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The Fered-Fenton process has been shown to be an effective method for leachate treatment, but it still faces problems of inadequate regeneration of ferrous ion. However, the use of the photoassisted Fered-Fenton process could overcome this difficulty and improve the efficiency of chemical oxygen demand (COD) removal since photoassisted Fered-Fenton process induces the production of hydroxyl radicals from the regeneration of ferrous ions and the reaction of hydrogen peroxide with UV light. As there are so many operating parameters in photoassisted Fered-Fenton process, it is necessary to develop a mathematical model in order to produce the most economical process. In the present study, a factorial design was carried out to evaluate leachate treatment by photoassisted Fered-Fenton process. The influence of the following variables: H₂O₂ concentration, Fe(2+) concentration, current density, and initial pH in the photoassisted Fered-Fenton process was investigated by measuring COD removal efficiencies after 60-min reaction. The relationship between COD removal and the most significant independent variables was established by means of an experimental design. The H₂O₂ concentration, Fe(2+) concentration, initial pH, and the interaction effect between current density and initial pH were all significant factors. The factorial design models were derived based on the COD removal efficiency results and the models fit the data well.
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http://dx.doi.org/10.1007/s11356-014-2790-2 | DOI Listing |
Chemosphere
November 2024
Institute of Environmental Engineering, National Sun Yat-sen University, Taiwan.
High-strength wastewater containing elevated levels of chloride salt and N, N-dimethylformamide (DMF) solvent was collected from manufacturing of sunscreen cream (for UVA/UVB protection) at a cosmetic factory. In evaporation process, precipitates, formed due to the high chloride content (around 160 g/L), clog the pipeline, seriously reducing the treatment efficiency. This study aimed to develop a two-stage process integrating chemical precipitation and electrochemical oxidation to specifically remove the concentrated chloride salt and organic compounds (COD >100 g/L).
View Article and Find Full Text PDFJ Environ Manage
September 2023
Federal University of Rio Grande do Sul, Hydraulic Research Institute, Postal code 15029, Av. Bento Gonçalves, 9500, CEP 91501-970, Porto Alegre, RS, Brazil.
Complex wastewater is generated during biodiesel production. We propose a new solution for the treatment of wastewater from enzymatic pretreatment of biodiesel production (WEPBP) by using a hybrid system based on the photo-Fered-Fenton process with O assistance (PEF-Fered-O). We applied response surface methodology (RSM) to determine the suitable conditions for the PEF-Fered-O process: a current intensity of 3 A, an initial solution pH controlled at 6.
View Article and Find Full Text PDFSci Total Environ
July 2023
Laboratori d'Electroquímica dels Materials i del Medi Ambient, Departament de Ciència de Materials i Química Física, Secció de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain. Electronic address:
Hydroxyl radical (OH) is considered the dominant reactive species in the electro-Fenton (EF) and Fered-Fenton (EF-Fere) processes for wastewater treatment. However, in chloride-rich media, this is arguable due to the obscure mechanisms for the oxidant speciation and pollutant degradation. Herein, the role of active chlorine and Fe(IV)-oxo species (FeO) as primary oxidizing agents in HClO-mediated Fered-Fenton (EF-Fere-HClO) process is discussed, along with the dependence of their contribution on the pollutant structure.
View Article and Find Full Text PDFChemosphere
November 2022
Postgraduate Program of Environment and Sustainable Technologies, Federal University of Fronteira Sul, Rua Jacob Reinaldo Haupenthal 1580, CEP: 97900-00, Cerro Largo, RS, Brazil.
The present work aims to fill a scientific gap regarding the treatment of wastewater from the enzymatic pretreatment of biodiesel production (WEPBP), as well as the identification of organic contaminants present in this complex matrix. Different treatment strategies were proposed for the removal of total organic carbon (TOC) and chemical oxygen demand (COD) from WEPBP. The interesting combination of O/HO/UV-Vis and electrocoagulation (EC) process was studied in two setups, with the EC process applied prior to O/HO/UV-Vis and vice versa.
View Article and Find Full Text PDFChemosphere
July 2021
Universidade Federal de São Carlos, Departamento de Química, 13565-905, São Carlos, SP, Brazil. Electronic address:
Water contamination by contaminants of emerging concern is one of the main challenges to be solved by our desired sustainable society. In the same time, different technologies for water treatment are becoming enough mature to be implemented. In this work, two different advanced oxidation processes (AOP) were investigated: i) electrochemical processes (electrochemical, photoassisted electrochemical, electro Fered-Fenton, and photo-electro Fered-Fenton - PEF-Fered) using a BDD and DSA® electrodes under UVA and UVC irradiation (9 W) and ii) solar-based AOP using four distinct oxidants (HOCl, HO, SO, HSO) in the presence or absence of Fe ions to oxidize and mineralize imidacloprid (IMD: 50 mg L) containing solutions.
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