Study of the mechanisms of Cu2+ biosorption by ethanol/caustic-pretreated baker's yeast biomass.
Baker's yeast biomass was pretreated by ethanol and caustic soda, and then the pristine baker's yeast, ethanol pretreated baker's yeast (ethanol-baker's yeast) and caustic soda pretreated baker's yeast (caustic-baker's yeast) were utilized as biosorbents to adsorb Cu(2+) in aqueous solution. The influence of different parameters on Cu(2+) uptake by the three biomasses, such as initial Cu(2+) concentration, initial pH of solution, contact time and temperature, was studied. The mechanism of Cu(2+) binding by biomass was investigated by a number of techniques. Evidence from potentiometric titration revealed that the concentration of carboxyl and amino groups is higher on the caustic and ethanol-baker's yeast compared to the pristine baker's yeast and FTIR spectra confirmed carboxyl, and amino groups on the surface of baker's yeast could be available for characteristic coordination bonding with Cu(2+). In addition, SEM and Zeta potential of the three samples show that caustic and ethanol-pretreatment resulted in the change of baker's yeast surface structure and charge which is relative to adsorption. These results demonstrate that the increase of biosorption capacity for Cu(2+) by ethanol and caustic-baker's yeast was attributed to the increase and exposure of carboxyl and amino groups on the surface of biomass sample.
Zhang
Yunsong
Y
College of Life and Science, Sichuan Agricultural University, Yaan 625014, PR China.
Liu
Weiguo
W
Xu
Meng
M
Zheng
Fei
F
Zhao
Maojun
M
D000327:Adsorption; D000468:Alkalies / Q000737:chemistry; D018533:Biomass; D003300:Copper / Q000737:chemistry*; D019327:Copper Sulfate / Q000737:chemistry; D004563:Electrochemistry; D000431:Ethanol / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D015233:Models, Statistical; D010316:Particle Size; D011199:Potentiometry; D012441:Saccharomyces cerevisiae / Q000737:chemistry*; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013696:Temperature; D014867:Water
D000468:Alkalies; D012996:Solutions; D014867:Water; D000431:Ethanol; D003300:Copper; D019327:Copper Sulfate