The Role of Oxidative Treatment on the Trivalent Cation Complexation Properties of Natural Organic Matter

Abstract

Humic acids (HA) which constitute the major subgroup of natural organic matter (NOM) are mainly composed of heterogeneous and polydisperse macromolecules. Considering the reactivities of the humic moieties towards the common coagulants during physico-chemical treatment of drinking water, different pre-oxidation conditions could exhibit various changes in humic acid structure leading to diverse reactivities towards the trivalent cations. The aim of this study was to evaluate the effects of the oxidative pre-treatment schemes applied by ozonation, TiO

The Influence of Surface Alumina and Silica on the Photocatalytic Degradation of Organic Pollutants

“…Further, the relative strengths of binding of silicate, sulphate and phosphate to hydroxyl aluminium species is pH dependent; at pH > 5 silicate binds more strongly than sulphate and at pH > 6.6 silicate binds more strongly than phosphate [21]. Further perturbation occurs because aluminium in natural water may be complexed by naturally occurring organic matter, e.g., humic acids [22] and the efficiency of this complexation may be changed by the presence of other ions [23] or oxidative pre-treatment such as ozonation [24] Therefore, instead of attempting to mimic the mechanisms that take place in natural waters, the oxides have been deposited on the TiO 2 by well defined routes. "Alumina" coatings of series 1A were prepared by precipitation of a hydrous alumina onto a polyphosphate dispersed suspension (30 g dm ) of rutile in water [15].…”