evaluation and optimization of electro-fenton process in removal of amoxicillin antibiotic using chelating agents at high ph values from aqueous solutions

Antibiotics are among the most consumed drugs worldwide. these compounds enter the environment from different sources, adversely affecting human and animal health given their high persistence and stability in the environment. conventional water and wastewater treatment processes have not been designed for removal of such materials. thus, a suitable method should be devised for removal of these compounds. among antibiotics, amoxicillin (amx) has the minimum metabolism. the aim of this research is the removal of amx using electro-fenton (ef) method from aqueous solutions. one of the most important disadvantages of the electro-fenton method is its high efficiency at acidic ph, causing secondary contamination. as such, for resolving this issue, chelating agents can be used. in this study, the effects of important parameters have been examined on amx removal efficiency including initial concentration amx (20-120) mg/l, initial ph (3-7), current intensity (10-130) ma, and edta concentration (0-1) mm as chelating agent via design of experiment method. this paper introduces a simplified version of quadratic polynomial response surface methodology (rsm). after analysis of variance, it was found that all examined variables were significant and the model had sufficient validity. the results showed that edta in addition to ph has also been influential in enhancing removal efficiency. regarding the optimal conditions for the examined parameters, the initial concentration of amx 24 mg/l, the current intensity 85 ma, initial ph 5.6, and edta dose 0.6 mm, showed 95.71% amx removal, eventually. also, a graphite cathode made of pencil was used for constant production of hydrogen peroxide during the process. the extent of electric energy consumption at the optimal point was obtained 0.86 kwh/m3.