Economical and sustainable microbial peroxide-producing cell utilizing domestic sewage water and its contemporaneous treatment

Abstract

To boost growth and global competitiveness, a growing number of industries and sewage treatment plants are making “sustainability” and “cost-effectiveness” key goals in their strategy and vision. This movement is also spreading far beyond the small group of people who recognize as “green”. This is the first study to demonstrate that domestic sewage water can be utilized as anodic feed for the electrochemical production of H₂O₂ in the catholyte with simultaneous wastewater treatment in a microbial peroxide-producing cell (MPPC) designed cost-effectively utilizing a variety of catholyte and few electrode materials. The electrochemical output utilizing domestic wastewater resulted in maximum production of 62 mM H₂O₂ in a 37-day batch in the MPPC with 50 mM H₂SO₄ catholyte having a bare activated charcoal electrode. The constantly rising H₂O₂ production during the 37-day hydraulic retention time demonstrated the system's sustainability and efficiency in contrast to other reported studies. Cyclic voltammetry analysis of the catholyte with the Fenton process showed excellent redox peaks, indicating its applicability for in-situ pollutant degradation. The MPPCs had an overall 40%–60% and 65%–85% removal efficiency of biochemical oxygen demand and chemical oxygen demand. This study shows that a simple MPPC design with no extensive modifications can be efficient at producing H₂O₂ and simultaneously treating wastewater.