Preparation, characterization and adsorption potential of the NH4Cl-induced activated carbon for the removal of amoxicillin antibiotic from water

The preparation, characterization and application of NH4Cl-induced activated carbon (NAC) for amoxicillin removal from the contaminated water were studied. The prepared NAC had a specific surface area of 1029 m2/g and a mean pore volume of 2.46 nm. Over 99% of 50 mg/L amoxicillin (AMX) was adsorbed using 0.4 g NAC/L at the optimum solution pH of 6; while standard activated carbon (SAC) could only adsorb around 55% of AMX under similar experimental conditions. Kinetic analysis revealed that adsorption experimental data for both NAC and NAC were best fitted by the pseudo-second-order model, with the greater rate for NAC than for SAC. Results of equilibrium experiments indicated that adsorption of AMX onto SAC and NAC were better described by the Langmuir model. The maximum adsorption capacity of AMX onto SAC and NAC was 262 and 437 mg/g, respectively. AMX adsorption onto SAC increased from 76.8% to 92% with increased temperature from 10 to 35 °C. However, a further increase of temperature to 50 °C led to declining AMX removal to 78.1%. Overall, these results indicate that developed NAC was an efficient adsorbent that presents an attractive adsorbent method for application in treating contaminants in water.