Remove hazardous textile dyes using polyampholytes derived from polyethyleneimine

Abstract Many processes can be used to remove toxic pollutants from wastewater. Adsorption process has been an important issue in water pollution control. In this research, work describes a facile procedure for synthetizing two polyampholytes through chemical modification of polyethyleneimine and their efficacy as adsorbent materials. The presence of amino and sulfonic acid groups in both polyelectrolytes gives them the property of ionic exchange, classifying them as polyampholytes. The adsorptive properties of both polyelectrolytes were evaluated in aqueous solutions with two acid dyes, Congo Red (DR28) and Eriochrome Black (MB11), and two basic dyes, Malachite Green (BG4) and Methylene Blue (BB9). These dyes possess anionic or cationic groups that interact electrostatically with these new polyampholytes that allow the adsorption. The kinetic study of adsorption for both polyelectrolytes, with all dyes, fits well with the pseudo second order model, demonstrating the chemisorption process. The adsorption percentage of both polyelectrolytes with cationic dyes is closer to 100%. The polyampholytes show adsorption capacity values ranging, with cationic dyes, from 270 to 416 mg g −1 , as conventional ion exchange resins.