Batch and column study on tetracycline removal using green synthesized NiFe nanoparticles immobilized alginate beads

Abstract

Abstract In the current work, NiFe nanocomposite was synthesized using polyphenol rich pomegranate (Punica granatum) peel extract and NiFe was immobilized into biocompatible and biodegradable alginate to form NiFe nanocomposite beads (GS-NiFe beads). This study is a best ecofriendly approach for the effective removal of tetracycline (TC) from aqueous solutions. The factors influencing the removal were optimized using response surface methodology (RSM-CCD). Applying the optimized conditions (20 mg/L of TC initial concentration; 1000 mg/L GS-NiFe concentration in beads; bead weight (wet): 20 % (W/V); interaction time 90 min), 99% removal was obtained in batch reactor. The removal process followed pseudo second order kinetics. Both adsorption and degradation played crucial role in the remediation process. The continuous flow study in the column reactors was performed varying the flow rate, initial TC concentration, and bed height. The maximum removal capacity (487 ± 6.84 mg/g) was achieved under the reaction conditions: bed height: 15 cm; initial TC concentration: 20 mg/L; and flow rate: 1 mL/min. Under optimized conditions, the applicability of GS-NiFe beads was further confirmed using TC spiked natural water samples in column reactors. The cell viability assessment of the treated solution was performed towards environmentally relevant bacteria and algae, which indicated a considerable decline in the toxic effects.