ADSORPTION OF CHLORAMPHENICOL BY SAGO BARK-BASED ACTIVATED CARBON OPTIMIZED BY RESPONSE SURFACE METHODOLOGY

Abstract

When discharge into the environment, antibiotics like chloramphenicol (CAP), can pose significant environmental hazards, including harm to aquatic ecosystems. This pressing issue motivated the current study, which focuses on the development of sago bark-based activated carbon (SBAC) for the effective removal of CAP from water. SBAC was synthesized through a combined physicochemical activation approach involving chemical activation with potassium hydroxide (KOH) and subsequent microwave-assisted physical activation using carbon dioxide (CO₂) gas. The synthesis process was optimized using response surface methodology (RSM) with a central composite design (CCD). The optimal conditions were identified as a radiation power of 343.56 W, an activation time of 17.13 minutes, and a KOH impregnation ratio (IR) of 1.62 g/g. Under these optimized parameters, the SBAC achieved a CAP adsorption capacity of 68.87 mg/g and a production yield of 32.81%. The predictive models demonstrated high reliability, with actual results closely matching the predicted values, evidenced by low error rates of 2.41% for CAP uptake and 1.45% for yield. Structural analysis using scanning electron microscopy (SEM) highlighted a stark transformation in the material’s morphology. The raw sago bark exhibited a dense, non-porous surface, whereas the activation process significantly enhanced its porosity, producing a highly porous SBAC surface. This confirmed the effectiveness of the combined activation techniques in creating a material with superior adsorption properties. The Brunauer-Emmett-Teller (BET) surface area of SBAC was 1003.23 m²/g. Isotherm studies revealed that the adsorption of CAP onto SBAC adhered to the Freundlich model, indicative of multilayer adsorption on a heterogeneous surface. The material demonstrated an impressive maximum adsorption capacity, Q_m of 131.83 mg/g, showcasing its potential as an efficient adsorbent for mitigating antibiotic contamination in water.