Wet Oxidation of Bisphenol A by Metal Supported SBA-15 Bull. Korean Chem. Soc. 2014, Vol. 35, No. 12 3535 http://dx.doi.org/10.5012/bkcs.2014.35.12.3535 SBA-15 Supported Fe, Ni, Fe-Ni Bimetallic Catalysts for Wet Oxidation of Bisphenol-A Suranjana V. Mayani, Vishal J. Mayani, and Sang Wook Kim * Department of Advanced Materials Chemistry, College of Science and Technology, Dongguk University, Gyeongbuk 780-714, Korea. * E-mail: swkim@dongguk.ac.kr Received July 23, 2014, Accepted August 18, 2014 Bisphenol A is considered as pollutant, because it is toxic and hazardous to living organisms even at very low concentrations. Biological oxidation used for removing this organic from waste water is not suitable and consequently application of catalytic wet oxidation has been considered as one of the best options for treating bisphenol A. We have developed Fe/SBA-15, Ni/SBA-15 and Fe-Ni/SBA-15 as heterogeneous catalysts using the advanced impregnation method for oxidation of bisphenol A in water. The catalysts were characterized with physico-chemical characterization methods such as, powder X-ray diffraction (PXRD), FT-IR measurements, N 2 adsorption–desorption isotherm, thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectroscopy (ICP- OES) analysis. This work illustrates activity of the catalysts for heterogeneous catalytic degradation reaction revealed with excellent conversion and recyclability. The degradation products identified were not persistent pollutants. GC-MS analysis identified the products: 2,4-hexadienedioic acid, 2,4-pentadienic acid and isopropanol or acetic acid. The leachability study indicated that the catalysts release very little metals to water. Therefore, the possibility of water contamination through metal leaching was almost negligible. Key Words : Bisphenol A, Catalytic degradation, Heterogeneous catalysts, Leachability study, Wet oxidation Introduction Bisphenol A (BPA) has received great attention as an intermediate chemical in the manufacturing of polycarbon- ate plastic, epoxy resin, polyester-styrene resins. 1,2 BPA is manufactured in high quantities, for production of powder paints, adhesives, building materials, compact disks, thermal paper and paper coatings. Due to the daily use of these pro- ducts, high concentrations of BPA are observed in waste- water. During the manufacturing process, some BPA can be unintentionally released into the environment. BPA has biological toxicity 3 and estrogenic activity 4 toward aquatic organisms and human cultured cells. BPA is considered as pollutant, because it is toxic and hazardous to living organisms, even at very low concentrations.Therefore, it is necessary to develop efficient treatment methodology for the removal of BPA in wastewater. Wastewater treatment methods like chemical precipitation, activated carbon adsorption and ion exchange are typically useful in the removal of bisphenol A. 5-7 But, they transfer the contaminants from one medium to another and hence further treatment is required. Hence, a rapid, simple and economic wastewater treatment for the removal of BPA is now highly in demand. The conventional pollutant destructive technologies include biological, thermal and physico-chemical treatments. 8 Bio- logical treatments normally require a long time for micro- organisms to degrade the pollutant because they are affected by bisphenol A toxicity, thermal treatments produce con- siderable emissions of other harmful compounds and physico- chemical techniques, such as flocculation, precipitation, adsorption on activated carbon and reverse osmosis, require a post treatment to remove the pollutant from a newly polluted environment. 9 Alternative methods to these well established techniques are advanced oxidation processes, 10 which have been reported to be useful for the near ambient degradation of soluble organic contaminants from water and soil providing almost total degradation. Mesoporous materials (SBA-15, MCM-41 etc) have attracted considerable attention in the field of catalysis and adsorption owing to their characteristic properties such as, high surface area, large pore volume, regular structure, uniform pore size distribution and relatively high thermal stability. 11-14 SBA-15 has better mechanical and hydrothermal stability than MCM-41. 12 On the other hand, it is very diffi- cult to introduce other metal ions directly into the SBA-15 framework because of the strong acidic conditions for SBA- 15 synthesis. 12,15 Recently, several researchers reported the incorporation of hetero atoms, such as Al, Fe, Co, Ni, Cr and Ti, into the framework of SBA-15 by modifying the pH and/ or the hydrothermal method of preparation. 16-19 Fe 2 O 3 /SBA- 15 nano composites, titania-deposited SBA-15, crystalline iron oxide supported on meso-structured SBA-15 materials, Fe/SBA-15 have been applied to waste water treatment processes. 20-23 The use of a solid catalyst offers the further advantages of easy recovery, regeneration and reuse, com- pared to a homogeneous catalyst. 24 In the present work, bisphenol A (BPA) is adopted as a model compound to evaluate the wet catalytic oxidation by transition metal supported catalysts (Fe/SBA-15, Ni/SBA- 15 and Fe-Ni/SBA-15). The effects of reaction time, temper-