Simultaneous removal of antibiotic and nutrients via Prosopis juliflora activated carbon column: Performance evaluation, effect of operational parameters and breakthrough modeling

Abstract

In this study, the behavior of mono-component (metronidazole/phosphate/nitrate, MET/PO43−/NO3−) and multi-component (MET+PO43−+NO3−) adsorption in fixed-bed adsorption column was investigated using Prosopis juliflora activated carbon (PJAC). The influence of column operating parameters such as bed depth (H: 5–15 cm), influent flow rate (Q: 0.5–2 L/h) and adsorbate concentration (Co: 25–100 mg/L) on breakthrough curves were evaluated. The experimental data was correlated with breakthrough models viz. Thomas, Adams-Bohart, Yoon-Nelson and bed depth service time (BDST) models. The results showed that the Thomas model fitted the experimental data better than other models in predicting the breakthrough characteristics for the removal of MET, PO43− and NO3− by PJAC. The maximum adsorption capacity found by Thomas model was 9.70, 8.21 and 5.57 mg/g for MET, PO43− and NO3−, respectively. In multi-component systems, antagonistic behavior in sorption of MET, PO43− and NO3− was observed and as a result, adsorption capacity was 1.2–1.5 folds lesser than that observed in mono-component system. In conclusion, results of the present study indicate that the PJAC can be successfully employed for the removal of MET, PO43− and NO3− using fixed-bed adsorption column; however, the column design for multi-component mixture should be based on rapid breakthrough sorbate.