Kaolinite adsorption-regeneration system for dyestuff treatment by Fenton based processes

Emilio Rosales; Delia Anasie; Marta Pazos; Iuliana Lazar; M Angeles Sanromán

doi:10.1016/j.scitotenv.2017.11.301

Kaolinite adsorption-regeneration system for dyestuff treatment by Fenton based processes

Sci Total Environ. 2018 May 1:622-623:556-562. doi: 10.1016/j.scitotenv.2017.11.301. Epub 2017 Dec 13.

Authors

Emilio Rosales¹, Delia Anasie², Marta Pazos³, Iuliana Lazar⁴, M Angeles Sanromán³

Affiliations

¹ Department of Chemical Engineering, University of Vigo, Campus As Lagoas-Marcosende, 36310 Vigo, Spain. Electronic address: emiliorv@uvigo.es.
² Department of Chemical Engineering, University of Vigo, Campus As Lagoas-Marcosende, 36310 Vigo, Spain; Faculty of Engineering, "Vasile Alecsandri" University of Bacau, Calea Marasesti 157, 600115 Bacau, Romania.
³ Department of Chemical Engineering, University of Vigo, Campus As Lagoas-Marcosende, 36310 Vigo, Spain.
⁴ Faculty of Engineering, "Vasile Alecsandri" University of Bacau, Calea Marasesti 157, 600115 Bacau, Romania.

PMID: 29223079
DOI: 10.1016/j.scitotenv.2017.11.301

Abstract

The regeneration and reuse of adsorbents is a subject of interest nowadays in order to reduce the pollution and the wastes generated in the adsorption wastewater treatment. In this work, the regeneration of the spent kaolinite by different advanced oxidation processes (Fenton, electro-Fenton and electrokinetic-Fenton) was evaluated. Initially, it was confirmed the ability of a low cost clayey material, kaolinite, for the adsorption of model dye such as Rhodamine B showing Freundlich isotherm fitting. Then, the regeneration and consequent degradation of the pollutant in the adsorbent by Fenton based processes was carried out. The role of different parameters affecting the regeneration process (H₂O₂:Fe²⁺ ratio, liquid:solid ratio) were evaluated. Working at 100:1 H₂O₂:Fe²⁺ ratio and 30min near complete dye removal (around 97%) from kaolinite was obtained by Fenton treatment. After that, a two-stage treatment for adsorption-regeneration was evaluated during five treatment cycles demonstrating its viability for regeneration of the adsorbent through dye degradation. Based on the successful application of Fenton technique, the improvement of the treatment by electro-Fenton and electrokinetic-Fenton were studied for different solid:liquid ratios achieving satisfactory regeneration values.

Keywords: Adsorption-degradation system; Electro-Fenton; Electrokinetic-Fenton; Fenton; Spent adsorbent.