Treatment of 2,4-Dichlorophenol by Solar Photocatalysis: Comparison of Coupled Photocatalytic-Active Carbon vs. Active Carbon

Abstract

The photocatalytic oxidation of 2,4-Dichlorophenol (DCP), using TiO2 suspensions under solar radiation, has been studied at pilot-plant scale at the Plataforma Solar de Almerı́a (PSA). This compound is used as a model to demonstrate the practical application of the treatment. Total Organic Carbon (TOC) analysis is applied to confirm the total mineralization of the contaminants. The pilot plant has a volume of 247 L and consists of 9 m2 of CPC modules (with transparent tubes) connected to a recirculation tank. DCP at 20, 50 and 200 mg/L is completely photodegraded in the presence of 200 mg/L of TiO2, but mineralization is slow when organics concentration is small. The results obtained from these experiments have been used to decide the dimensions of a solar photocatalytic plant for treating wastewater contaminated with different concentration of DCP. Due to the slow kinetic obtained in the photodegradation last steps, a combination with GAC treatment is proposed. Besides, this article attempts to compare the advantages, disadvantages and costs of photocatalytic treatment, versus other more conventional technologies such as active carbon adsorption.