Characterization and adsorption mechanism of Zn2+ removal by PVA/EDTA resin in polluted water.
Batch adsorption experiments were conducted using a PVA/EDTA resin as an adsorbent to adsorb Zn(II) ions from single component system in which experimental parameters were studied including solution pH, contact time, adsorbent dose and initial metal ions concentration. The equilibrium isotherms were determined at pH 6 under constant ionic strength and at different temperatures. The results showed that the maximum removal of Zn(II) (99.8%) with 1 g L(-1) of sorbent was observed at 40 mg L(-1) at an initial pH value of 6. Removals of about 60-70% occurred in 15 min, and equilibrium was attained at around 30 min. The equilibrium data for the adsorption of Zn(II) on PVA/EDTA resin was tested with various adsorption isotherm models among which three models were found to be suitable for the Zn(II) adsorption. In addition, the kinetic adsorption fitted well to the pseudo-second-order model and the corresponding rate constants were obtained. Thermodynamic aspects of the adsorption process were also investigated. Furthermore a higher desorption efficiency of Zn(II) from the PVA/EDTA resin using acid treatment was available by more than 95%.
State Key Laboratory of Applied Organic Chemistry, College of Resources and Environment, College of Chemistry and Chemical Engineering, Institute of Biochemical Engineering & Environmental Technology, Lanzhou University, Lanzhou 730000, PR China.
Yun
Y
Zhang
Yanfeng
Y
Li
Liu-qing
LQ
Yang
Xiao-jie
XJ
Ma
Li-yuan
LY
Wang
Zheng-fang
ZF
Ye
D000042:Absorption; D000465:Algorithms; D003188:Composite Resins / Q000737:chemistry*; D004492:Edetic Acid / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D012996:Solutions; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*; D015032:Zinc / Q000302:isolation & purification*
D003188:Composite Resins; D007220:Industrial Waste; D012996:Solutions; D014874:Water Pollutants, Chemical; D011142:Polyvinyl Alcohol; D004492:Edetic Acid; D015032:Zinc