A continuous photocatalysis system in the degradation of herbicide

Abstract

The performance of both batch and continuous photo-catalytic reactors were studied to evaluate their capabilities in removing the sulfonyl urea herbicide of metsulfuron methyl (MM). It was found in a batch reactor, that an addition of a small amount of powder activated carbon (PAC) significantly increased the rate of degradation of MM. The continuous photocatalytic system resulted in 57% of MM removal. When a small dose of activated carbon was added in the photo-catalytic system, MM removal increased to 78-86% MM removal for detention times between of 5.25-21 min (corresponding to withdrawal rates of 10-40 mLmin -1 ). In this study, the pseudo first order rate constants of continuous photo-catalytic system revealed that shorter detention time were associated with lower rate constants. solid phase micro extraction/gas chromatography (SPME/GC) results showed that high concentrations of MM were broken down to small volatile organic compounds (VOCs) by photo-catalytic oxidation. PAC adsorbed the photo-products and increased the degradation of MM.

Preparation of Floating TiO₂/EP by Hydrothermal Method

“…Titanium dioxide(TiO 2 ) has been used widely and studied extensively as a photocatalyst to degrade various kinds of organic and inorganic pollutants [1], thanks to its low costs, non-toxic, easy availability and photo-chemical stability [2,3]. Most of applications of the photocatalyst were carried out in a slurry-type reactor, in which particles of photocatalyst suspended or were immobile.…”