Degradation of anticancer drug 5-fluorouracil by Fenton and oxalic-Fenton process

It is urgent and necessary to develop effective methods to remove residual pharmaceuticals in aquatic environment,due to their potential ecological risk. This paper examined the degradation efficiency and reaction kinetics of an anti-cancer drug 5 fluorouracil( 5-FU) by Fenton process and oxalic-Fenton process. The results showed that the degradation rate of 5-FU reached 87. 55% by Fenton process,under the condition of initial pH of 3,Fe2+dosage of 5 mg·L-1,H2O2/ Fe2+molar ratio of 2∶1 and reaction time of 30 min,while the degradation rate of 5-FU reached 100% by oxalicFenton process under the condition of pH range of 2. 5—4,Fe2+dosage of 5 mg·L-1,H2O2/ Fe2+molar ratio of 2∶1,oxalic dosage of 5 mg·L-1and reaction time of 30 min. The applicable pH range for oxalic-Fenton process( 2. 5—6) was obviously broader than that for Fenton process( 2—4). The degradation of 5-FU by Fenton process and oxalic-Fenton process both showed an initial rapid phase( 0—2 min) and subsequent retarded phase,and the degradation kinetic fitted the combined firstorder kinetic model. The removal rate of 5-FU by oxalic-Fenton process is higher than Fenton process.