Antagonistic and synergistic analysis of antibiotic adsorption on Prosopis juliflora activated carbon in multicomponent systems

The synergistic and antagonistic adsorption involved in the removal of antibiotics in multicomponent systems was investigated. In this study, potassium hydroxide (KOH) activated Prosopis juliflora activated carbon (KPAC) was prepared, characterized and used for the removal of sulfadiazine (SDZ), metronidazole (MET) and tetracycline (TET) antibiotics from single, binary and ternary adsorption systems. The effects of experimental parameters i.e. contact time, adsorbent dose, pH and initial adsorbate concentration was investigated. Traditional kinetic and isotherm models were utilized to model experimental kinetic and equilibrium data. Meanwhile, Langmuir's competitive model was used to investigate adsorption capacity in multicomponent systems. Subsequently, kinetics and equilibrium data were better represented by pseudo-second-order and Langmuir isotherm models, respectively. The results showed that maximum sorption capacity of KPAC was 18.48, 25.06 and 28.81 mg/g for removal of SDZ, MET and TET, respectively, in single-component adsorption system. Moreover, total adsorption yield of single-component system was higher in comparison with multicomponent adsorption systems. Furthermore, the results showed that multicomponent systems exhibited both antagonistic and synergistic adsorption of antibiotics. Desorption study showed that maximum desorption of SDZ, MET and TET was 11.7%, 22.5% and 13.9%, respectively. In conclusion, KPAC has potential to be used as an adsorbent for removal of antibiotic(s).