Advanced oxidation treatment of dissolved organic matter from wastewater treatment plant secondary effluent using scattering electrical reactor

Abstract

In this study, scattering electrical reactor (SER) was applied to remove dissolved organic matter (DOM) from wastewater treatment plant secondary effluent (WTPSE), in order to investigate factors influencing removal effect including the electrolysis time, initial pH and current density, etc. The experiment results based on three-dimensional fluorescence spectrum showed that DOM from WTPSE consisted mainly of humic acids and soluble microbial metabolites which could be effectively decomposed through SER. Under the condition that initial pH was 6, current density was 12 mA/cm2, and the electrolysis time was 20 min, the removal rate of DOM could achieve 93.23%. The increase of degradation efficiency of DOM could be obtained by lowering initial pH. A function fitting model of SER was established, which could obviously simulate the relation between concentration of DOM and electrolysis time during the degradation of DOM. Infrared spectrum was applied to prove that the successful degradation of DOM could be explained by the appearance of O–H and the phenomenon that the anodes were corroded and dissolved during the process of electrolytic oxidation. The results also showed that the specific energy consumption of DOM degradation by Ru/Ir-coated electrodes was favorable, which was lower than the degradation by normal titanium electrodes.