Abstract—The photocatalytic degradation of Methylene Blue (MB) dye has been investigated by locally available Magnetite with H 2 O 2 . Parameters such as Magnetite dosage, concentration of dye pH effect, light intensity and oxidizing agent (H 2 O 2 ) were used to study the degradation of MB. The degradation rates were found to be strongly influenced by all the above parameters. The Magnetite/ H 2 O 2 /UV process proved to be capable of decolorizing Methylene Blue. Index Terms—Photocatalytic degradation, magnetite, oxidizing agent, methylene blue. I. INTRODUCTION At present, 100000 different types of dyes with annual production rate of 7 × 10 5 tons are produced. Among them textile industries consume about 36000 ton/year dye. Up to 20% of the total world production of dyes is lost during the dyeing process and is released in the textile effluents [1], [2]. These synthetic dyes can cause considerable environmental pollution and are injurious to health due to their stability and toxicity. A wide range of physical methods has been developed for the removal of synthetic dyes. Conventional water treatment technologies such as physical methods mainly provide a phase transter of the contaminants from waste water to solid waste which require further treatments. On the other hand chemical oxidation methods include a family of processes that may be appropriate for treating dye pollutants. Advanced oxidation processes are promising technologies which aim at the decolorization and mineralization of a wide range of dyes and transform dyes into biodegradable or harmless products [3]. Photo-Fenton's oxidation is a homogeneous catalytic oxidation process using a mixture of hydrogen peroxide and ferrous ions. The addition of UV or artificial light to Fenton's process accelerate dye decolorization as it influences the direct formation of  OH radicals. The major reactions in the photo-fenton process for the formation of  OH radical include fenton reaction, photolysis of hydrogen peroxide and photoreduction of ferric ion, as shown in following equations respectively [4]. Fe 2+ + H 2 O 2 → • OH + Fe 3+ + OH − (1) Manuscript received March 29, 2015; revised June 25, 2015. Khan Mamun Reza is with the Department of Electronics and Communication Engineering, Faculty of Science and Engineering, Jatiya Kabi Kazi Nazrul Islam Univerisity, Trishal, Mymensingh, Bangladesh (e-mail: rezaape@yahoo.com ). Asw Kurny and Fahmida Gulshan are with the Department of Materials and Metallurgical Engineering, Faculty of Engineering, Bangladesh University of Engineering and Technology, Dhaka-1000, Bangladesh (e-mail: aswkurny@mme.buet.ac.bd, fahmidagulshan@mme.buet.ac.bd). H 2 O 2 + UV → 2OH • (2) Fe 3+ + UV+ H 2 O → • OH + Fe 2+ + H + (3) Magnetite (Fe 3 O 4 ) is a semimetal semiconductor with bandgap 0.14 eV. It contains both the Fe 2+ and Fe 3+ cations. So, it is expected that Magnitite will work as a photocatalyst. The possibility of using powder magnetite adsorption-Fenton oxidation as a method for removal of azo dye acid red B from water was studied by Rongcheng and Jiuhui [5]. Madrakian et al. [6] in their studies used magnetite nanoparticles- modified low-cost activated carbon (MMAC) as an adsorbent for the removal of the anionic and cationic dyes Congo red, reactive blue 19, thionine, janus green B, methylthymol blue and mordant Blue 29, from aqueous solutions. Utilization of magnetite nanoparticles modified with Cetyltrimethylammonium bromide (CTAB) for removal of Nyloset Yellow E-RK dye from water and waste water by magnetic force was also investigated by Dalali et al. [7]. The main objective of this study was to study the feasibility of Magnetite as a photocatalyst for decolorization of Methylene Blue dye. The influence of different operational parameters such as, Magnetite dosage, H 2 O 2 dosage, pH, dye concentration, temperature, light source and the presence of salt which affect the efficiency of Photo-Fenton's reaction was also investigated. II. EXPERIMENTAL A. Methylene Blue Dye Methylene Blue (MB) is one of the high consuming materials in the dye industry and was selected as a model organic pollutant and its degradation was studied in the presence of Magnetite under UV and solar illumination. Methylene blue (MB) is a cationic thiazine dye, basic in characteristic with the chemical name tetramethylthionine chloride. The chemical formula of MB (C 16 H 18 N 3 SCl) is shown in Fig. 1. It has a characteristic deep blue colour in the oxidized state; the reduced form (leukomethylene blue-LMB) is colorless. Maximum absorbance of MB is found at 664 nm. MB has widely been used in environmental sciences to study the suitability of various materials for wastewater discoloration [8]. Several key factors such as the dye concentration, concentration of oxidizing agent (H 2 O 2 ), light sources, pH and inorganic salts were investigated to provide a better knowledge of this photochemical reaction. Figure labels should be legible, approximately 8 to 12 point type. B. Magnetite Magnetite, used in our experiment was purchased from Beach Sand Materials Exploitation Centre (BSMEC). They Photocatalytic Degradation of Methylene Blue by Magnetite+H 2 O 2 +UV Process Khan M. Reza, Asw Kurny, and Fahmida Gulshan International Journal of Environmental Science and Development, Vol. 7, No. 5, May 2016 325 DOI: 10.7763/IJESD.2016.V7.793