Photodegradation Study of Toluidine Blue Dye in Aqueous Solution using Magnesium Oxide as a Photocatalyst

Haydar Mohammad Salim,Sabir Mohammad Salih

doi:10.5539/ijc.v7n2p143

Abstract

The photocatalytic degradation of Toluidine Blue dye (TB) in aqueous solution was investigated under UV light in the presence of magnesium oxide (MgO) as a photocatalyst at different operating parameters. The operating conditions were photocatalyst dose, initial dye concentration and the pH of the solution. Increasing of photocatalyst dose from 10 to 70 mg enhanced the degradation rate of TB dye. However, the increasing of TB dye concentration from 2 to 8 mg/L negatively affected the degradation rate. It was found that the percent of dye removal reached the maximum value at high acidic medium. In dark condition, 15 % of dye was adsorbed by MgO. Furthermore, the kinetics involved in the degradation of TB dye was examined and the degradation was found to follow pseudo first order kinetic model.

Highlights

Textile industries consume large amount of water and produce large volume of dye effluents, in deferent steps in the dyeing and finishing processes, which are non-biodegradable and toxic (Reife & Freeman, 1996)
The photocatalytic degradation of Toluidine Blue dye (TB) in aqueous solution was investigated under UV light in the presence of magnesium oxide (MgO) as a photocatalyst at different operating parameters
TiO2 and ZnO well known metal oxides for advanced oxidation processes (AOPs) and have higher band gap than MgO, ; MgO is less expensive and commercially available (Khan, Adil, & Al-Mayouf, 2015; Raza, Haque, Muneer, & Bahnemann).The aim of this study was to present the photocatalytic degradation of Toluidine Blue (TB) dye in aqueous solution using MgO as a photocatalyst under various operating conditions

Summary

Introduction

Textile industries consume large amount of water and produce large volume of dye effluents, in deferent steps in the dyeing and finishing processes, which are non-biodegradable and toxic (Reife & Freeman, 1996). Various physical and chemical processes such as reverse osmosis, adsorption, precipitation, ultrafiltration, flocculation and air stripping can be used for removal of colour from dye effluents (Georgiou, Melidis, Aivasidis, & Gimouhopoulos, 2002; Ledakowicz, Solecka, & Zylla, 2001; Peralta-Zamora et al, 1999; Robinson, McMullan, Marchant, & Nigam, 2001). These techniques, are non-destructive because they only transfer pollutants into sludge, which needs further treatment (Arslan, Balcioglu, Tuhkanen, & Bahnemann, 2000; Chaudhuri & Sur, 2000; Stock, Peller, Vinodgopal, & Kamat, 2000). Heterogeneous photocatalytic has emerged as a significant destructive technology leading to the total mineralization of most of the organic contaminants including organic dyes (Galindo, Jacques, & Kalt, 2001; Khodja, Sehili, Pilichowski, & Boule, 2001; Kusvuran, Samil, Atanur, & Erbatur, 2005; Neppolian, Choi, Sakthivel, Arabindoo, & Murugesan, 2002)

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