Potentiometric titrations for the characterization of functional groups on solid wastes of the olive oil production

Abstract

In this article, the identification and quantification of the acid active sites present in three solid materials, namely, olive stone, olive mill waste-water (alpeorujo), and olive tree pruning have been made, as the first step to assess their possible use as biosorbents of heavy metals. Using the continuous potentiometric titration technique, the effect of the atmosphere in the titrator and the time interval between successive additions of titrant has been studied. Potentiometric titrations on the biosorbents subjected to selective extractions (for elimination of fat compounds and polyphenols) and pretreated by acids have been also carried out. Modeling of the experimental data demonstrated that the acid-base properties of these solids were of a complex nature and could be described considering the presence of three different types of surface functional groups; two of which are presumably carboxyl and hydroxyl groups. © 2009 American Institute of Chemical Engineers Environ Prog, 2010