J Water SRT - Aqua 54 (2005) 403-410
Effect of O3/H2O2 molar concentration ratio at different pH values on cyclophosphamide degradation
Mayra Bataller Venta, Carlos Hernández Castro, Lidia Asela Fernández García, Adaris López Marzo, Eliet Véliz Lorenzo and Caridad Álvarez Álvarez
Ozone Research Center, PO Box 6414, Playa, Havana,Cuba, Tel.: 53 7 271-1157, 53 7 271-1335, mayra.bataller@cnic.edu.cu, ozono@infomed.sld.cu
Ozone Research Center, PO Box 6414, Playa, Havana,Cuba, Tel.: 53 7 271-1157, 53 7 271-1335, mayra.bataller@cnic.edu.cu, ozono@infomed.sld.cu
Ozone Research Center, PO Box 6414, Playa, Havana,Cuba, Tel.: 53 7 271-1157, 53 7 271-1335, mayra.bataller@cnic.edu.cu, ozono@infomed.sld.cu
Ozone Research Center, PO Box 6414, Playa, Havana,Cuba, Tel.: 53 7 271-1157, 53 7 271-1335, mayra.bataller@cnic.edu.cu, ozono@infomed.sld.cu
Ozone Research Center, PO Box 6414, Playa, Havana,Cuba, Tel.: 53 7 271-1157, 53 7 271-1335, mayra.bataller@cnic.edu.cu,ozono@infomed.sld.cu
Ozone Research Center, PO Box 6414, Playa, Havana,Cuba, Tel.: 53 7 271-1157, 53 7 271-1335, mayra.bataller@cnic.edu.cu,ozono@infomed.sld.cu
ABSTRACT
The effect of O3/H2O2 liquid phase molar concentration ratio at different pH on cyclophosphamide degradation rate was evaluated. The combination of O3/H2O2 leads to an increase of cyclophosphamide degradation rate, compared with single ozonation at the same pH and ozone dosages. It was found that cyclophosphamide degradation rate with O3/H2O2 depends on pH for the molar concentration ratios under study, the fastest degradation being observed for molar concentration ratio near 3.4 at pH 7 (80% degradation in 3 minutes). Pseudo-first order reaction rate constants for cyclophosphamide degradation were determined under the experimental conditions of this study. Cyclophosphamide was not detected after 15 minutes of reaction, but only a partial mineralization was obtained, evidenced by a total organic carbon removal lower than 60%. By attenuated total reflection infrared spectroscopy and electrospray ionization tandem mass spectrometry, 4-ketocyclophosphamide was identified as one of the main reaction products at pH 7 and 3.4 molar concentration ratio.
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