Removal of Hexavalent Chromium and Some Organic Compounds Using Two Combined Photo-Fenton and Electrochemical Techniques
Abstract
The tanning industries have been of great relevance in the economic sector of our country since the 17th century because they contribute to the export and manufacture of leather. From a socioeconomic standpoint, it is beneficial for society; however, this type of industry generates organic and inorganic pollutants that affect the effluents and the ecosystem of the sector. Therefore, advanced oxidation processes such as Fenton and photo-Fenton and electrochemical techniques were addressed in this research. For this, Fenton and photo-Fenton tests were carried out using samples of the effluents from the WWTP (wastewater treatment plant) of the tanneries and they were reacted with known concentrations of hydrogen peroxide and ferrous sulfate (Fenton Reagent) and in the case of photo-Fenton, additionally using an ultraviolet light lamp for 1 hour, obtaining 92.50% turbidity removal percentages, 100% color, 78% COD, and 66% TOC. In the case of electrochemical techniques, cyclic voltammetry, linear scanning voltammetry, and chronoamperometry techniques were used to remove the hexavalent chromium present in the wastewater. Solutions with concentrations within the range of real potassium dichromate wastewater in 0.5M H2SO4 solution were prepared using a graphite cloth as the working electrode, an Hg/HgSO4 reference electrode, and a graphite rod counter electrode, obtaining a 99.54% hexavalent chromium reduction using these techniques. Finally, it can be concluded that the advanced Fenton and photo-Fenton oxidation processes were very efficient in the removal of organic compounds present in the effluents of the tanneries. In addition, when combined with electrochemical techniques, the decontamination process is optimized because it reduces the production of heavy metals such as hexavalent chromium, which are dangerous to human health and the ecosystem. This research provided a great achievement from the academic, economic, and environmental viewpoints since these processes are economical and environmentally friendly.
Keywords: tanneries, Fenton, photo-Fenton, electrochemical techniques, hexavalent chromium.
https://doi.org/10.55463/issn.1674-2974.50.10.10
Full Text:
PDFReferences
UGUR K, OMER A, & TALHA, G. Reduction of COD in wastewater from an organized tannery industrial region by Electro-Fenton process. Journal of Hazardous Materials, 2007, 143: 33–40.
SHAHID M, SHAMSHAD S, RAFIQ M, et al. Chromium speciation, bioavailability, uptake, toxicity and detoxification in soil-plant system: A review. Chemosphere, 2017, 178: 513–533. https://doi.org/10.1016/j.chemosphere.2017.03.074.
DE VASCONCELOS T A R, , DE ALMEIDA D. F., HUNGRIA M, et al. Complete genome sequence of Chromobacterium violaceum reveals remarkable bacterial adaptability. Proceedings of the National Academy of Sciences of the United States of America, 100(20): 11660–11665. https://doi.org/10.1073/pnas.1832124100
ZHITKOVICH A. Chromium in drinking water: Sources, metabolism, and cancer risks. Chemical Research in Toxicology, 2011, 24(10): 1617–1629. https://doi.org/10.1021/tx200251t
MOREIRA F C, BOAVENTURA R A R, BRILLAS E, & VILAR V J P. Electrochemical advanced oxidation processes: A review on their application to synthetic and real wastewaters. Applied Catalysis B: Environmental, 2017, 202: 217–261. https://doi.org/10.1016/j.apcatb.2016.08.037.
GANIYU S O, HUONG LE T X, BECHELANY M, et al. A hierarchical CoFe-layered double hydroxide modified carbon-felt cathode for heterogeneous electro-Fenton process. Journal of Materials Chemistry A, 2017, 5(7): 3655–3666. https://doi.org/10.1039/c6ta09100h.
ANDREOZZI R, CAPRIO V, INSOLA A, & MAROTTA R. Advanced oxidation processes (AOP) for water purification and recovery. Catalysis Today, 1999, 53(1): 51–59. https://doi.org/10.1016/S0920-5861(99)00102-9
LAINE D, & CHENG I. The destruction of organic pollutants under mild reaction conditions: A review. Microchemical Journal, 2007, 85: 183-193. https://doi.org/10.1016/j.microc.2006.07.002.
ZAVISKA, F., DROGUI, P., MERCIER, G. & BLAIS, J.-F. Procédés d’oxydation avancée dans le traitement des eaux et des effluents industriels: Application à la dégradation des polluants. Journal of Water Science, 2009, 22: 535-564. https://doi.org/10.7202/038330ar
HERRMANN J-M. Heterogeneous photocatalysis: state of the art and present applications. Topics in Catalysis, 2005, 34: 49-65
TARR M A. Chemical Degradation Methods for Wastes and Pollutants. Environmental Science and Pollution Control Series, 2003, 26: 165-200. https://doi.org/10.1201/9780203912553.
KONSTANTINOU I K, & ALBANIS T A. Photocatalytic transformation of pesticides in aqueous titanium dioxide suspensions using artificial and solar light: intermediates and degradation pathways. Applied Catalysis B: Environmental, 2003, 42: 319-335
ČERNIGOJ U, LAVRENČIČ ŠTANGAR U, & TREBŠE P. Evaluation of a novel Carberry type photoreactor for the degradation of organic pollutants in water. Journal of Photochemistry and Photobiology A: Chemistry, 2007, 188: 169-176
ROSENFELDT E, LINDEN K, CANONICA S, & GUNTEN U. Comparison of the efficiency of OH radical formation during ozonation and the advanced oxidation processes O3/H2O2 and UV/H2O2. Water Research, 2007, 40: 3695-3704. https://doi.org/10.1016/j.watres.2006.09.008.
PLAKAS K V, KARABELAS A J, SKLARI S D, & ZASPALIS V T. Toward the development of a novel electro-fenton system for eliminating toxic organic substances from water. Part 1. in situ generation of hydrogen peroxide. Industrial and Engineering Chemistry Research, 2013, 52(39): 13948–13956. https://doi.org/10.1021/ie400613k.
OTURAN M A. Ecologically effective water treatment technique using electrochemically generated hydroxyl radicals for in situ destruction of organic pollutants: Application to herbicide 2.4-D. Journal of Applied Electrochemistry, 2000, 30(4): 475–482. https://doi.org/10.1023/A:1003994428571
BRILLAS E, SIRÉS I, & OTURAN M A. Electro-Fenton Process and Related Electrochemical Technologies Based on Fenton’s Reaction Chemistry. Chemical Reviews, 2009, 109(12): 6570–6631. https://doi.org/10.1021/cr900136g
FILIK H, & AVAN A. Dextran modified magnetic nanoparticles based solid phase extraction coupled with linear sweep voltammetry for the speciation of Cr(VI) and Cr(III) in tea, coffee, and mineral water samples. Food Chemistry. 2019, 292: 151-159. https://doi.org/10.1016/j.foodchem.2019.04.058.
Refbacks
- There are currently no refbacks.