Open AccessSurface and Charge Characteristics of the Oxide/Solution Interface Towards Chromium(VI) Sorption
Author(s) -
M. M. Bhutani,
Ramesh Kumari
Publication year - 1994
Publication title -
adsorption science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.682
H-Index - 36
eISSN - 2048-4038
pISSN - 0263-6174
DOI - 10.1177/026361749401100302
Subject(s) - point of zero charge , chemistry , oxide , sorption , adsorption , inorganic chemistry , titration , surface charge , titanium oxide , bismuth , chromium , zirconium , organic chemistry
The interfacial properties of zirconium oxide, titanium oxide and bismuth oxide have been studied under various experimental conditions. The oxides were characterized by means of their pH titration curves, intrinsic dissociation constants [pKa i * (intr.), i = 1, 2) and point of zero charge (pH pzc ) in varying concentrations of KNO 3 and Na2CrO 4 solutions. The pHpzc values of all the oxide samples tended to shift to higher pH values in the presence of Na2CrO 4 solution and remain the same in the presence of KNO 3 solution. A mechanism for the sorption process is proposed proceeding through an exchange with surface OH – or H 2 O groups and is interpreted as a case of specific adsorption.