and 75 % removal at 50 mg dm^-3 after five adsorption-desorption cycles. Characterization revealed a highly porous structure with oxygenated functional groups enhancing adsorption. The process was efficient across a broad pH range (3–10), with removal rates ranging from 75 to 97 %, and demonstrated better performance than commercial granular activated carbon (GAC) in reuse scenarios. Adsorption followed pseudo-second-order kinetics and fitted well to the Langmuir model, with a maximum adsorption capacity of 17.2 mg g^-1. Thermodynamic analysis indicated a spontaneous and endothermic process. Application in simulated hospital effluents confirmed complete MRP removal and a decrease in overall salinity, demonstrating the material’s robustness under complex water matrices. These findings highlight the potential of low-cost, modified biochar as an eco-friendly and effective adsorbent for treating antibiotic-contaminated effluents in real-world conditions.