INVESTIGADORES
CAREGNATO Paula
capítulos de libros
Título:
REACTIVITY OF INORGANIC RADICALS AND EXCITED TRIPLET STATES IN COLLOIDAL SILICA SUSPENSIONS
Autor/es:
VALERIA B. ARCE; PAULA CAREGNATO; MONICA C. GONZALEZ; DANIEL O. MARTIRE
Libro:
Silica Nanoparticles: Preparation, Properties and Uses
Editorial:
Nova Science Publishers, Inc.
Referencias:
Lugar: Hauppauge NY; Año: 2011; p. 39 - 80
Resumen:
Aquatic photochemistry studies the degradation of contaminants induced by
light (either terrestrial sunlight or artificial light used in engineered water
treatment systems). In addition to the direct photolysis or direct
phototransformation route there exist a variety of photochemical reactions
involving chromophores already present in natural waters and producing reactive
species that initiate the degradation of the target contaminant (indirect
phototransformation). Since the main absorber of light in natural waters is
colored dissolved natural organic matter (CDOM), the excited triplet states of
CDOM are involved in the indirect phototransformation of contaminants. However,
irradiation of CDOM leads to the formation of other species, such as singlet
molecular oxygen, solvated electrons, hydrogen peroxide, and hydroxyl radicals
among others. Most of these species are able to initiate chemical reactions in
which undesirable organic components are attacked and ultimately destroyed,
thus providing a mechanism for self-cleansing of the water sources.
Silica is a ubiquitous material in the environment, which is present in
great amounts in natural waters. This material is an excellent sorbent of
contaminants, as well as reactive species involved in their degradation. Thus,
it is relevant to know the mechanisms of the reactions that take place at the
silica/water interfaces.