Application of Modified Polyurethane Foam by Dehpa to Remove Sulfamethoxazole from Aqueous Environments

In recent years, the environmental risks caused by the use of antibiotics have garnered increasing attention. Pollution of water resources in the environment and the presence of antibiotics in large quantities increase drug resistance in living organisms. The routine treatment carried out by conventional wastewater treatment plants does not eliminate the total antibiotic load. Cost effective and environmentally sound processing technologies must be developed to deal with this challenge. One such widely used antibiotic is Sulfamethoxazole (SMX). The Sulfonamide-based antibacterial drug is widely applied to human or animal medicines to kill bacteria. In this study, the potential of modified polyurethane foam was investigated to remove SMX from contaminated waters. The polyurethane foam was improved by bis (2-ethylhexyl) phosphoric acid (DEHPA) solution for better performance. The solution of DEHPA with a concentration of 1 M in methanol had the best result. The improved adsorbent was then examined for assessment of its ability to eliminate SMX from aqueous solution in different conditions (adsorbent dosage, pH of the solution, contact time between adsorbent and adsorbate, and initial SMX concentration). The results showed that the best conditions to remove SMX, pH= 5 with the yield of 80% ± 5, initial concentration 10 ppm (50 mL), shaking time 30 minutes were achieved by using 5 g of modified polyurethane. Experimental data showed that kinetics and isotherms for the adsorption process matched with pseudo-second-order, pseudo-first-order, and Langmuir more pertinent, respectively. Polyurethane foam was recognized as a cost-effective adsorbent for SMX removal.