%0 Journal Article
%T Efecto del pH en la Degradaci車n Fotocatal赤tica de Materia Org芍nica Natural Effect of pH on the Photocatalytic Degradation of Natural Organic Matter
%A Sergio H Valencia
%A Juan M Mar赤n
%A Gloria M Restrepo
%J Informaci車n Tecnol車gica
%D 2011
%I Centro de Informaci車n Tecnol車gica
%X Se ha estudiado el efecto del pH en la degradaci車n fotocatal赤tica de materia org芍nica natural del agua de un ecosistema l谷ntico, empleando di車xido de titanio comercial en suspensi車n y un simulador solar UV. Para el seguimiento de la degradaci車n y la caracterizaci車n de la materia org芍nica natural se us車 cromatograf赤a de exclusi車n de tama o, con un detector de carb車n org芍nico disuelto y un detector ultravioleta a una longitud de onda A=254 nm, y espectrofotometr赤a UV-Vis. Se encontr車 que la cin谷tica de la reacci車n es alta a un pH por debajo del punto isoel谷ctrico del fotocatalizador y disminuye a un pH por encima del punto isoel谷ctrico. Adem芍s, la fotocat芍lisis se da por la alteraci車n de la distribuci車n de las masas moleculares, especialmente por la degradaci車n de compuestos de alta masa molecular a compuestos de baja masa molecular, antes de su mineralizaci車n. The effect of pH on the photocatalytic degradation of natural organic matter in water from a lentic ecosystem using commercial titanium dioxide in suspension and a solar UV simulator was studied. The degradation monitoring and natural organic matter characterization was followed by size exclusion chromatography with dissolved organic carbon and ultraviolet detection at wave length A=254 nm, and UV-Vis spectrophotometry. It was found that at pH below the isoelectric point of the photocatalyst, the kinetics of the reaction is high and with a pH above the isoelectric point the reaction kinetics decreases. Also, the photocatalysis is given by an alteration of the molecular weight distribution especially for the degradation of high molecular weight compounds to low molecular weight compounds, before their mineralization.
%K materia org芍nica natural
%K fotocat芍lisis heterog谷nea
%K di車xido de titanio
%K cromatograf赤a
%K natural organic matter
%K heterogeneous photocatalysis
%K titanium dioxide
%K chromatography
%U http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-07642011000500008