Magnetic carboxymethyl gond katira-grafted-poly(3-aminobenzoic acid) as an antibacterial biosorbent for purification of acetamiprid-contaminated water

Abstract

The elimination of pesticides from polluted water is critical due to their harmful environmental and biological impacts. Recently, there has been interest in utilizing natural polymer-based adsorbents as an eco-friendly approach to eliminate or reduce the levels of water pollutants. In this work, we synthesized an antimicrobial and magnetic bionanocomposite consisting of carboxymethyl gond katira-grafted- poly(3-aminobenzoic acid) with iron oxide and zinc oxide NPs (CMT-g-P3ABA/ZnO/Fe₃O₄) through an in situ polymerization reaction and examined for its ability to adsorb the pesticide acetamiprid (AP). The bionanocomposite was characterized using several analytical techniques, including spectroscopy; XRD presented the crystalline structure of ZnO/Fe₃O₄ in the CMT-g-P3ABA amorphous matrix. The ZnO/Fe₃O₄ partially aggregated formation and exhibited polyhedral crystal shapes was depicted by electron microscopy images, vibrating sample magnetometer (45.06 emu/g), porosimetry (5.52 m²/g), and thermal (Chair yield of approximately 43.83 %) and elemental analyses. Under various conditions, including solution pH (4-9), adsorbent dosage (0.005-0.025 g), time of contact (10-30 min), and pesticide preliminary concentration (200-400 mg/L) in 10 mL of the solution. Based on this research, Adsorption data were perfectly fitted by the Freundlich isotherm model with R_AP²= 0.99038, while the pseudo-second-order (PSO) model well-explained adsorption kinetics with R_AP²= 0.99847. AP adsorption to the CMT-g-P3ABA/ZnO/Fe₃O₄ bionanocomposite was successful due to hydrophobic interactions, hydrogen bonding, and π-π stacking. Furthermore, adsorption-desorption experiments demonstrated that the bionanocomposite could be regenerated after three reuse cycles without considerable loss of pesticide removal performance. The bionanocomposite also exhibited promising antimicrobial activity in contradiction to test bacteria.

Keywords: Acetamiprid; Adsorption; Antimicrobial; Bionanocomposite; Gond katira; Natural polymer.