Dye Decolorization by Advanced Oxidation Process Using Locally Available Magnetite and Ilmenite by Khan Mamun Reza M. PHIL IN MATERIALS SCIENCE Department of Materials and Metallurgical Engineering BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY June, 2014 Declaration It is hereby declared that this thesis or any part of it has not been submitted elsewhere for the award of any degree or diploma. Khan Mamun Reza  iii Abstract Decolorization of Methylene Blue (MB) has been investigated using locally available magnetite and ilmenite under UV and solar light. Effects of catalyst dosage, dye concentration, concentration of H O , pH, and light intensity were observed. Impact of 2 2 inorganic salts and temperature on decolorization in presence of magnetite was also studied. Optimum value of catalyst and H O were found in case of Magnetite above which 2 2 decolorization decreases. Acidic condition (pH 3) was found to be preferable. All the inorganic anions except nitrate ions had negative impact on the decolorization. On the other hand higher catalyst dosage resulted in higher decolorization efficiency using Ilmenite. Optimum value was observed in case of H O . Lower acidic environment was found to be 2 2 preferable. The research also proved that high light intensity could improve the photocatalytic efficiency. 89% and 86% of .05 mM MB dye was removed for Magnetite and Ilmenite respectively in 30 minute reaction time.  iv Table of contents: 1: INTRODUCTION……………………………………………………………... 1 References…………………………………………………………………... 3 2: LITERATURE REVIEW…………………………………………………….. 6 2.1 Introduction………………………………………………………………… 6 2.2 Physical Methods…………………………………………………………… 6 2.2.1 Adsorption………………………………………………….. 6 2.2.2 Coagulation…………………………………………………. 8 2.2.3 Filtration…………………………………………………….. 8 2.3 Chemical Methods………………………………………………………….. 8 2.3.1 UV………………………………………………………….. 8 2.3.2 Sonication…………………………………………………... 9 2.3.3 O (Ozonation)……………………………………………… 10 3 2.3.4 O /ultrasonic………………………………………………… 11 3 2.3.5 O /UV………………………………………………………. 11 3 2.3.6 O /H O …………………………………………………….. 12 3 2 2 2.3.7 O /H O /UV………………………………………………... 12 3 2 2 2.3.8 Ozone/catalyst (O /CAT)…………………………………… 12 3 2.3.9 H O /US……………………………………………………. 12 2 2 2.3.10 H O /UV……………………………………………………. 12 2 2 2.3.11 TiO /UV…………………………………………………….. 13 2 2.3.12 Fenton process (Fe2+/H O system)………………………… 16 2 2 2.3.13 Photo-penton/ photo-fenton like process…………………… 16 References………………………………………………………………………….. 18 3. PHOTODECOMPOSITION OF METHYLENE BLUE BY MAGNETITE+H O +UV/SOLAR PROCESS……………………………… 30 2 2 3.1. Introduction………………………………………………………………… 30 3.2. Experimental………………………………………………………………... 31 3.2.1. Methylene blue dye…………………………………………. 31 3.2.2. Magnetite……………………………………………………. 32 3.2.3. Photocatalytic decomposition of MB……………………….. 33 3.2.4. Experimental setup………………………………………….. 35 3.3. Results and Discussion……………………………………………………… 36 3.3.1. Effect of magnetite dosage………………………………….. 37 3.3.2. Effect of oxidizing agent (H O )……………………………. 40 2 2 3.3.3. Effect of dye concentration………………………………….. 42 3.3.4. Effect of initial pH…………………………………………… 44 3.3.5. Effect of light………………………………………………... 46 3.3.6. Effect of temperature………………………………………... 47 3.3.7. Effect of inorganic anions…………………………………… 49 3.3.7.1. Effect of bicarbonate ion(cid:4666)(cid:1834)(cid:1829)(cid:1841)(cid:2879)(cid:4667)…………… 49 (cid:2871) 3.3.7.2. Effect of sulfite ion(cid:4666)SO(cid:2870)(cid:2879)(cid:4667)………………….. 50 (cid:2871)   v 3.3.7.3. Effect of sulfate ion(cid:4666)SO(cid:2870)(cid:2879)(cid:4667)…………………. 51 (cid:2872) 3.3.7.4. Effect of nitrate ion(cid:4666)NO(cid:2879)(cid:4667)…………………... 53 (cid:2871) 3.3.7.5. Effect of carbonate ion(cid:4666)(cid:1829)(cid:1841)(cid:2870)(cid:2879))………………. 54 (cid:2871) References…………………………………………………………………………… 55 4. PHOTODECOMPOSITION OF METHYLENE BLUE BY ILMENITE+H O +UV/SOLAR PROCESS…………………………………. 62 2 2 4.1. Introduction…………………………………………………………………. 62 4.2. Experimental………………………………………………………………… 62 4.2.1. Methylene blue dye………………………………………….. 62 4.2.2. Ilmenite………………………………………………………. 63 4.2.3. Photocatalytic decomposition of MB………………………... 64 4.2.4. Experimental setup…………………………………………... 65 4.3.Result and discussion………………………………………………………… 65 4.3.1. Ilmenite dosage………………………………………………………. 68 4.3.2. Effect of H O ...................................................................................... 70 2 2 4.3.3. Effect of dye concentration………………………………………….. 72 4.3.4. Effect of pH………………………………………………………….. 73 4.3.5. Effect of light intensity………………………………………………. 74 References……………………………………………………………………………. 75 5. CONCLUSION…………………………………………………………………. 78  vi List of Figures Fig. 3.1 Chemical formula of methylene blue. 31 Fig. 3.2 Absorption spectrum of methylene blue. 32 Fig. 3.3 XRD characterization of Magnetite 33 Fig. 3.4 Flow chart of the experimental procedure of Photo-decomposition of MB by Magnetite. 34 Fig. 3.5 Dye decolorization 34 Fig. 3.6 Schematic view of the experimental setup of the pohtodecomposition of MB using UV light source. 35 Fig. 3.7 Original setup. 35 Fig. 3.8 Cylindrical Pyrex cell of 250 cm3 with 100 cm3 of solution containing dye, Magnetite along with the magnetic bar. 36 Fig. 3.9 Experimental curve to understand the effect of different parameters. 37 Fig. 3.10 Influence of catalyst concentration on the degradation of MB. 38 Fig. 3.11 In (C /C) vs Time curve for different magnetite dosage. 39 O Fig. 3.12 Effect of the concentration of H O on the degradation of MB. 40 2 2 Fig. 3.13 Effect of the concentration of H O on the degradation rate constant of 2 2 MB. 41 Fig. 3.14 The effect of dye concentration on the photocatalytic decolorization of MB. 43 Fig. 3.15 The pseudo-first-order decolorization rate of MB at different dye concentration. 43 Fig. 3.16 Photocatalytic decolorization rate constants of MB at different pH. 44 Fig. 3.17 Effect of light source on the decolorization of MB. 46 Fig. 3.18 Effect of temperature on the decolorization of MB. 48 Fig. 3.19 Rate constant of the decolorization of MB at different temperature. 48 Fig. 3.20 The effect of bicarbonate ion on the photocatalytic decolorization rate constants of MB. 50 Fig. 3.21 The effect of Sulfite ion on the photocatalytic decolorization rate constants of MB. 51 Fig. 3.22 The effect of Sulfate ion on the photocatalytic decolorization rate constants of MB. 52 Fig. 3.23 The effect of Nitrate ion on the photocatalytic decolorization rate constants of MB. 53 Fig. 3.24 The effect of Carbonate ion on the photocatalytic decolorization rate constants of MB. 54 Fig. 4.1 Chemical formula and absorption spectrum of methylene blue. 63 Fig. 4.2 XRD characterization of Ilmenite. 63  vii Fig. 4.3 Flow chart of the experimental procedure of Photo-decomposition of MB 65 by Ilmenite. Fig. 4.4 Experimental curve to understand the effect of different processes of Ilmenite for dye degradation. 67 Fig. 4.5 Experimental curve to understand the effect of different parameters. 68 Fig. 4.6 Effect of catalyst concentration on the degradation of MB. 69 Fig. 4.7 Rate constant of MB for different dosage of Ilmenite. 69 Fig. 4.8 Effect of the concentration of H O on the degradation of MB. 71 2 2 Fig. 4.9 Effect of the concentration of H O on the degradation rate. 71 2 2 Fig. 4.10 The effect of dye concentration on the photocatalytic decolorization of MB. 72 Fig. 4.11 Decolorization rate with the increase of dye concentration. 72 Fig. 4.12 Effect of pH on the decolorization of MB. 73 Fig. 4.13 Effect of pH on the decolorization rate of MB. 74 Fig. 4.14 Effect of light intensity on decolorization of MB. 75  viii 1    1: INTRODUCTION Synthetic dyes are extensively used in many fields such as in textile industry [1, 2], in leather industry [2, 3], in paper production [1, 4], in food technology [5], in medical [6], in agricultural research [7, 8], in light-harvesting arrays [9], in potoelectrochemical cells [10], etc. At present, 100000 different types of dyes with annual production rate of 7×105 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 [11, 12, 13, 14]. Due to large-scale production and extensive application, synthetic dyes can cause considerable environmental pollution and are serious health-risk factors due to their stability and toxicity [15]. A wide range of methods has been developed for the removal of synthetic dyes from waters and wastewaters to decrease their impact on the environment. Conventional water treatment technologies such as solvent extraction, activated carbon adsorption, and chemical treatment process such as oxidation by ozone (O ) often produce hazardous by-products and generate large amount of solid wastes, which 3 require costly disposal or regeneration method [16, 17, 18]. Over the past few years, Advanced Oxidation Processes (AOP) has been proposed as alternative routes for water purification [17]. Even though AOP divided in to two categories (heterogeneous and homogenous catalysis), heterogeneous catalysis has been successfully employed for the degradation of various families of hazardous materials. Advanced Oxidation Processes (AOPs) are based on the generation of hydroxyl radical (•OH) which has high oxidation potential (2.8V) that completely converts organic contaminant into CO , H O and inorganic ions or biodegradable compounds [18, 19]. 2 2 •OH + dye → dye intermediate •OH + dye intermediate → CO + H O + inorganic ions or biodegradable compounds 2 2 Common AOPs involve Fenton, Fenton-like, photo-Fenton's processes, ozonation, photo chemical and electrochemical oxidation, photolysis with H O and O , high 2 2 3 voltage electrical discharge (corona) process, TiO photocatalysis, radiolysis, wet 2 oxidation, water solutions treatment by electronic beams or γ-beams and various combinations of these methods [20]. Compared with other oxidation processes, using Fenton type reagent are relatively cheap, easily operated and maintained [21]. Fenton process, one of the most effective processes for the removal of organic pollutants from aqueous solutions, involves the application of ferrous ions and hydrogen peroxide to produce hydroxyl radical. The photo-Fenton process combined Fenton process and light energy [22]. The most effective AOPs for treating dye solutions is a UV-enhanced H O /Fe2+ and H O /Fe3+ solutions [23]. 2 2 2 2 2    TiO has also been extensively investigated as a heterogeneous photocatalyst for the 2 remediation of contaminated environment [24]. Great attention has been devoted to the titanium dioxide (TiO ) due to its non-toxic, inexpensive, and high reactive nature [25]. The 2 advantage of TiO as photocatalyst is that the reactions do not suffer the drawbacks of 2 photolysis reactions in terms of the production of intermediate products because organic pollutants are usually completely mineralized to non-toxic substances such as CO , HCl 2 and water. Another benefit is that the reaction can take place at room temperature [26]. Magnetite (Fe O ) is a semimetal semiconductor with bandgap 0.14 eV. It contains both the 3 4 Fe2+ and Fe3+ 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 [27]. Madrakian et al. [28] 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. [29]. Ilmenite is a wide bandgap semiconductor with a measured band gap of about 2.5 eV [30]. As Ilmenite is crystalline iron titanium oxide (FeTiO ), it is expected that it will also show 3 excellent photocatalytic activity. Though in a previous experiment, Ilmenite shows high adsorption capacity for methylene blue [31]. Aim of Thesis: Operational problems and costs of various methods are the main unresolved problems in wastewater treatment. Optimizing the operational parameters is the main concern of the thesis. In this thesis Magnetite and Ilmenite collected from Cox’s Bazar sand are used as the catalyst. Characterization of the catalysts and the decolorization of the waste water with varying the different parameters are investigated in this work. Thesis Overview: The outline of this thesis is given as follows: Chapter 1: Overall introduction. Chapter 2: A review of the published literature related to wastewater treatment by different methods is discussed in this chapter. Chapter 3: In this chapter decolorization of Methylene Blue by Magnetite is studied. Dosage of Magnetite and H O , concentration of dye, intensity of light, pH, temperature 2 2 and inorganic ions are the parameters used to observe the rate of decolorization. 3    Chapter 4: Decolorization of Methlene Blue by Ilmenite is investigated in this chapter. Here dosage of Ilmenite and H O , concentration of dye and pH are the parameters used. 2 2 Chapter 5: Conclusion. References: [1] Vandevivere, P. C., Bianchi, R., Verstraete, W., “Treatment and Reuse of Wastewater from the Textile Wet-Processing Industry: Review of Emerging Technologies,” Journal of Chem. Technol. and Biotechnol., Vol. 72, pp. 289-302, 1998. [2] Sakthivel, S., Neppolian, B., Shankar, M. V., “Arabindoo B, Palanichamy M, Murugesan V. Solar photocatalytic degradation of azo dye:comparison of photocatalytic efficiency of ZnO and TiO ,” Sol. Energ. Mat. Sol. Cells., Vol. 77, 2 pp. 65-82, 2003. [3] Tunay, O., Kabdasli, I., Ohron, D., Cansever, G., “Use and minimization of water in leather tanning processes,” Water Sci. Technol., Vol. 40, pp. 237-244, 1999. [4] Ivanov, K., Gruber E., Schempp, W., Kirov, D., “Possibilities of using zeolite as filler and carrier for dye stuffs in paper,” Das Papier, Vol. 50, pp. 456-460, 1996. [5] Slampova, A., Smela, D., Vondrackova, A., Jancarova, I., Kuban, V., “Determination of synthetic colorants in foodstuffs,” Chemicke Listy, Vol. 95, pp. 163-168, 2001. [6] Haferlach, T., Bacher, U., Kern, W., Schnittger, S., Haferlach, C., “The diagnosis of BCR/ABL-negative chronic myeloproliferative diseases (CMPD): a comprehensive approach based on morphology, cytogenetics, and molecular markers,” Annals of Hematology, Vol. 87, pp. 1-10, 2008. [7] Cook, S. M. F., Linden, D. R., “Use of Rhodamine WT to facilitate dilution and analysis of atrazine samples in short-term transport studies,” Journal of Environmental Quality, Vol. 26, pp. 1438-1441, 1997. [8] Kross, B. C., Nicholson, H., F., Ogilvie, L. K., “Methods development study for measuring pesticide exposure to golf course workers using video imaging techniques,” Applied Occupational and Environmental Hygiene, Vol. 11, pp. 1346-1350, 1996. [9] Wagner, R., W., Lindsey, J., S., “Boron-dipyrromethane dyes for incorporation in synthetic multi-pigment light-harvesting arrays,” Pure and Applied Chemistry, Vol. 68, pp. 1373-1380, 1996. [10] Wrobel, D., Boguta, A., Ion, R. M., “Mixtures of synthetic organic dyes in a photoelectronic cell,” Journal of Photochemistry and Photobiology A: Chemistry, Vol. 138, pp. 7-22, 2001.