Efficient removal of tebuconazole from wastewater by zinc‐modified passion fruit peels: Adsorption behaviour and mechanism

Abstract In this research, an effective adsorbent, ZnCl2‐modified biochar (Zn‐PFPB), was prepared from unprocessed passion fruit peel (PFP) for the removal of tebuconazole (TE) from wastewater. The synthesized Zn‐PFPB was characterized by Fourier transform infrared spectroscopy (FT‐IR), scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), N 2 adsorption/desorption curves, and point of zero charge, which suggested that Zn‐PFPB had an amorphous structure and high porosity. Optimal TE removal occurred at pH 2 with an adsorbent dosage of 0.5 g L −1 . The kinetics of the adsorption process followed the pseudo‐second‐order model while the isotherm model used was the Langmuir model, suggesting monolayer chemisorption. The maximum adsorption capacity reached 201.32 mg g −1 for TE. The adsorption mechanisms were pore filling, hydrogen bonding, π‐π interactions, and surface complexation. Importantly, Zn‐PFPB maintained removal efficiency of more than 65% over a broad pH range (2–10), which can be considered as a promising candidate for practical applications. The regeneration rate of Zn‐PFPB was determined to be 70% after the third cycle when using 1 mol L −1 NaOH. The cost analysis showed a fabrication cost of $5.093/kg for Zn‐PFPB. Batch mode scale‐up design showed that 18 g of Zn‐PFPB can remove 95% TE from 50 L of wastewater containing 50 mg L −1 TE. This work proposes a new, economical, and eco‐friendly way of managing agricultural waste in wastewater treatment and soil management.