Degradation of cyclophosphamide and 5-fluorouracil in water using UV and UV/H2O2: Kinetics investigation, pathways and energetic analysis. Issue 1 (February 2017)

• Record Type: Journal Article
• Authors: Zhang, Yiqing; Xiao, Yongjun; Zhang, Jiefeng; Chang, Victor W.C.; Lim, Teik-Thye
• Is Part Of: Journal of environmental chemical engineering. Volume 5:Issue 1(2017:Mar.)
• Page Start: 1133
• Page End: 1139
• Publication Date: 2017-02
• Subjects: Cyclophosphamide -- 5-Fluorouracil -- UV/H2O2 -- Matrix species -- Electrical energy per order -- Degradation pathways; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2017.01.013
• Languages: English
• ISSNs: 2213-2929

Abstract

Highlights: UV/H2 O2 is effective towards CSDs degradation. Degradation pathways were investigated during UV and UV/H2 O2 . Optimal H2 O2 dose is obtained based on electrical energy analysis. Presence of NOM and inorganic anions inhibits CSDs degradation. Abstract: The photodegradation of cyclophosphamide (CP) and 5-fluorouracil (5FU) in water was investigated by low-pressure UV and UV/H2 O2 processes. The degradation effect of the two cytostatic drugs (CSDs) can be expressed using a pseudo first-order kinetic model in both UV and UV/H2 O2 process. Their photodegradation effect in direct UV system significantly increases with the addition of H2 O2 due to HO generation. At low H2 O2 dose, the degradation efficiency of CSDs increases with oxidant concentration; however, excess H2 O2 at higher dose reacts with HO and inhibits CSDs degradation. The optimal H2 O2 dose is 0.2 mM for both CSDs degradation based on the electrical energy analysis. The photodegradation effect of CSDs decreases in the presence of NOM, HCO3 − or Cl −, and increases with NO3 − . Treated water (TW) from a water treatment plant and secondary effluent (SE) from a wastewater treatment plant was employed as natural waters to evaluate the potential application of UV/H2 O2 . High concentration of alkalinity, NOM and Cl − in SE decreases the degradation efficiency of CSDs significantly. Transformation by-products of CSDs were detected to propose their potential degradation pathways.