Poly (amidoamine-co-acrylic acid) copolymer: Synthesis, characterization and dye removal ability

In this paper, poly (amidoamine-co-acrylic acid) copolymer (PAC) was synthesized and its dye removal ability was investigated. The functional groups of PAC were studied using Fourier transform infrared (FTIR). Direct Red 31 (DR31), Direct Red 80 (DR80) and Acid Blue 25 (AB25) were used as model compounds. The effects of operational parameters such as adsorbent dosage, pH and salt on dye removal were evaluated. The isotherm and kinetics of dye adsorption were studied. The maximum dye adsorption capacity (Q(0)) of PAC was 3400 mg/g. 3448 mg/g and 3500 mg/g for DR31, DR80 and AB25, respectively. It was found that adsorption of DR31, DR80 and AB25 onto PAC followed with Langmuir isotherm. Adsorption kinetics of dyes followed pseudo-second order kinetics. Dye desorption tests (adsorbent regeneration) showed that the maximum dye release of 88% for DR31, 90% for DR80 and 86% for AB25 were achieved in aqueous solution at pH 12. The results showed that the PAC as a polymeric adsorbent with high dye adsorption capacity might be a suitable alternative to remove dyes from colored wastewater. (C) 2012 Elsevier B.V. All rights reserved.