The Influence of the Configuration of Two Electrochemical Reactors on the Process of Removing Atrazine from Water

Juan Nápoles-Armenta,Juan Antonio Vidales-Contreras,Edgardo Martínez-Orozco,Pablo Gortáres-Moroyoqui,Luis Alonso Leyva-Soto,Lilian Alejandra Salcedo-Gastelum,Edna Rosalba Meza-Escalante,Lourdes Mariana Díaz-Tenorio,Celestino García-Gómez,Celia De La Mora-Orozco

doi:10.3390/su13095267

Abstract

In Mexico, atrazine is widely used in agriculture to control broadleaf weeds. The objective of this research was to compare atrazine removal in water and energy consumption between an up-flow cylinder electro-oxidation reactor (UCER) and an up-flow rectangular electro-oxidation reactor (URER) using the response surface methodology. In each reactor, two titanium (Ti) mesh electrodes (cathodes) and one Titanium-Lead Dioxide (Ti-PbO2) mesh electrode (anode). Current intensity effects, electrolysis treatment time, and recirculation flow were evaluated. Synthetic water with 5 mg/L atrazine content was used. Optimum atrazine removal values were obtained at 2 A electric current, 180 min of treatment time, and 200 mL/min recirculation rate for both reactors: in these conditions an atrazine removal of 77.45% and 76.89% for URER and UCER respectively. However, energy consumption showed a significant difference of 137.45 kWh/m3 for URER and 73.63 kWh/m3 for UCER. Regarding energy efficiency, a 60% atrazine removal was reached in both reactors using less energy for UCER at (1.5 A–135 min–150 mL/min–25.8 kWh/m3) and for URER at (0.66 A–135 min–150 mL/min–20.12 kWh/m3).

Highlights

The highest removal was 76.89% in the up-flow cylindrical electro-chemical reactor (UCER) and 77.45% in the up-flow rectangular electro-oxidation reactor (URER), both values achieved with a current intensity of 2 amperes, min of duration of electrolysis and a flow of recirculation of 200 milliliters per minute
The atrazine removal in this research were lower (77.45% and 76.89% for URER and UCER respectively) than the reported by Zadaka et al [22], (96%) using an electrochemical sensor based on silver nanoparticles (AgNPs), the process uses nanoparticles in different electrodes to the used in this study, and even with superior removal this process represents a higher cost and potential further processes
Turan et al [24] used different electrodes than the used in this research, but it coincides in the significant variables with current intensity values coinciding in 2A with this research and with less treatment time, does not report energy consumption

Summary

Introduction

Industrial development has led to numerous synthetic chemical products manufactured, the production of which increase the presence of potentially hazard pollutants in the environment. Mining activities, manufacturing processes, combustion, and pesticides are the main sources for heavy metals concentration discharged in waterbodies [1]. The presence of various organic compounds generates problems in agricultural, urban, and industrial wastewater [2]. It is common to talk about emerging contaminants such as pharmaceuticals, personal care products, surfactants, industrial additives, pesticides, herbicides, 4.0/).

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