Determinación cinética de consumo de ozono disuelto en agua

Abstract

A method based on residual ozone decay by UV spectrofotometry (256 nm) is proposed. This method allows the deterrnination of the apparent rate constan! (kr) for a given water, with high accuracy and relative easiness respect other methods. A comparison of different methods was carried out, the decol­orization of in digo by ozone method ( 600 nm) and empirical relationships, where overall kinetic of ozone decay is a function of surrogate water quality parameters as pH, total alkalinity and total organic carbon ( these are reported on the literature ); different results were confirmed and disadvantages of these methods were pointed out. The low krvalues of the drinking filtrated (byactivated car bon) water correspond to the high water 1 quality. and high alkalinity value. The kr values are between 1,69 and 6,12 h-(with a standard error less to 10 %) and these correspond with the criterion that clean waters have values less than 5 h-1. Besides, overall kinetic of ozone decay was determined for ground waters from different sources, this permitted to analyze the effectiveness of the new method and the relationship between water quality, dissolved ozone consurnption and half-Iife of the value of the residual ozone concentration. The knowledge of these pararneters is useful to design ozone water treatment systems, and it permits the improvement of ozone process efficiency of systems in service.