Evolution of Toxicity and Mineralization during the Treatment of Diethylphthalate in Water by Ozone and Activated Carbon Coupling

Abstract

Ozone/activated carbon coupling could be an efficient method to remove micropollutants, such as phthalates, that are refractory to classical treatments. However, this wastewater-treatment process can lead to the formation of oxidation by-products that may be toxic and which also need to be removed. The aim of this work was to study the evolution of the mineralization and the toxicity of the effluent during the treatment process so as to determine the efficiency of this method and the required time of treatment. Analyses (Fourier transformed infrared spectroscopy (FTIR), thermogravimetric analyses, N2 adsorption isotherms) of the adsorbent material were performed to understand the role of activated carbon during the treatment. It is shown that depending on the activated carbon properties and the experimental conditions, a fast and complete removal of diethylphthalate, and total mineralization and detoxification of the treated solution can be obtained. Moreover, it is demonstrated that the activated carbon acts more as a reaction site than as an adsorbent, leading to an in situ renewal of the material during the process. DOI: 10.1061/(ASCE)EE.1943-7870.0000671. © 2013 American Society of Civil Engineers. CE Database subject headings: Coupling; Toxicity; Pollutants; Activated carbon; Ozone; Oxidation; Waste management. Author keywords: Ozone ðO3Þ=activated carbon (AC) coupling; Phthalates; Mineralization; Toxicity; Activated carbon renewal.