A Study on the Degradation of Carbamazepine and Ibuprofen by TiO₂ & ZnO Photocatalysis upon UV/Visible-Light Irradiation

Irene Georgaki, Eva Vasilaki, Nikos Katsarakis

Center of Materials Technology and Photonics, School of Applied Technology, Technological Educational Institute of Crete, Heraklion, Greece.
Institute of Electronic Structure and Laser, Foundation for Research & Technology-Hellas, Heraklion, Greece.

DOI: 10.4236/ajac.2014.58060                

Abstract

The degradation of carbamazepine (CBZ) and ibuprofen (IBP) in aqueous matrices was investigated by TiO₂ and ZnO photocatalysis initiated by UV-A and visible-light irradiation. Emphasis was given on the effect of operating parameters on the degradation effectiveness, such as catalyst type and loading (50 - 500 mg/L), initial drug concentration (10, 40, 80 mg/L) and wavelength of irradiation (200 - 600 nm). In an effort to understand the photocatalytic pathway for CBZ and IBP removal in terms of primary oxidants, the contribution of HO· was evaluated. With this scope, the radical-mediated process was suppressed by addition of an alcohol scavenger, isopropanol, (i-PrOH), described as the best free hydroxyl radical quencher. The photodegradation rate of the pharmaceuticals was monitored by high performance liquid chromatography (HPLC). According to the results, visible-light exposure, at λ_exc > 390 nm, takes place as a pure photocatalytic degradation reaction for both compounds. IBP was found to have overall high conversion rates, compared to CBZ. IBP oxidized fast under photocatalytic conditions, regardless the adverse effect of the increase of initial drug concentration, or low catalyst load, irradiation upon visible-light, by either titania or zinc oxide. Finally, addition of isopropanol showed a significant inhibition effect on the CBZ degradation, taken as an evidence of a solution-phase mechanism. In the case though of IBP degradation, the hole mechanism may be prevailing, suggested by the negligible effect upon addition of isopropanol indicating a direct electron transfer between holes (h⁺) and surface-bound IBP molecules. A plausible mechanism of IBP and CBZ photocatalysis was proposed and described.

Keywords

Photodegradation, Carbamazepine, Ibuprofen, Titania Photocatalysis, Zinc Oxide Photocatalysis, Oxidation Pathway

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Madhavan, J., Grieser, F. and Ashokkumar, M. (2010) Combined Advanced Oxidation Processes for the Synergistic Degradation of Ibuprofen In Aqueous Environments. Journal of Hazardous Materials, 178, 202-208. http://dx.doi.org/10.1016/j.jhazmat.2010.01.064
[2]	Daughton, C. and Ternes, T.A. (1999) Pharmaceuticals and Personal Care Products in the Environment: Agents of Subtle Change? Environmental Health Perspectives, 107, 907-938. http://dx.doi.org/10.1289/ehp.99107s6907
[3]	Doll, T.E. and Frimmel, F.H. (2003) Fate of Pharmaceuticals-Photodegradation by Simulated Solar-UV Light. Chemosphere, 52, 1757-1769. http://dx.doi.org/10.1016/S0045-6535(03)00446-6
[4]	Ternes, T.A. (1998) Occurrence of Drugs in German Sewage Treatment Plants and Rivers. Water Research, 32, 3245-3260. http://dx.doi.org/10.1016/S0043-1354(98)00099-2
[5]	Putschew, A., Wischnack, S. and Jekel, M. (2000) Occurrence of Triiodinated X-Ray Contrast Agents in the Aquatic Environment. Science of the Total Environment, 255, 129-134. http://dx.doi.org/10.1016/S0048-9697(00)00461-7
[6]	Sacher, F., Lange, F.T., Brauch, H.J. and Blankenhorn, I. (2001) Pharmaceuticals in Groundwaters Analytical Methods and Results of a Monitoring Program in Baden-Württemberg, Germany. Journal of Chromatography A, 938, 199-210. http://dx.doi.org/10.1016/S0021-9673(01)01266-3
[7]	Anderson, P.D., D’Aco, V.J., Shanahan, P., Chapra, S.C., Buzby, M.E., Cunningham, V.L., Duplessie, B.M., Hayes, E.P., Mastracco, F.J., Parke, N.J., Rader, J.C., Samuelian, J.H. and Schwab, B.W. (2004) Screening Analysis of Human Pharmaceutical Compounds in US Surface Waters. Environmental Science Technology, 38, 838-859. http://dx.doi.org/10.1021/es034430b
[8]	Heberer, T., Dünnbier, U., Reilich, C. and Stan, H.J. (1997) Detection of Drugs and Drug Metabolites in Groundwater Samples of Drinking Water Treatment Plant. Fresenius Environmental Bulletin, 6, 438-443.
[9]	Heberer, T. (2002) Tracking Persistent Pharmaceutical Residues from Municipal Sewage to Drinking Water. Journal of Hydrology, 266, 175-189. http://dx.doi.org/10.1016/S0022-1694(02)00165-8
[10]	Carballa, M., Omil, F., Lema, J., Llompart, M., Gar-cía-Jares, C., Rodríguez, I., Gómez, M. and Ternes, T. (2004) Behavior of Pharmaceuticals, Cosmetics and Hormones in a Sewage Treatment Plants. Water Research, 38, 2918-2926. http://dx.doi.org/10.1016/j.watres.2004.03.029
[11]	Andreozzi, R., Rafaele, M. and Paxeus, N. (2003) Pharmaceuticals in STP Effluents and Their Solar Photodegradation in Aquatic Environment. Chemosphere, 50, 1319-1330. http://dx.doi.org/10.1016/S0045-6535(02)00769-5
[12]	Kosma, C.I., Lambropoulou, D.A., Albanis, T.A. (2010) Occurrence and Removal of PPCPs in Municipal and Hospital Wastewaters in Greece. Journal of Hazardous Materials, 179, 804-817. http://dx.doi.org/10.1016/j.jhazmat.2010.03.075
[13]	Dorne, J.L.C.M., Skinner, L., Frampton, G.K., Spurgeon, D.J. and Ragas, A.M.J. (2007) Human and Environmental Risk Assessment of Pharmaceuticals: Differences, Similarities, Lessons from Toxicology. Analytical and Bioanalytical Chemistry, 387, 1259-1268. http://dx.doi.org/10.1007/s00216-006-0963-7
[14]	Pomati, F., Netting, A.G., Calamari, D., Neilan, B.A. (2004) Effects of Erythromycin, Tetracycline And Ibuprofen on the Growth of Synechocystis sp. and Lemna minor. Aquatic Toxicology, 67, 387-396. http://dx.doi.org/10.1016/j.aquatox.2004.02.001
[15]	Ferrari, B., Paxeus, N., Lo Giudice, R., Pollio, A. and Garric, J. (2003) Ecotoxicological Impact of Pharmaceuticals Found in Treated Wastewaters: Study of Carbamazepine, Clofibric Acid, and Diclofenac. Ecotoxicology and Environmental Safety, 55, 359-370. http://dx.doi.org/10.1016/S0147-6513(02)00082-9
[16]	Achilleos, A., Hapeshi, E., Xekoukoulotakis, N.P., Mantzavinos, D. and Fatta-Kassinos, D. (2010) UV-A and Solar Photodegradation of Ibuprofen and Carbamazepine Catalyzed by TiO2. Separation Science and Technology, 45, 1564-1570. http://dx.doi.org/10.1080/01496395.2010.487463
[17]	Cleuvers, M. (2004) Mixture Toxicity of the Anti-Inflammatory Drugs Diclofenac, Ibuprofen, Naproxen, and Acetylsalicylic Acid. Ecotoxicology and Environmental Safety, 59, 309-315. http://dx.doi.org/10.1016/S0147-6513(03)00141-6
[18]	Fent, K., Weston, A. and Caminada, D. (2006) Ecotoxicology of Human Pharmaceuticals. Aquatic Toxicology, 76, 122-159. http://dx.doi.org/10.1016/j.aquatox.2005.09.009
[19]	Prakash Reddy, N.C., Anjaneyulu, Y., Sivasankari, B. and Ananda Rao, K. (2006) Comparative Toxic Studies in Birds Using Nimesulide and Diclofenac Sodium. Environmental Toxicology and Pharmacology, 22, 142-147. http://dx.doi.org/10.1016/j.etap.2006.02.004
[20]	Martínez, C., Canle, L.M., Fernández, M.I., Santaballa, J.A. and Faria, J. (2011) Kinetics and Mechanism of Aqueous Degradation of Carbamazepine by Heterogeneous Photocatalysis Using Nanocrystalline TiO2, ZnO and Multi-Walled Carbon Nanotubes—Anatase Composites. Applied Catalysis B: Environmental, 102, 563-571. http://dx.doi.org/10.1016/j.apcatb.2010.12.039
[21]	Kolpin, D.W., Furlong, E.T., Meyer, M.T., Thurman, E.M., Zaugg, S.D., Barber, L.B. and Buxton, H.T. (2002) Pharmaceuticals, Hormones, and Other Organic Wastewater Contaminants in U.S. Streams, 1999-2000: A National Reconnaissance. Environmental Science & Technology, 36, 1202-1211. http://dx.doi.org/10.1021/es011055j
[22]	Castiglioni, S., Bagnati, R., Fanelli, R., Pomati, F., Calamari, D. and Zuccato, E. (2006) Removal of Pharmaceuticals in Sewage Treatment Plants in Italy. Environmental Science & Technology, 40, 357-363. http://dx.doi.org/10.1021/es050991m
[23]	Rizzo, L., Meric, S., Guida, M., Kassinos, D. and Belgiorno, V. (2009) Heterogeneous Photocatalytic Degradation Kinetics and Detoxification of an Urban Wastewater Treatment Plant Effluent Contaminated with Pharmaceuticals. Water Research, 43, 4070-4078. http://dx.doi.org/10.1016/j.watres.2009.06.046
[24]	Méndez-Arriaga, F., Esplugas, S. and Giménez, J. (2008) Photocatalytic Degradation of Nonsteroidal Anti-Inflammatory Drugs with TiO2 and Simulated Solar Irradiation. Water Research, 42, 585-594. http://dx.doi.org/10.1016/j.watres.2007.08.002
[25]	Doll, T.E. and Frimmel, F.H. (2005) Removal of Selected Persistent Organic Pollutants by Heterogeneous Photocatalysis in Water. Catalysis Today, 101, 195-202. http://dx.doi.org/10.1016/j.cattod.2005.03.005
[26]	Canle, L.M., Santaballa, J.A. and Vulliet, E. (2005) On the Mechanism of TiO2-Photocatalyzed Degradation of Aniline Derivatives. Journal of Photochemistry and Photobiology A: Chemistry, 175, 192-200. http://dx.doi.org/10.1016/j.jphotochem.2005.05.001
[27]	Sun, Y. and Pignatello, J.J. (1995) Evidence for a Surface Dual Hole-Radical Mechanism in the Titanium Dioxide Photocatalytic Oxidation of 2,4-D. Environmental Science & Technology, 29, 2065-2072. http://dx.doi.org/10.1021/es00008a028
[28]	Rabani, J., Yamashita, K., Ushida, K., Stark, J. and Kira, A. (1998) Fundamental Reactions in Illuminated Titanium Dioxide Nanocrystallite Layers Studied by Pulsed Laser. Journal of Physical Chemistry B, 102, 1689-1695. http://dx.doi.org/10.1021/jp973411j
[29]	Lawless, D., Serpone, N. and Meisel, D. (1991) Role of Hydroxyl Radicals and Trapped Holes in Photocatalysis. A Pulse Radiolysis Study. Journal of Physical Chemistry, 95, 5166-5170. http://dx.doi.org/10.1021/j100166a047
[30]	Turchi, C.S. and Ollis, D.E. (1990) Photocatalytic Degradation of Organic Water Contaminants: Mechanisms Involving Hydroxyl Radical Attack. Journal of Catalysis, 122, 178-192. http://dx.doi.org/10.1016/0021-9517(90)90269-P
[31]	Okamoto, K.I., Yamamoto, Y., Tanaka, H., Tanaka, M. and Itaya, A. (1985) Heterogeneous Photocatalytic Decomposition of Phenol over TiO2 Powder. Bulletin of the Chemical Society of Japan, 58, 2015-2022. http://dx.doi.org/10.1246/bcsj.58.2015
[32]	Sakthivel, S., Neppolian, B., Shankar, M.V., Arabindoo, B., Palanichamy, M. and Murugesan, V. (2003) Solar Photo-catalytic Degradation of Azo Dye: Comparison of Photocatalytic Efficiency of ZnO and TiO2. Solar Energy Materials and Solar Cells, 77, 65-82. http://dx.doi.org/10.1016/S0927-0248(02)00255-6
[33]	Houas, A., Lachheb, H., Ksibi, M., Elaloui, E., Guillard, C. and Herrmann, J. (2001) Photocatalytic Degradation Pathway of Methylene Blue in Water. Applied Catalysis B: Environmental, 31, 145-157. http://dx.doi.org/10.1016/S0926-3373(00)00276-9
[34]	Chen, Y.X., Yang, S.Y., Wang, K. and Lou, L.P. (2005) Role of Primary Active Species and TiO2 Surface Characteristic in UV Illuminated Photodegradation of Acid Orange 7. Journal of Photochemistry and Photobiology A: Chemistry, 172, 47-54. http://dx.doi.org/10.1016/j.jphotochem.2004.11.006
[35]	Ilisz, I. and Dombi, A. (1999) Investigation of the Photodecomposition of Phenol in near-UV-Irradiated Aqueous TiO2 Suspensions. II. Effect of Charge-Trapping Species on Product Distribution. Applied Catalysis A: General, 180, 35-45. http://dx.doi.org/10.1016/S0926-860X(98)00375-5
[36]	Park, H. and Choi, W. (2004) Effects of TiO2 Surface Fluorination on Photocatalytic Reactions and Photoelectrochemical Behaviors. Journal of Physical Chemistry B, 108, 4086-4093. http://dx.doi.org/10.1021/jp036735i
[37]	El-Morsi, T.M., Budakowski, W.R., Abd-El-Aziz, A.S. and Friesen, K.J. (2000) Photocatalytic Degradation of 1,10-Dichlorodecane in Aqueous Suspensions of TiO2: A Reaction of Adsorbed Chlorinated Alkane with Surface Hydroxyl Radicals. Environmental Science & Technology, 34, 1018-1022. http://dx.doi.org/10.1021/es9907360
[38]	Calza, P. and Pelizzetti, E. (2001) Photocatalytic Transformation of Organic Compounds in the Presence of Inorganic Ions. Pure and Applied Chemistry, 73, 1839-1848. http://dx.doi.org/10.1351/pac200173121839
[39]	Minero, C., Mariella, G., Maurino, V. and Pelizzetti, E. (2000) Photocatalytic Transformation of Organic Compounds in the Presence of Inorganic Anions. 1. Hydroxyl-Mediated and Direct Electron-Transfer Reactions of Phenol on a Titanium Dioxide-Fluoride System. Langmuir, 16, 2632-2641. http://dx.doi.org/10.1021/la9903301
[40]	Tunesi, S. and Anderson, M. (1991) Influence of Chemisorption on the Photodecomposition of Salicylic Acid and Related Compounds Using Suspended Titania Ceramic Membranes. Journal of Physical Chemistry, 95, 3399-3405. http://dx.doi.org/10.1021/j100161a078
[41]	Camacho-Munoz, D., Martin, J., Santos, J., Aparicio, I. and Alonso, E. (2009) An Affordable Method for the Simultaneous Determination of the Most Studied Pharmaceutical Compounds as Wastewater and Surface Water Pollutants. Journal of Separation Science, 32, 3064-3073. http://dx.doi.org/10.1002/jssc.200900128
[42]	Lin, Y., Ferronato, C., Deng, N., Wu, F. and Chovelon, J.M. (2009) Photocatalytic Degradation of Methylparaben by TiO2: Multivariable Experimental Design and Mechanism. Applied Catalysis B: Environmental, 88, 32-41. http://dx.doi.org/10.1016/j.apcatb.2008.09.026
[43]	Neppolian, B., Choi, H.C., Sakthivel, S., Arabindoo, B. and Murugesan, V. (2002) Solar/UV-Induced Photocatalytic Degradation of Three Commercial Textile Dyes. Journal of Hazardous Materials, 89, 303-317. http://dx.doi.org/10.1016/S0304-3894(01)00329-6
[44]	Molinary, R., Pirrilo, F., Loddo, V. and Palmisano, L. (2006) Heterogeneous Photocatalytic Degradation of Pharmaceuticals in Water by Using Polycrystalline TiO2 and a Nanofiltration Membrane Reactor. Catalysis Today, 118, 205-213. http://dx.doi.org/10.1016/j.cattod.2005.11.091
[45]	Ohno, T., Sarukawa, K., Tokieda, K. and Matsumura, M. (2001) Morphology of a TiO2 Photocatalyst (Degussa, P-25) Consisting of Anatase and Rutile Crystalline Phases. Journal of Catalysis, 203, 82-86. http://dx.doi.org/10.1006/jcat.2001.3316
[46]	Miyagi, T., Kamei, M., Mitsuhashi, T., Ishigaki, T. and Yamazaki, A. (2004) Charge Separation at the Rutile/Anatase Interface: A Dominant Factor of Photocatalytic Activity. Chemical Physics Letters, 390, 399-402. http://dx.doi.org/10.1016/j.cplett.2004.04.042
[47]	Bickley, R., Gonzalez-Carreno, T., Lees, J., Palmisano, L. and Tilleys, R.J. (1991) A Structural Investigation of Titanium Dioxide Photocatalysts. Journal of Solid State Chemistry, 92, 178-190. http://dx.doi.org/10.1016/0022-4596(91)90255-G
[48]	Daneshvar, N., Salari, D. and Khataee, A.R. (2004) Photocatalytic Degradation of Azo Dye Acid Red 14 in Water on ZnO as an Alternative Catalyst to TiO2. Journal of Photochemistry and Photobiology A: Chemistry, 162, 317-322. http://dx.doi.org/10.1016/S1010-6030(03)00378-2