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.
College of Life and Science, Sichuan Agricultural University, Yaan 625014, PR China.
Yunsong
Y
Zhang
Weiguo
W
Liu
Meng
M
Xu
Fei
F
Zheng
Maojun
M
Zhao
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