Enhancement of the Biodegradability of Ethylenediamine in Wastewater by Sono-Fenton Degradation

Abstract

This study tried to use a sono-Fenton process to degrade the ethylenediamine in wastewater for enhancing its biodegradability and investigated the effect of experimental parameters, such as H2O2 and Fe2+ concentration and reaction temperature, on the degradation of ethylenediamine. The reaction was initiated at ethylenediamine concentration of 50 mg/L and pH 3. Experimental results indicated that the degradation of ethylenediamine was insignificant with a sole ultrasound for 60 min reaction, where the biodegradability (BOD5/COD) was slightly increased from 0 to 0.2. More than 50% of ethylenediamine degradation coupled with 20% DOC (dissolved organic carbon) removal was found at 100 mg/L H2O2 and 40 mg/L Fe2+ in sono-Fenton process. Biodegradability of treated wastewater was also effectively increased to 0.7, which could be supposed as a biodegradable wastewater. Five reaction temperatures were carried out in this study, where the 25°C was more suitable than other reaction temperatures for the degradation of ethylenediamine in wastewater. Based on the results shown in this study, sono-Fenton process not only could degrade the ethylenediamine and render it biodegradable but it could also be suitable as a pre-treatment method for the degradation of refractory ethylenediamine in wastewater before entering the biological treatment units.