[Study on adsorption of bisphenol A from aqueous solution on modified activated Carbons].
A commercial activated carbon (WV A1100) was modified with nitric acid, sodium hydroxide and thermal treatment in an atmosphere of N2. Several techniques were used to characterize the physicochemical properties of these materials including BET, XPS, pH(PZC) and Boehm titration. The results indicated that the specific surface area of the W20 remarkably decreased after oxidized by nitric acid. But the amount of surface acidic oxygen-containing functional groups of the oxidized sample increased compared to the W20 and resulting in the points of zero charge (pH(PZC)) changed from 4.95 to 1.50. The changes of surface chemical properties of thermal treatment and sodium hydroxide treatment were opposite to the oxidized sample, as a result, the pH(PZC) of them was changed to near pH 7.0. However, a 43.81% surface area of W20 was also diminished by thermal treatment. Furthermore, the results of BPA adsorption indicated that the oligomerization of BPA on the surface of activated carbon could not be formed through oxidative coupling reactions in the presence of dissolved oxygen. And the data of BPA adsorption on original sample, thermal and sodium hydroxide treatment sample were fitted to the Langmuir isotherm model well. Whereas the Freundlich isotherm model described the adsorptive behavior of the oxidized sample better. In addition, the adsorption capacity of thermal treatment sample was the highest and its saturated adsorption capacity reached 526.32 mg/g. The value was three times higher than that of the oxidized sample. Combined with the results of characterization, it was found that the hydrophobic nature and zero of net charge density of carbon surface were the main factors to affect the BPA adsorption on activated carbons and the adsorption is based on pi-pi theory.
Liu
Gui-fang
GF
School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China. liuguifang@126.com
Ma
Jun
J
Guan
Chun-yu
CY
Li
Xu-chun
XC
Qin
Qing-dong
QD
Li
Gui-bai
GB
D000327:Adsorption; D001559:Benzhydryl Compounds; D002606:Charcoal; D004968:Estrogens, Non-Steroidal / Q000737:chemistry; D010636:Phenols / Q000737:chemistry*; D013499:Surface Properties; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*; D000098826:Bisphenol A Compounds
D001559:Benzhydryl Compounds; D002606:Charcoal; D004968:Estrogens, Non-Steroidal; D010636:Phenols; D014874:Water Pollutants, Chemical; C006780:bisphenol A; D000098826:Bisphenol A Compounds