Water-soluble polymers with the ability to remove amoxicillin as emerging pollutant from water

Abstract

The release of pharmaceutical products, especially antibiotics, into natural waters has become one of the main environmental concerns in recent years. Amoxicillin (AMX) is widely used in the treatment of human infections and is commonly detected in domestic and industrial wastewater. This work aims to study the elimination of AMX using functional water-soluble polymers (FSP) assisted by ultrafiltration membranes through the washing and enrichment method. For this, three polymers with different charge ratios (cationic:anionic) of 2:1 (FSP-1), 1:2 (FSP-2) and 1:1 (FSP-3) were synthesized. Polymers were synthesized by radical polymerization and characterized by FTIR and 1 H-NMR spectroscopy. Removal studies were carried out evaluating variables such as pH, ionic strength, concentration of FSP and AMX. Through the washing method, it was found that the conditions with the highest removal efficiency for FSP-1 was 97% at pH 11.0, molar ratio (40:1), and 100 mg L − 1 AMX, FSP-2 of 72% at pH 3.0, molar ratio (40:1), and 40 mg L − 1 of AMX; while FSP-3 was 82% at pH 7.0, molar ratio (100:1), and 40 mg L − 1 of AMX. Meanwhile, the maximum removal capacity obtained by the enrichment method was 705.8, 385.3, and 397.8 mg g − 1 FSP-1, FSP-2 and FSP-3, respectively. The results suggest that FSPs coupled to ultrafiltration membranes are an alternative for the environmental remediation of antibiotic-type contaminants such as AMX.