Degradation of Agro-Industrial Wastewater Model Compound by UV-A-Fenton Process: Batch vs. Continuous Mode

Nuno Jorge, Ana R. Teixeira, José R. Fernandes, Ivo Oliveira, Marco S. Lucas and José A. Peres ()
Additional contact information
Nuno Jorge: Escuela Internacional de Doctorado (EIDO), Campus da Auga, Campus Universitário de Ourense, Universidade de Vigo, As Lagoas, 32004 Ourense, Spain
Ana R. Teixeira: Centro de Química de Vila Real (CQVR), Departamento de Química, Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real, Portugal
José R. Fernandes: Centro de Química de Vila Real (CQVR), Departamento de Física, Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real, Portugal
Ivo Oliveira: Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
Marco S. Lucas: Centro de Química de Vila Real (CQVR), Departamento de Química, Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real, Portugal
José A. Peres: Centro de Química de Vila Real (CQVR), Departamento de Química, Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real, Portugal

IJERPH, 2023, vol. 20, issue 2, 1-15

Abstract: The degradation of a model agro-industrial wastewater phenolic compound (caffeic acid, CA) by a UV-A-Fenton system was investigated in this work. Experiments were carried out in order to compare batch and continuous mode. Initially, batch experiments showed that UV-A-Fenton at pH 3.0 (pH of CA solution) achieved a higher generation of HO • , leading to high CA degradation (>99.5%). The influence of different operational conditions, such as H 2 O 2 and Fe 2+ concentrations, were evaluated. The results fit a pseudo first-order (PFO) kinetic model, and a high kinetic rate of CA removal was observed, with a [CA] = 5.5 × 10 −4 mol/L, [H 2 O 2 ] = 2.2 × 10 −3 mol/L and [Fe 2+ ] = 1.1 × 10 −4 mol/L ( k CA = 0.694 min −1 ), with an electric energy per order ( E EO ) of 7.23 kWh m −3 order −1 . Under the same operational conditions, experiments in continuous mode were performed under different flow rates. The results showed that CA achieved a steady state with higher space-times (θ = 0.04) in comparison to dissolved organic carbon (DOC) removal (θ = 0–0.020). The results showed that by increasing the flow rate ( F ) from 1 to 4 mL min −1 , the CA and DOC removal rate increased significantly ( k CA = 0.468 min −1 ; k DOC = 0.00896 min −1 ). It is concluded that continuous modes are advantageous systems that can be adapted to wastewater treatment plants for the treatment of real agro-industrial wastewaters.

Keywords: caffeic acid; electric energy per order; environmental impact; photo-Fenton; UV-A LEDs; winery wastewater (search for similar items in EconPapers)
JEL-codes: I I1 I3 Q Q5 (search for similar items in EconPapers)
Date: 2023
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

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