title: Diethylenetriamine-grafted poly(glycidyl methacrylate) adsorbent for effective copper ion adsorption.
abstract: Amine-functionalized adsorbents have attracted increasing interest in recent years for heavy metal removal. In this study, diethylenetriamine (DETA) was successfully grafted (through a relatively simple solution reaction) onto poly(glycidyl methacrylate) (PGMA) microgranules to obtain an adsorbent (PGMA-DETA) with a very high content of amine groups and the PGMA-DETA adsorbent was examined for copper ion removal in a series of batch adsorption experiments. It was found that the PGMA-DETA adsorbent achieved excellent adsorption performance in copper ion removal and the adsorption was most effective at pH>3 in the pH range of 1-5 examined. X-ray photoelectron spectroscopy (XPS) revealed that there were different types of amine sites on the surfaces of the PGMA-DETA adsorbent but copper ion adsorption was mainly through forming surface complexes with the neutral amine groups on the adsorbent, resulting in better adsorption performance at a higher solution pH value. The adsorption isotherm data best obeyed the Langmuir-Freundlich model and the adsorption capacity reached 1.5 mmol/g in the case of pH 5 studied. The adsorption process was fast (with adsorption equilibrium time less than 1-4 h) and closely followed the pseudo-second-order kinetic model. Desorption of copper ions from the PGMA-DETA adsorbent was most effectively achieved in a 0.1 M dilute nitric acid solution, with 80% of the desorption being completed within the first 1 min. Consecutive adsorption-desorption experiments showed that the PGMA-DETA adsorbent can be reused almost without any loss in the adsorption capacity.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Faculty of Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260.
authors.forename: Changkun
authors.initials: C
authors.lastname: Liu
authors.forename: Renbi
authors.initials: R
authors.lastname: Bai
authors.forename: Liang
authors.initials: L
authors.lastname: Hong
mesh_terms: D000327:Adsorption; D002413:Cations, Divalent / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification
chemical_list: D002413:Cations, Divalent; D011073:Polyamines; D011109:Polymethacrylic Acids; D014874:Water Pollutants, Chemical; C005391:diethylenetriamine; C042535:polyglycidyl methacrylate; D003300:Copper