Removal of chemical oxygen demand (COD) from hospital wastewater by electro fenton process using graphite–graphite electrochemical system

Abstract

Removal of COD from hospital wastewater generated from Al- Diwaniyah hospital located in Iraq was achieved using graphite–graphite electro-Fenton (EF) system. The effect of various operational parameters on the COD removal efficiency was investigated based on response surface methodology (RSM). Optimal conditions were current density of 20mA/cm2, FeSO4 concentration of 0.697 mM and time of 48.687 min. At these conditions COD elimination efficiency of 97.964 % was achieved at a specific energy consumption of 10.78 kWh/kg. The results indicated that time had the least effect on the COD removal efficiency, while the impact of current density had the greatest effect, followed by the FeSO4 concentration. The adequacy of the model equation was confirmed by its high R2 value (99.62%). The present study shows that graphite–graphite EF system was an efficient tool for removing of COD from hospital wastewaters.