Science and Technology Production
Actas del Congreso. International Conference EA3G 2013. Ozone and related oxidants. - Degradation of n-Butyl Benzyl Phthalate Using O3/UV
Congress
Date:
2013Publishing House and Editing Place:
Actas del CongresoSummary *
Diesters of phthalic acid, commonly referred to as phthalates (PAEs) represent a large family of chemicals most widely used as plasticizers, primarily in the production of polyvinyl chloride (PVC) resins, adhesives, and cellulose film coating to improve mechanical properties of the plastic resin, particularly flexibility. PAEs have been classified as priority pollutants and endocrine disrupting compounds by the US EPA and similar regulatory agencies in several other countries. n-Butyl benzyl phthalate (BBP) is one of the most frequently identified phthalates in diverse environmental samples including groundwater, river water, drinking water, ocean water, soil, lake sediment and marine sediments [1]. BBP was examined for its estrogenic properties both in vivo and in vitro and was considered as one of the major endocrine disrupting chemicals. Several studies have been conducted for the elimination of PAEs by Advanced Oxidation Processes such as TiO2/UV, H2O2/UV, Ozonation, among others.Ozone is widely used in drinking water treatment for organic matter decomposition and microbiology disinfection. Several kinds of phthalates were also degraded by this technology. However, no report about BBP degradation by O3 or O3/UV process could be found in the literature. In this work, effects of ozone concentration, pH, UV radiation and presence of scavengers on the degradation of BBP by O3/UV process were studied. The occurrence of direct photolysis was also evaluated. The major intermediates of the BBP degradation were identified, and a primary degradation mechanism was proposed. The effects of the different experimental variables on BBP degradation was determined. This is the first step to the proposal of a mathematical model for the degradation kinetics of BBP by means of the O3/UV process.Effects of ozone concentration, pH, UV radiation and coexisting substances on the degradation of BBP by O3/UV process were investigated. It was determined that: (i) an increase in dissolved O3 concentration enhances the degradation of BBP; (ii) the presence of t-BuOH decreases the reaction rate (iii) the use of O3/UV is much more effective than O3 alone for BBP oxidation, (iv) The efficiency of BBP degradation increased when pH value increased from 4.0 to 10.0. Major intermediates of BBP degradation were identified, and a primary degradation mechanism was proposed. The results obtained are helpful for the treatment of water contaminated with BBP. Information provided by the agent in SIGEVAKey Words
UVradiationBenzyl butyl phthalateOzoneDirect and indirect oxidation