Ultrafiltration membranes with three water-soluble polyelectrolyte copolymers to remove ciprofloxacin from aqueous systems

Water pollution is a serious problem throughout the world, and antibiotics released into the aquatic environment produce harmful effects on the ecosystem and human health. In this investigation, the elimination of ciprofloxacin (CIP) by the retention technique based on polymers in liquid phase was evaluated using three soluble polyelectrolyte copolymers with different charge ratios: poly[3-(methacryloylamino) propyl] dimethyl (3-sulfopropyl) ammonium hydroxide-co-(4-(vinylbenzyl) trimethylammonium chloride]] (CP1), poly[3-(methacryloylamino) propyl]dimethyl (3-sulfopropyl) ammonium sodium-4-styrenesulfonate] (CP2) hydroxide, and poly[3-(acryloylamino)) propyl] trimethylammonium chloride-co-sodium 4-styrenesulfonate] (CP3). The copolymers were synthesized via free radical polymerization with reaction yields of 93%, 84%, and 60% respectively. Additionally, the reactivity coefficients of the monomers were 0.40, 0.34, and 0.36 respectively. The parameters investigated included pH, ionic strength, optimal polymer concentration, and maximum retention capacity. An efficient retention of ciprofloxacin (80%) was observed with a polymer/CIP molar ratio of 20:1 at pH 5.0 for CP2 and CP3. The maximum ciprofloxacin retention capacity (MRC) was determined through the enrichment method, demonstrating that the copolymer CP3 showed the highest retention capacity and the lowest desorption with respect to the other polyelectrolyte copolymers.