Comparative Study of the Removal Efficiency of Nalidixic Acid by Poly[(4-vinylbenzyl)trimethylammonium Chloride] and N-Alkylated Chitosan through the Ultrafiltration Technique and Its Approximation through Theoretical Calculations

Abstract

Emerging antibiotic contaminants in water is a global problem because bacterial strains resistant to these antibiotics arise, risking human health. This study describes the use of poly[(4-vinylbenzyl) trimethylammonium chloride] and N-alkylated chitosan, two cationic polymers with different natures and structures to remove nalidixic acid. Both contain ammonium salt as a functional group. One of them is a synthetic polymer, and the other is a modified artificial polymer. The removal of the antibiotic was investigated under various experimental conditions (pH, ionic strength, and antibiotic concentration) using the technique of liquid-phase polymer-based retention (LPR). In addition, a stochastic algorithm provided by Fukui’s functions is used. It was shown that alkylated N-chitosan presents 65.0% removal at pH 7, while poly[(4-vinylbenzyl)trimethylammonium chloride] removes 75.0% at pH 9. The interaction mechanisms that predominate the removal processes are electrostatic interactions, π–π interactions, and hydrogen bonding. The polymers reached maximum retention capacities of 1605 mg g−1 for poly[(4-vinylbenzyl) trimethylammonium chloride] and 561 mg g−1 of antibiotic per gram for alkylated poly(N-chitosan). In conclusion, the presence of aromatic groups improves the capacity and polymer–antibiotic interactions.

Biopolymeric Nanocomposites for Wastewater Remediation: An Overview on Recent Progress and Challenges

“…Palacio et al tackled the global challenge of antibiotic contaminants in water, focusing on nalidixic acid removal using two cationic polymers: poly[(4-vinylbenzyl) trimethylammonium chloride] and N-alkylated chitosan. The removal processes are governed by electrostatic interactions, π–π interactions, and hydrogen bonding, as revealed by their effectiveness under varying conditions, with distinct removal rates—75.0% at pH 9 for poly[(4-vinylbenzyl) trimethylammonium chloride] and 65.0% at pH 7 for alkylated N-chitosan [ 151 ]. Valizadeh et al innovatively tackled tetracycline (TC) antibiotic pollution by introducing a zinc ferrite/chitosan–curdlan magnetic composite.…”