EFEKTIVITAS EFEKTIVITAS ADSORPSI LIMBAH ANTIBIOTIK ENROFLOXACIN MENGGUNAKAN HYDROCHAR KULIT KAPUK (CEIBA PENTANDRA) TERAKTIVASI KOH

Abstract

Water pollution caused by antibiotic residues—particularly enrofloxacin—is an escalating environmental concern due to their persistence and potential to foster microbial resistance. A promising approach to addressing this issue is the use of adsorption with biomass-based adsorbents. This study aimed to evaluate the effectiveness of KOH-activated hydrochar derived from kapok (Ceiba pentandra) husks as an adsorbent for removing enrofloxacin from solution. It also sought to determine optimal adsorption conditions by examining variables such as particle size, adsorbent dosage, initial enrofloxacin concentration, pH, contact time, and water type. The hydrochar was produced via a hydrothermal process at 200°C for 10 hours and subsequently chemically activated using a 1 M KOH solution. Functional groups were characterized using Fourier Transform Infrared Spectroscopy (FTIR), while enrofloxacin levels were analyzed via UV-Vis spectrophotometry at a wavelength of 324 nm. The results demonstrated that 120-mesh hydrochar exhibited superior adsorption performance compared to 140-mesh and 160-mesh variants, offering an optimal balance of surface area, pore accessibility, and structural stability. Peak adsorption efficiency—approximately 73%—was achieved at pH 7 with an adsorbent dosage of 0.5 g/L, an initial enrofloxacin concentration of 5 mg/L, and a contact time of 60 minutes. Distilled water yielded the highest adsorption efficiency compared to rainwater and river water. FTIR analysis revealed the presence of O–H, aromatic C=C, and C–O functional groups, which facilitate the adsorption process through hydrogen bonding, electrostatic interactions, and π–π interactions. Overall, the study indicates that KOH-activated kapok husk hydrochar holds potential as an eco-friendly, cost-effective, and sustainable adsorbent for treating wastewater containing antibiotic residues.