ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Photo-Fenton process under sunlight irradiation for textile wastewater degradation: monitoring of residual hydrogen peroxide by spectrophotometric method and modeling artificial neural network models to predict treatment

Rayany M. R. Santana, Daniella C. Napoleão, Sérgio G. dos Santos Júnior, Rayssa K. M. Gomes, Nathália F. S. de Moraes, Léa E. M. C. Zaidan, Diego Rafael M. Elihimas, Graziele E. do Nascimento, and Marta M. M. B. Duarte

Universidade Federal de Pernambuco, Recife, Brazil

E-mail: daniella.napoleao@ufpe.br

Received: 14 October 2020  Accepted: 22 November 2020

Abstract:

Abstract

In this work, a procedure was elaborated to quantify hydrogen peroxide (H₂O₂) after degradation tests of dyes present in a synthetic textile matrix. For this purpose, based on the intensity of radiation absorption of the peroxovanadium cation, which was formed by the reaction between the oxidant and vanadate ions, ultraviolet/visible spectrophotometry technique was used. The most suitable experimental condition was composed of concentrations of 0.05 mol L⁻¹ (NH₄VO₃) and 0.3 mol L⁻¹ (H₂SO₄). The system for dye treatment involved the photo-Fenton process under simulated sunlight. In this case, concentrations of 900 mg L⁻¹ (H₂O₂) and 4 mg L⁻¹ (iron) in pH 3 were the most efficient for degrading contaminants. An efficiency of 94.49% was obtained after 180 min of reaction, the time in which the presence of the oxidant was no longer verified. The kinetic monitoring showed a two-stage degradation, described with accuracy greater than 96% by the linear and non-linear kinetic models of pseudo-first order. Additionally, the degradation under natural solar radiation was also studied, which resulted in an efficiency of 92.45% after 360 min and in the presence of the residual oxidant. Finally, via mathematical modeling and employing a Multilayer Perceptron neural network, with a 3-10-2 topology and BFGS 387 training algorithm, it was possible to predict the degradation and H₂O₂ residual concentration with an accuracy greater than 98%. Therefore, the degradation study developed and the proposed methodology for determining residual H₂O₂ proved to be adequate and capable of contributing positively to related research.

Graphic abstract

Keywords: Ammonium metavanadato; AOP; BMG model; MLP; Textile dye

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01449-y

Chemical Papers 75 (6) 2305–2316 (2021)