Synthesis of citric acid-modified resins and their adsorption properties towards metal ions

• Published in: Royal Society open science 2018-08, Vol.5 (8), p.171667-171667
• Main Authors: Liu, Xiong, Xu, Longqi, Liu, Yaqing, Zhou, Wenqi
• Format: Article
• Language: English
• Subjects: Adsorption Capacity; Chemistry; Citric Acid; Metal Ions; Resins
• ISSN: 2054-5703; 2054-5703
• DOI: 10.1098/rsos.171667

Types of resins anchored on citric acid were synthesized and identified. The citric acid-modified resins PS-CA, PS-O-CA and PS-N-CA were synthesized by anchoring citric acid on PS-Cl, PS-OH and PS-NH2, respectively. The PS-CA, PS-O-CA and PS-N-CA were used to adsorb Fe3+, Al3+, Cu2+, Pb2+, Cd2+ and Hg2+. The influences of pH, adsorption time and metal ion concentration on the adsorption capacities of the resins were investigated. After optimization, PS-CA was a good adsorbent to Fe3+, Cu2+, Pb2+ and Cd2+ with qm values of 143.9 mg g−1, 77.4 mg g−1, 18.9 mg g−1 and 119.9 mg g−1, respectively. PS-N-CA was a good adsorbent to Al3+ and Hg2+ with qm values of 176.6 mg g−1 and 114.9 mg g−1, respectively. The adsorption kinetics and adsorption isotherm experiments indicated that the pseudo-first-order rate equation was more appropriate for characterizing the kinetic data and the Langmuir model was more suitable for fitting the equilibrium data. The reusability of the citric acid-modified resins was also evaluated and these resins exhibited considerable reusability.