Preliminary study on optimization of pH, oxidant and catalyst dose for high COD content: solar parabolic trough collector
Tóm tắt
In the present study, solar photocatalytic oxidation has been investigated through laboratory experiments as an alternative to conventional secondary treatment for the organic content reduction of high COD wastewater. Experiments have been performed on synthetic high COD wastewater for solar photocatalytic oxidation using a parabolic trough reactor. Parameters affecting the oxidation of organics have been investigated. The experimental design followed the sequence of dark adsorption studies of organics, followed by photolytic studies (in absence of catalyst) and finally photocatalytic studies in presence and absence of additional oxidant (H2O2). All the experimental studies have been performed at pH values of 2, 4, 6,8,10 and the initial pH value of the wastewater (normal pH). For photocatalytic studies, TiO2 has been used as a photocatalyst. Optimization of catalyst dose, pH and H2O2 concentration has been done. Maximum reduction of organic content was observed at the normal pH value of the wastewater (pH = 6.8). The reaction rate was significantly enhanced in presence of hydrogen peroxide. The optimum pH other than the Normal was in the alkaline range. Acidic pH was not found to be favourable for organic content reduction. pH was found to be a dominant factor affecting reaction rate even in presence of H2O2 as an additional oxidant. Also, the solar detoxification process was effective in treating a waste with a COD level of more than 7500 mg/L, which is a otherwise a difficult waste to treat. It can therefore be used as a treatment step in the high organic wastewater treatment during the primary stage also as it effectively reduces the COD content by 86%.
Tài liệu tham khảo
Priya SS, Premalatha M, Anantharaman N: Solar photocatalyic treatment of phenolic wastewater potential, challenes and opportunities. ARPN J Eng Appl Sci. 2008, 3: 36-41.
Kositzi M, Poulios I, Malato S, Cáceres J, Campos A: Solar photocatalytic treatment of synthetic municipal wastewater. Water Res. 2004, 38: 1147-1154. 10.1016/j.watres.2003.11.024.
Shivaraju HP: Removal of Organic Pollutants in the Municipal Sewage Water by TiO2 based Heterogeneous Photocatalysis. Int J Environ Sci. 2011, 1: 911-923.
Chong MN, Jin B, Chow CWK, Saint C: Recent developments in photocatalytic water treatment technology: a review. Water Res. 2010, 44: 2997-3027. 10.1016/j.watres.2010.02.039.
Parilti NB: Treatment of a Petrochemical Industry Wastewater by a Solar Oxidation Process Using the Box-Wilson Experimental Design Method. Ekoloji. 2010, 19: 9-15. 10.5053/ekoloji.2010.772.
Inamdar J, Singh SK: Techno- Economic Analysis of Zero Effluent Discharge by Use of Solar Detoxification at Household Level. Int J Nat Sci Eng. 2008, 1: 208-211.
Balasaraswathy P: Paper presented in National Conference of Indian Association of Dermatology. 2004, Mumbai: Sunlight in India
Alpert DJ, Sprunga JL, Pachecoa JE, Prairiea MRH, Reillya E, Milneb TA, Nimlosb MR: Sandia national Laboratories’ work in solar detoxification of hazardous waste. Sol Energy Mat. 1991, 24: 594-607. 10.1016/0165-1633(91)90093-Z.
Babu GV, Sharat A, Nagaraju J: Solar decolorization of rhodamine B dye using concentrating collectors. J Sol Energy Soc India. 2002, 12: 73-80.
Nopens I, Capalozza C, Vanrolleghem PA: Stability analysis of a synthetic municipal wastewater, Department of Applied Mathematics, Biometrics and Process Control. 2001, 1-22.
Palmisano L, Augugliaro V, Compostrini R, Schiavello M: A proposal for the quantitative assessment of heterogeneous photocatalytic processes. J Cata. 1993, 143: 149-154. 10.1006/jcat.1993.1261.
Kabra K, Chaudhary R, Sawhney RL: Solar Photocatalytic Removal of Metal Ions from Industrial Wastewater. Int J Am Inst Chem Eng. 2008, 27: 487-495.
Muller TS, Sun Z, Kumar GMP, Itoh K, Murahayashi M: The combination of photocatalysis and ozonolysis as a new approach for cleaning 2,4, D polluted water. Chemosphere. 1998, 36: 2043-2055. 10.1016/S0045-6535(97)10089-3.
Emmanuel OA, Olalekan AMB: COD removal from industrial wastewater using activated carbon prepared from animal horns. Afr J Biotechnol. 2008, 7: 3887-3891.
Habibi MH, Vosooghian H: Photocatalytic degradation of some organic sulfides as environmental pollutants using titanium dioxide suspension. J Photochem Photobiol A: Chem. 2005, 174: 45-52. 10.1016/j.jphotochem.2005.02.012.
S-y Y, Y-y C, J-g Z, Y-j C: Enhanced photocatalytic activity of TiO2 by surface fluorination in degradation of organic cationic compound. J Environ Sci. 2007, 19: 86-89. 10.1016/S1001-0742(07)60014-X.
Akpan UG, Hameed BH: Parameters affecting the photocatalytic degradation of dyes using TiO2-based photocatalysts: a review. J Hazard Mater. 2009, 170: 520-529. 10.1016/j.jhazmat.2009.05.039.
Diya’uddeen BH, Wan Mohd Ashri Wan D, Abdul Aziz AR: Treatment technologies for petroleum refinery effluents: A review. Process Saf Environ Prot. 2011, 8: 95-105.
Chakrabarti S, Dutta B: Photocatalytic degradation of model textile dyes in wastewater using ZnO as semiconductor catalyst. J Hazard Mater. 2004, B112: 269-278.
Konstantinou I, Albanis T: TiO2-assisted photo catalytic degradation of azo dyes in aqueous solution: kinetic and mechanistic investigations — a review. Appl Catal B: Environ. 2004, 49: 1-14. 10.1016/j.apcatb.2003.11.010.
Ehrampoush MH, Moussavi GHR, Ghaneian MT, Rahimi S, Ahmadian M: Removal Of Methylene Blue Dye From Textile Simulated Sample Using Tubular Reactor And TiO2/UV-C Photocatalytic Process. Iran J Environ Health Sci Eng. 2011, 8: 35-40.
Rajeswari R, Kanmani S: TiO2-Based Heterogeneous Photocatalytic Treatment Combined With Ozonation For Carbendazim Degradation. Iran J Environ Health Sci Eng. 2009, 6: 61-66.
Poulios I, Tsachpinis I: Photodegradation of the textile dye Reactive Black 5 in the presence of semiconducting oxides. J Chem Technol Biotechnol. 1999, 74: 349-357. 10.1002/(SICI)1097-4660(199904)74:4<349::AID-JCTB5>3.0.CO;2-7.
Coelho A, Castro AV, Dezotti M, SantAnna GL: Treatment of petroleum refinery sour water by advanced oxidation processes. J Hazard Mater. 2006, 137: 178-184. 10.1016/j.jhazmat.2006.01.051.
Li Y, Yan L, Xiang C, Hong LJ: Treatment of oily wastewater by organic–inorganic composite tubular ultrafiltration (UF) membranes. Desalination. 2006, 196: 76-83. 10.1016/j.desal.2005.11.021.
Parvin T, Keerthiraj N, Ibrahim IA, Phanichphant S, Byrappa K: Photocatalytic Degradation of Municipal Wastewater and Brilliant Blue Dye Using Hydrothermally Synthesized Surface-Modified Silver-Doped ZnO Designer Particles. Int J Photoenergy. 2012, 2012: 1-8.
Cornu JG: Photocatalysis under periodic illumination. Ph.D. thesis. 2002, California: California institute of technology Pasadena
Antoine L, Corinne F, Jean MC, Jean MH: Naphthalene degradation in water by heterogeneous photocatalysis: An investigation of the influence of inorganic anions. J Photochem Photobiol A: Chemistry. 2008, 193: 193-203. 10.1016/j.jphotochem.2007.06.025.
Herrmann JM: Heterogeneous photocatalysis: fundamentals and applications to the removal of various types of aqueous pollutants. Catal Today. 1999, 53: 115-129. 10.1016/S0920-5861(99)00107-8.
Ichimura T, Matsushita Y, Sakeda K, Suzuki T: Photoreactions. Microchemical Engineering in Practice. Edited by: Dietrich TR. 2009, New Jersey: Wiley-Blackwell, John Wiley and Sons, Inc, 487-488.
Cardona SPP: Coupling of photocatalytic and biological processes as a contribution to the detoxification of water: catalytic and technological aspects, Thesis no 2470. 2001, Lausanne: EPFL