title: Removal of cadmium(II) from aqueous solutions by chemically modified maize straw.
abstract: A new regenerable adsorbent was successfully prepared by modifying maize straw (MS) with succinic anhydride in xylene. The succinylated-maize straw (S-MS) was characterized by FTIR, solid-state MAS (13)C NMR spectroscopy, SEM-EDX and point of zero charge analysis. NaS-MS was successfully obtained after deprotonating the carboxylic acid groups of S-MS by Na2CO3 solution. Batch experiments were carried out with NaS-MS for the removal of Cd(II). The effects of pH, adsorbent dosage, contact time, initial concentration and temperature were investigated. The experimental data were best described by a pseudo-second-order kinetics and Langmuir adsorption models. Thermodynamic parameters (ΔG, ΔH, and ΔS) were also calculated from data obtained from experiments performed to study the effect of temperatures. NaS-MS could be regenerated at least five times in saturated NaCl solution without any loss. Furthermore, ∼97% of adsorbed Cd(II) ions could be recovered as the metal oxide. Finally, the adsorption mechanism of NaS-MS was discussed.
authors.affiliation: State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024, China; Faculty of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Guo
authors.affiliation: State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024, China. Electronic address: zhangshf@dlut.edu.cn.
authors.forename: Shufen
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Instrument Analysis Centre, Dalian Polytechnic University, Dalian 116034, China.
authors.forename: Zinong
authors.initials: Z
authors.lastname: Kou
authors.affiliation: Faculty of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China.
authors.forename: Shangru
authors.initials: S
authors.lastname: Zhai
authors.affiliation: State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ma
authors.affiliation: Faculty of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000737:chemistry / Q000302:isolation & purification*; D010316:Particle Size; D012996:Solutions; D013387:Succinic Anhydrides / Q000737:chemistry*; D013499:Surface Properties; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*; D014992:Xylenes / Q000737:chemistry*; D003313:Zea mays / Q000737:chemistry*
chemical_list: D012996:Solutions; D013387:Succinic Anhydrides; D014992:Xylenes; D002104:Cadmium; D014867:Water; C031801:succinic anhydride
keywords: Adsorption; Cadmium; Maize straw; Succinylation