Heterogeneous Fenton-like oxidation of synthetic phenolic effluents in a continuos reactor, using alumina-based materials

MASSA, PAOLA; FENOGLIO, ROSA; HAURE, PATRICIA; DI LUCA, CARLA

Praga

Conferencia; 5th European Conference on Environmental Applications of Advanced Oxidation Processes ? EAAOP5; 2017

University of Chemistry and Technology

A relatively high concentrated phenolic aqueous solution (1 g/L) was used as synthetic effluent. The heterogeneous Fenton-like oxidation was carried out over a highly dispersed pelletized Fe(III)-Al2O3 catalyst (6 wt% Fe, dp = 2.5 mm). To improve catalytic performance, different simple preparation strategies were combined: two-stage impregnation of iron citrate, calcination at 900 ºC and acid washing step. Solid samples were characterized by several techniques: N2 physisorption, XRD, SEM?EDS, XPS and Mössbauer. The reactor consists in a glass jacketed column (Di = 2.3 cm; L = 21 cm), operating under atmospheric pressure. The total flow rate was adjusted in the range of Q = 1.2-5.4 mL/min. The catalytic performance was monitored in terms of phenol and Total Organic Carbon (TOC) removal, hydrogen peroxide consumption and pH evolution. Several variables, such as reaction temperature and residence time, have been studied in order to optimize the operation conditions for phenol mineralization under continuous mode. The objective was to imrpove the performance of the oxidation process; reaching higher mineralization levels, making best use of the hydrogen peroxide supplied and minimizing the impact of active phase leaching. Under the best operation condition, total phenol abatement and remarkable TOC reduction of 90% were achieved, with a high H2O2 consumption efficiency (η = 76 %) and low Fe leaching (< 3 ppm). After 50 h of usage, the catalyst retained high conversion levels and the development of deactivation processes might be due to refractory organic intermediates adsorbed onto the catalyst surface.