Decolorizing Methyl Orange by Fe-Electrocoagulation Process – A Mechanistic Insight

Sara Irki

doi:10.11648/j.ijec.20180201.14

Abstract

The aim of this work is to study the removal of methyl orange (MO) using electrocoagulation (EC) process. An electrochemical cell consisting of two iron electrodes, with 22.5 cm<sup>2</sup> as an active surface, is used. Operating conditions are optimized such as nature and concentration of the supporting electrolyte, current density, pH, inter-electrode distance, MO concentration, and the connection mode. The decolorization degree obtained after 15 min of EC reached 83% at pH 7.25 with a current density of 64 A/m<sup>2</sup>. Depending on pH, three EC process mechanisms are suggested and less or more significant removal performances are obtained in these tests. The Scanning Electron Microscopy (SEM) observations show that the flocs formed by the EC process have two distinct morphologies: a lumpy structure and an amorphous structure, formed by particles of various sizes. The Energy Disperses X-ray (EDX) analysis of the surface of the flocs formed by the EC process shows a spectrum with levels of major elements of iron, oxygen and chloride, as well as carbon, sodium and aluminum are detected as minor elements. As proved in terms of MO elimination through this research and due to its several advantageous, EC process would find its convenient place in wastewater treatment technology.

Highlights

Textile and printing industries are considered as the main polluting sectors because of their elevated leakage bulk of dye-containing polluted water [1,2,3]
The impacts of supporting electrolyte (SE) concentration (CSE), CMO, J, and pH of the methyl orange (MO) solution were examined in order to determine the optimum operating conditions for the MO maximum removal performance
In the pH range 4 to 7.25, the results show that the increase in the decolorization efficiency starts after 12 min and the recorded rate is higher than 70% and the maximum rate is reached around 19 min

Summary

Introduction

Textile and printing industries are considered as the main polluting sectors because of their elevated leakage bulk of dye-containing polluted water [1,2,3]. Similar types of dye wastewaters are known for their acute color, elevated organic concentration and unvarying chemical configuration because of the presence of azo groups [6]. They are harmful and refractory to biological decay. As a an azo chemical, methyl orange (MO) is frequently employed as a coloring chemical product in numerous cases, like textile, paint, ink, plastic, and cosmetic sectors. The discharge of this coloring chemical into used water definitely generates a serious ecological issue

Objectives

Methods

Results

Conclusion