Degradation Of Antibiotic Sulfamethoxazole In Aqueous Solution By (Photo) Electro-Fenton Process

With the development of China’s pharmaceutical industry and drug consumption, a large number of toxic drugs pollutants go into the environment water. Studies have shown that antibiotic sulfa drugs can not be removed by conventional sewage treatment process but its residual concentration can be reduced by advanced oxidation process (Advanced oxidation Processes, AOPs). In acidic media and Fe2+system, generated electricity Fenton reaction which uses Hydroxyl free radical oxidation produced by generating H2O2and Fe2+to degrate organic was acclaimed. The essence of the electro-Fen ton method is:H2O2produced by the electrochemical method and (or) Fe2+as a continuing source of Fenton’s reagent and constantly replenished.Selectting four different specific surface area activated carbon fiber ACF-1000, ACF-1300, ACF-1500and ACF-1800, under no light,365nm UV irradiation and254nm UV irradiation, current strength for the system TOC, ammonia and pH changes were studied. Morphology and surface elemental changes before and after (Photo) Electro-Fenton reaction were analysed by using SEM and EDS analysis. Getting the following main results:1、Activated carbon fiber electrochemical hydrogen peroxide process was studied. Current intensity of0.24A generates the most hydrogen peroxide; acidic condition is conducive to the formation of hydrogen peroxide and the optimum pH is3.0; ultraviolet note lowers peroxide hydrogen production.2、Gas species impact on Fe2+and Fe3+is small. Current intensity impact on Fe2+and Fe3+transformation is large, best conversion current for Fe2+is0.12A, and the optimum conversion current for Fe3+is0.12A and0.08A.3、Current intensity, gas, metal ions, surface area of activated carbon fiber impact on hydroxyl radicals is large. With the same current intensity, generated amount of hydroxyl radicals is:O2> Air> None; passed into the same gas, current intensity0.12A generates the highest concentration of hydroxyl radicals; hydroxyl radicals concentration produced with diffirent metal ions presence is:Fe2+>Fe3+>Cu2+> Mn2+> Co2+; under the same condition, ACF-1800generates a higher concentration of hydroxyl radicals thanACF-1300.4、Degradation rate of SMX in descending order is:pEF, E-F, UV-E-H2O2, E-H2O2, anodic oxidation. Five different processes to SMX TOC removal rate in descending order is:pEF, E-F, UV-E-H2O2, E-H2O2, anodic oxidation.5、For four different specific surface areas ACF, no light,365nm UV irradiation or254nm UV irradiation, amount of ammonia generated in the reaction system is substantially raised with the increase of the current intensity. No light, current strength impact on Electro-Fenton removal of SMX solution TOC is great. Under365nm UV irradiation or254nm UV irradiation, current strength impact on Electro-Fenton removal of SMX solution TOC is not obvious.6、Activated carbon fiber morphology changes little before and after the (Photo) Electro-Fenton reaction. With the (Photo) Electro-Fenton reaction process, the sulfa metronidazole (SMX) is gradually mineralized substance, decomposition of small molecules. This reaction eaction mainly relys on generated hydroxyl radicals.