Reaction kinetics formulation with explicit radiation absorption effects of the photo-Fenton degradation of paracetamol under natural pH conditions

• Published in: Environmental science and pollution research international 2021-05, Vol.28 (19), p.23946-23957
• Main Authors: Giménez, Bárbara N., Schenone, Agustina V., Alfano, Orlando M., Conte, Leandro O.
• Format: Article
• Language: English
• Subjects: Absorption; Advanced Oxidation/Reduction Technologies: An Perspective from Iberoamerican Countries; Analgesics; Aquatic Pollution; Aqueous solutions; Atmospheric Protection/Air Quality Control/Air Pollution; Benzoquinone; Catalysts; Degradation; Design of experiments; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Experimental design; Flat plates; Hydrogen peroxide; Hydroquinone; Intermediates; Mathematical models; Oxalic acid; Paracetamol; Parameter estimation; pH effects; Photon absorption; Radiation; Radiation absorption; Radiation measurement; Reaction kinetics; Reaction mechanisms; Reaction time; Solar simulators; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-020-11993-5

The degradation of paracetamol (PCT) in an aqueous medium using the Fenton and photo-Fenton reactions was investigated. The aim of this research was the development of a kinetic model based on a reaction mechanism, which includes two main intermediates of PCT degradation and the local volumetric rate of photon absorption (LVRPA). Ferrioxalate was used as a catalyst and the working pH was adjusted to 5.5 (natural pH). Experimental work was planned through a D-optimal experimental design and performed in a flat plate reactor irradiated by a solar simulator. Hydrogen peroxide (HP) concentration, reaction temperature, and radiation level were the operating parameters. The photo-Fenton reaction allowed to reach a minimum relative PCT concentration of 2.01% compared to 5.04% achieved with Fenton reaction. Moreover, the photo-Fenton system required a 50% shorter reaction time and lower HP concentration than in dark conditions (90 min and 189 mg L -1 vs. 180 min and 334 mg L -1 , respectively). The experimental results were used to estimate the kinetic parameters of the proposed kinetic model employing a nonlinear, multi-parameter regression method. The values obtained from the normalized root-mean-square error (14.52, 1.96, 4.36, 13.16, and 8.72 % for PCT, benzoquinone, hydroquinone, HP, and oxalate, respectively) showed a good agreement between the predicted and experimental data.