title: Citric Acid Enhanced Copper Removal by a Novel Multi-amines Decorated Resin.
abstract: Cu removal by a novel multi-amines decorated resin (PAMD) from wastewater in the absence or presence of citric acid (CA) was examined. Adsorption capacity of Cu onto PAMD markedly increased by 186% to 5.07 mmol/g in the presence of CA, up to 7 times of that onto four commercial resins under the same conditions. Preloaded and kinetic studies demonstrated adsorption of [Cu-CA] complex instead of CA site-bridging and variations of adsorbate species were qualitatively illustrated. The interaction configuration was further studied with ESI-MS, FTIR, XPS and XANES characterizations. The large enhancement of Cu adsorption in Cu-CA bi-solutes systems was attributed to mechanism change from single-site to dual-sites interaction in which cationic or neutral Cu species (Cu(2+) and CuHL(0)) coordinated with neutral amine sites and anionic complex species (CuL(-) and Cu2L2(2-)) directly interacted with protonated amine sites via electrostatic attraction, and the ratio of the two interactions was approximately 0.5 for the equimolar bi-solutes system. Moreover, commonly coexisting ions in wastewaters had no obvious effect on the superior performance of PAMD. Also, Cu and CA could be recovered completely with HCl. Therefore, PAMD has a great potential to efficiently remove heavy metal ions from wastewaters in the presence of organic acids.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P. R. China.
authors.forename: Chen
authors.initials: C
authors.lastname: Ling
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P. R. China.
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Liu
authors.affiliation: 1] State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China [2] Beijing Synchrotron Radiation Laboratory, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Pei
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P. R. China.
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P. R. China.
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P. R. China.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts 01003, United States.
authors.forename: Lirong
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts 01003, United States.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P. R. China.
authors.forename: Aimin
authors.initials: A
authors.lastname: Li
authors.affiliation: Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts 01003, United States.
authors.forename: Baoshan
authors.initials: B
authors.lastname: Xing
mesh_terms: D000327:Adsorption; D019343:Citric Acid / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D011073:Polyamines; D019343:Citric Acid; D003300:Copper