5-1 Conclusions
This study demonstrated that ozonation process can be an effective method to remove diclofenac from water. At variable pH condition, diclofenac as well as TOC were degraded very quickly by ozonation. The inorganic by-products, e.g., chloride, reached to a maximum concentration rapidly under high ozone dose. On the contrary, the effect of ozone dose on TOC removal was insignificant, and the extent of chloride formation decreased significantly with a low ozone dose, which implied that ozone dose played an important role on the degradation and mineralization of diclofenac.
At fixed pH condition, i.e., controlled by adding phosphate buffer, the diclofenac degradation was slower. In addition, phosphate buffer also enhanced the extent of TOC degradation as ozone dose increased. The amount of chloride formation decreased as the phosphate buffer was added, but the formation of ammonia was insignificantly affected by adding phosphate buffer. In summary, the most effective condition for TOC degradation was determined at pH of 7.4..
The formation rates of CO2, chloride and ammonia were calculated to determine based on the mass balance to determine the corresponding rate constant. The rate constant for carbon dioxide formation increased as pH increased from 5.5 to 7.4, and then decreased as pH from 7.4 to 8.9. The rate constant for chloride formation was in the same pattern as carbon dioxide formation. The rate constant for ammonia formation increased as pH increased at a lower ozone dose, whereas it decreased then increased at a higher ozone dose.
The kinetic constant, derived from the assumption of pseudo-first order reaction, increased as the pH increased, which followed the same pattern as carbon and chloride formations. In the kinetic model, the selectivity of chloride releasing and
5- 2
ammonia releasing were 0.35 and 0.13, respectively. From the results, it can be concluded that ozonation of diclofenac tended to favor the oxidation of chloride ions than C-N bond cleavage.
The ozone attacked the amino group and aromatic ring of diclofenac and resulted in generating ozonation by-products such as aldahydes. In this study, the formation of aldehyde increased with increasing pH. Regarding to human health, the lowest carcinogenetic risk was determined based on the lowest formation concentration of aldehyde at ozone dosage of 20 mg/L and pH 5.5 through the health assessment proposed by USEPA. Coupling the health risk assessment with the result of rate constant calculation, ozone dose of 60 mg/L and pH 7.4 would be considered as the optimum operation condition in term of reducing diclofenac, CO2 formation rate, and carcinogenetic risk.
5-2 Recommendations
1 The formation of intermediates and the pathway for diclofenac degradation are still not well developed. It is suggested that further experiments be focused on the formation of intermediates as well as the pathway of degradation.
2 Besides aldehydes, carcinogenetic risk of other ozonation by-products should be further investigated to make the health risk assessment more comprehensive.
3 The input variables for executing ANOVA and RSM analyses should be more complete for optimizing the process in reducing diclofenac.
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Reference
Angela Y-C Lin, Tsai, Y-T., 2009. Occurrence of pharmaceuticals in Taiwan's surface waters: Impact of waste streams from hospitals and pharmaceutical production facilities. Sci Total Environ 407, 3793-3802
Akmehmet BalcIoglu, I., Ö tker, M., 2003. Treatment of pharmaceutical wastewater containing antibiotics by O3 and O3/H2O2 processes. Chemosphere 50, 85-95.
Andreozzi, R., Caprio, V., Marotta, R., Radovnikovic, A., 2003. Ozonation and H2O2/UV treatment of clofibric acid in water: a kinetic investigation. Journal of Hazardous Materials 103, 233-246.
Araujo, L., Wild, J., Villa, N., Camargo, N., Cubillan, D., Prieto, A., 2008.
Determination of anti-inflammatory drugs in water samples, by in situ derivatization, solid phase microextraction and gas chromatography-mass spectrometry. Talanta 75, 111-115.
Bartels and W. Von Tümpling, 2007. Solar radiation influence on the decomposition process of diclofenac in surface waters. Sci Total Environ 374 , 143–155.
Buser H-R, Poiger T., Muller M. D., 1998. Occurrence and fate of the pharmaceutical drug diclofenac in surface waters: Rapid phtodegradation in a lake. Environ Sci Technol 32, 3449-3456
Beno, icaron, Ferrari, t., Mons, R., Vollat, B., Fraysse, t., Pax, N., emacr, aus, Giudice, R.L., Pollio, A., Garric, J., 2004. Environmental risk assessment of six human pharmaceuticals: Are the current environmental risk assessment procedures sufficient for the protection of the aquatic environment. Environmental Toxicology and Chemistry 23, 1344-1354.
Beltrán, F.J., Aguinaco, A., García-Araya, J.F., Oropesa, A., 2008. Ozone and
R- 2
photocatalytic processes to remove the antibiotic sulfamethoxazole from water.
Water Research 42, 3799-3808.
Calza, V.A. Sacas, C. Medana, C. Baiocchi, A. Dimos and E. Pelizzetti et al., 2006.
Photocatalytic degradation study of diclofenac over aqueous TiO2 suspensions. Appl Catal B-Environ 67, 197–205.
Canosa, P., Rodriguez, I., Rubí, E., Cela, R., 2005. Optimization of solid-phase microextraction conditions for the determination of triclosan and possible related compounds in water samples. Journal of Chromatography A 1072, 107-115.
Carpinteiro, J., Quintana, J.B., MartInez, E., RodrIguez, I., Carro, A.M., Lorenzo, R.A., Cela, R., 2004. Application of strategic sample composition to the screening of anti-inflammatory drugs in water samples using solid-phase microextraction. Analytica Chimica Acta 524, 63-71.
Chang, E.E., Chiang, P.C., Li, I.S., 2007. Reduction of low-MW model compounds by ozonation and O3/UV processes. Practice Periodical of Hazardous, Toxic, and Radioactive Waste Management 11, 20-27.
Chen and J.J. Pignatello, 1997. Role of quinone intermediates as electron shuttles in Fenton and photoassisted Fenton oxidations of aromatic compounds. Environ Sci Technol 31, 2399–2406.
Chinery, R.L., Gleason, A.K. A compartmental model for the prediction of breath concentration and absorbed dose of chloroform after exposure while showering.
Risk Analysis 1993, 13, 51-62.
Chu, W., Ma, C.-W., 2000. Quantitative prediction of direct and indirect dye ozonation kinetics. Water Research 34, 3153-3160.
Cleuvers, M., 2004. Mixture toxici of the antiinflammatory dugs diclofenac, ibuprofen, naproxen, and acetylsalicylic acid. Ecotpxicol. Environ. Safety, 59,
R- 3
309-315.
Coelho, A.D., Sans, C., Aguera, A., Jose Gomez, M., Esplugas S., Dezotti M., 2009.
Effects of ozone pre-treatment on diclofenac: Intermediates, biodegradability and toxicity assesment. Sci Total Environ 407, 3572-3578
Daughton, C.G., Ternes, T.A., 1999. Pharmaceuticals and personal care products in the environment: agents of subtle change. Environmental Health Perspectives 107, 907-938.
Daniel, U., Peter, M.H., Graham, A.G., Dennis, M., 1999. Modeling enhanced coagulation to improve ozone disinfection. J. Am. Water Works Ass, 91, 59-72.
Esplugas, S., Bila, D.M., Krause, L.G.T., Dezotti, M., 2007. Ozonation and advanced oxidation technologies to remove endocrine disrupting chemicals (EDCs) and pharmaceuticals and personal care products (PPCPs) in water effluents. Journal of Hazardous Materials 149, 631-642.
Farré, M., Petrovic, M., Barceló, D., 2007. Recently developed GC/MS and LC/MS methods for determining NSAIDs in water samples. Analytical and Bioanalytical Chemistry 387, 1203-1214.
Ferrari, B., Paxeus, N., Giudice, R.L., Pollio, A., Garric, J., 2003. Ecotoxicological impact of pharmaceuticals found in treated wastewaters: study of carbmazepine, clofibric acid, and diclofenac. Ecotox. Environ. Safe. 55, 359-370
Fernando, J.B., 2004. Ozone Reaction Kinetics for Water and Wastewater Systems.
Lewis, New York.
Gilbert, E., 1978. Reaction of ozone with organic compounds in dilute aqueous solution: Identification of their oxidation product. In: Rice, R.G., Cotruvo, I.A.
(Eds.). Ozone/Chlorine Dioxide Products of Organic Materials. International Ozone Association, Cleveland, pp. 227-242.
R- 4
Hammes, F., Salhi, E., Köster, O., Kaiser, H.-P., Egli, T., von Gunten, U., 2006.
Mechanistic and kinetic evaluation of organic disinfection by-product and assimilable organic carbon (AOC) formation during the ozonation of drinking water. Water Research 40, 2275-2286.
Heberer, 2002. Occurrence, fate, and removal of pharmaceutical residues in the aquatic environment: a review of recent research data, Toxicol. Lett. 131, 5–17.
Heberer, 2002. Tracking persistent pharmaceutical residues from municipal sewage to drinking water, J. Hydrol. 266, 175–189.
Hoigné, J., Bader, H., 1983. Rate constants of reactions of ozone with organic and inorganic compounds in water--I: Non-dissociating organic compounds. Water Research 17, 173-183.
Hohmann, U. Freier, M. Wecks and S. Hohmann, 2007. Degradation of diclofenac in water by heterogeneous catalytic oxidation with H2O2. Appl Catal B-Environ 70, 447–451.
Huang, W.J., Fang, G.C., Wang, C.C., 2005. The determination and fate of disinfection by-products from ozonation of polluted raw water. Sci Total Environ 345, 261-272.
Huang, C.H, Marinas, B.J., and Blake, D.M., 1993. The reaction mechanism between hydroxyl radical and organic matters. Ozone Sci. Eng., 12, 156-137
Huber, M.M., Canonica, S., Park, G.-Y., von Gunten, U., 2003. Oxidation of pharmaceuticals during ozonation and advanced oxidation processes. Environ Sci Technol 37, 1016-1024.
Jin, F.; Leitich, J.; von Sonntag, C., 1993. The superoxide radical reacts with tyrosine-derived phenoxyl radicals by addition rather than by electron transfer. J.
Chem. Soc., Perkin Trans. 2, 1583–1588
R- 5
Joss, A.; Zabcyznski, S.; Gobel, A; Hoffmann, B.; Loffler, D.; McArdell, C. S.; Ternes, T. A.; Siegrist, H., 2006. Biological degradation of phatmaceuticals in municipal wastewater treatment: Proposing a classification scheme. Water Research 40, 1686-1696
Jones, O.A.H., Voulvoulis, N., Lester, J.N., 2002. Aquatic environmental assessment of the top 25 English prescription pharmaceuticals. Water Research 36, 5013-5022.
Kim, J.-W., Ishibashi, H., Yamauchi, R., Ichikawa, N., Takao, Y., Hirano, M., Koga, M., Arizono, K., 2009b. Acute toxicity of pharmaceutical and personal care products on freshwater crustacean (Thamnocephalus platyurus) and fish (Oryzias latipes). The Journal of Toxicological Sciences 34, 227-232.
Kim, I.H., Tanaka, H., Iwasaki, T., Takubo, T., Morioka, T., Kato, Y., 2008.
Classification of the degradability of 30 pharmaceuticals in water with ozone, UV and H2O2. Water Science & Technology 57, 195-200.
Klavarioti, M., Mantzavinos, D., Kassinos, D., 2009. Removal of residual pharmaceuticals from aqueous systems by advanced oxidation processes.
Environment International 35, 402-417.
Kostopoulou, M., Nikolaou, A., 2008. Analytical problems and the need for sample preparation in the determination of pharmaceuticals and their metabolites in aqueous environmental matrices. TrAC Trends in Analytical Chemistry 27, 1023-1035.
Krognberg, L., Vieno, M. N., Härkki, H., Tuhkanen, T., Kronberg., L., 2010.
Occurrence of pharmaceuticals in rivers water and their elimination in a pilot-scale drinking water treatment plant. Environ Sci Technol 5077-5084 Langlais, B., D.A. Reckhow, and D.B. Brink, 1991. Ozone in water
R- 6
Treatment-Application and Engineering, Lewis Publisher.
Moeder, M., Schrader, S., Winkler, M., Popp, P., 2000. Solid-phase microextraction-gas chromatography-mass spectrometry of biologically active substances in water samples. Journal of Chromatography A 873, 95-106.
Thomas and M.J. Hilton, 2004. The occurrence of selected human pharmaceutical compounds in UK estuaries, Mar. Pollut. Bull. 49: 436–444.
Ternes, T.A., 1998. Occurrence of drugs in German sewage treatment plants and rivers. Water Research 32, 3245-3260.
Wishart, D. S., Knox, C., Guo, A. C., Shrivastava, S., Hassanali, M., Stothard, P., Chang, Z., Woolsey, J., 2006. DrugBank: a comprehensive resource for in silico drug discovery and exploration. Nucleric Acid Res. 34, D668-D672.
Paul, W., George, A., Gary, A., Jean, D., 1998. Relationships between the structure of natural organic matter and its reactivity towards molecular ozone and hydroxyl radicals. Water Research, 33, 2265-2276.
Pérez-Estrada, L.A., Malato, S., Gernjak, W., Aguera, A., Thurman, E.M., Ferrer, I., and Fernandez-Alba, A.R. , 2005. Photo-fenton degradation of diclofenac:
identification of main intermediates and degradation pathway. Environ Sci Technol 39: 8300-8306
Richardson, S.D., Thruston, A.D., Caughran, T.V., Chen, P.H., Collette, T.W., Floyd, T.L., Schenck, K.M., Lykins, B.W., Sun, G.-r., Majetich, G., 1999. Identification of New Ozone Disinfection Byproducts in Drinking Water. Environ Sci Technol 33, 3368-3377.
Rodríguez, I., Carpinteiro, J., Quintana, J.B., Carro, A.M., Lorenzo, R.A., Cela, R., 2004. Solid-phase microextraction with on-fiber derivatization for the analysis of anti-inflammatory drugs in water samples. Journal of Chromatography A 1024,
R- 7
1-8.
Rosal, R., Rodríguez, A., Perdigón-Melón, J.A., Mezcua, M., Hernando, M.D., Letón, P., García-Calvo, E., Agüera, A., Fernández-Alba, A.R., 2008. Removal of pharmaceuticals and kinetics of mineralization by O3/H2O2 in a biotreated municipal wastewater. Water Research 42, 3719-3728.
Schwaiger J., Ferling H., Mallow U., Wintermayr H., Neggele RD., 2002. Toxic effects of the non-steroidal anti-inflammatory drug diclofenac Part 1:
histopathological alterations and bioaccumulation in rainbow trout. Aquat Toxico 68, 301-315
Sein, M.M., Zedda, M., Turek, J., Schmidt T.C., Golloch, A., and Sonntag, C., 2008.
Oxidation of diclofenac with ozone in aqueous solution. Environ Sci Technol 42, 6656-6662.
Sotelo, J.L., Beltran, F.J., Benitez, F.J., Beltran-Heredia, J., 1987. Ozone decomposition in water: kinetic study. Industrial & Engineering Chemistry Research 26, 39-43.
Spiteller, M., Lamshöft. M., Zühlke, S., Stülten, D., 2008. Occurrence of diclofenac and selected metabolites in sewage effluents. Sci Total Environ 405, 310-316.
Staehelin, J., Hoigne, J., 1982. Decomposition of ozone in water: rate of initiation by hydroxide ions and hydrogen peroxide. Environmental Science & Technology 16, 676-681.
Stulten, D., Spiteller, M., et al. , 2008. Occurrence of diclofenac and selected metabolites in sewage effluents. Sci Total Environ 405: 310-318
Pérez-Estrada, L.A., Malato, S., Gernjak, W., Aguera, A., Thurman, E.M., Ferrer, I., and Fernandez-Alba, A.R., 2005. Photo-fenton degradation of diclofenac:
identification of main intermediates and degradation pathway. Environ Sci
R- 8
Technol 39, 8300-8306
Uetrecht, J. P., Zahid, N., Miyamoto, G., 1997. Oxidation of diclofenac to reactive intermediates by neutrophils, myeloperoxidase, and hypochlorous acid. Chem.
Res. Toxicol., 10, 414-419.
Verstraete, W., Forrez, I., Carballa, M., Verbeken, K., Vanhaecke, L., Schlüsener, M., 2010. Diclofenac oxidation by biogenic manganese oxides. Environ Sci Technol 44, 3449-3454.
Vogna, D., Marotta, R., Napolitano, A., Andreozzi, R., d'Ischia, M., 2004. Advanced oxidation of the pharmaceutical drug diclofenac with UV/H2O2 and ozone. Water Research 38, 414-422.
Weigel, R. Kallenborn and H. Hühnerfuss, 2004. Simultaneous solid-phase extraction of acidic, neutral and basic pharmaceuticals from aqueous samples at ambient (neutral) pH and their determination by gas chromatography–mass spectrometry, J. Chromatogr. A 1023: 183–195.
Zhang, Y.-J., Geißen, S.-U., and Gal, C., 2008. Carbamazepine and diclofenac:
removal in wastewater treatment plants and occurrence in water bodies.
Chemosphere 73: 1151-1161.
Zwiener, C., Frimmel, F.H., 2000. Oxidative treatment of pharmaceuticals in water.
Water Research 34, 1881-1885.
A-1
Appendix Appendix A-1
TOC
1. Method
According to NIEA W532.51C, promulgated by EPA, Republic of China.
2. Apparatus
Total organic carbon analyzer 3. Reagents
a. Reagent water
Use Milli-Q water as blank sample b. Phosphoric acid, H3PO4.
c. Organic carbon stock solution:
Dissolve 2.1254 g anhydrous potassium biphthalate, C8H5KO4 (KHP), in carbon free water and dilute to 1000 mL.
d. Carrier gas: Purified nitrogen e. Purging gas: Purified nitrogen 4. Procedure
a. Add Na2S2O8 (oxidizer) and H3PO4 (acidifier) to the containers of TOC analyzer.
b. Before the analysis of samples, warm up the analyzer for 30 minutes;
run blank for 60 minutes; run reagent water for 60 minutes.
c. Preparation of standard curve: Prepare standard organic carbon series by diluting stock solution to cover the expected range in samples.
d. Examine the samples
e. Wash the analyzer after the examination for 60 minutes.
A-2