Kinetic Study of the Decolorization of Organic Dyes with Hydrogen Peroxide and TAML  Catalyst Melissa Medeiros and Dr. Chen-Lu Yang Advanced Technology and Manufacturing Center Kinetic Study of the Decolorization of Organic Dyes with Hydrogen Peroxide and TAML  Catalyst Melissa Medeiros and Dr. Chen-Lu Yang Advanced Technology and Manufacturing Center nColor can be removed using this method nDesign and Operation Parameters needed to engineer system for dye color removal: system for dye color removal:  2:1 molar ratio of H 2 O 2 with dye  2:1 molar ratio of H 2 O 2 with dye  20 µL TAML ® per 100 mL dye  20 µL TAML ® per 100 mL dye  Most efficient temp. = 40 °C  Most efficient temp. = 40 °C  Minimum Energy required to start  Minimum Energy required to start chemical reaction = 94.1 kJ / mol chemical reaction = 94.1 kJ / mol RB19 H 2 O 2 Conc. Variation Reactive Blue 19 (RB19) Dissociation reaction: H 2 O 2  HO H + H 2 O 2  HO H + Hydroxyl radical formation: (D: Donor) H 2 O 2 + D  D + + HO - + HO. H 2 O 2 + D  D + + HO - + HO. Perhydroxyl radical formation: H 2 O 2 + HO 2 -  HO 2. + HO - + HO. H 2 O 2 + HO 2 -  HO 2. + HO - + HO. Singlet oxygen formation: HO 2.  OH - + [O] HO 2.  OH - + [O] Fe 3+ + H 2 O 2  Fe +2 + H + + HO 2 Fe 3+ + H 2 O 2  Fe +2 + H + + HO 2. ntetra-amido macrocyclic ligand nAre catalysts formed from the elements C, H, N, O, and Fe nThe iron catalyst is a selective and efficient peroxide activator; it is also water soluble and effective in minuscule quantities. is also water soluble and effective in minuscule quantities. TAML ® nUnder the attack of oxidants, colorant chemical structures can be destroyed. structures can be destroyed.  breakup of conjugated double bonds  breakup of conjugated double bonds  cleavage of electron donors or  cleavage of electron donors or electron receptors electron receptors n Small molecules are produced n The end result is color removal Oxidation of Colorants RB19 TAML Conc. Variation RB19 Temperature Variation Plot of ln(1-x) Versus Time Arrhenius Plot Slope = -E a / R  R= X kJ mol -1 K -1 E a = 94.1 kJ / mol Procedures used in both the textile and paper industries are highly dependent on using vast quantities of water. Each year approximately 53 billion gallons of wastewater results from textile mills alone. The dye polluted wastewater is then released to treatment facilities or to surface waters. The current technologies employed to remove the dyes are expensive and high volumes of water are then needed to clear the dye from the wastewater treatment regions. Using hydrogen peroxide in conjunction with Fe-TAML catalyst removes increased amounts of dye from effluent and would allow manufacturers to recycle their waste water for reuse within their own facility. Introduction Reactions of H 2 O 2 The Role of Iron Before and After What Gives Dye Its Color? nChemically, there are two main structures: Azo and structures: Azo and Anthroquinone, shown above. Anthroquinone, shown above. - Conjugated double bonds -Chromophores: usually electron- receptors, unsaturated groups receptors, unsaturated groups -Auxochromes: usually electron- donors, saturated groups donors, saturated groups References Conclusions ® University of Massachusetts Dartmouth Chapter Sigma Xi Scientific Research Society 12 th UMASS Dartmouth Research Exhibition April 25 – 26, 2006