Low-temperature treatment of domestic sewage by electrokinetic-based reactor

• Published in: Biomass conversion and biorefinery 2024-08, Vol.14 (16), p.18683-18695
• Main Author: Lagum, Abdelmajeed Adam
• Format: Article
• Language: English
• Subjects: Biotechnology; Energy; Original Article; Renewable and Green Energy
• ISSN: 2190-6815; 2190-6823
• DOI: 10.1007/s13399-023-04034-x

In this work, an electrokinetic-based (EK) reactor was coupled with a biodegradation process to improve the performance of treatment facilities in cold regions. Subsequently, the effects of electric current density (CD) and temperature on chemical oxygen demand (COD) and nutrient removal were investigated in a series of EK bioreactors. Moreover, the potential electro-stimulation of microbial biomass was evaluated. In this experiment, the treatment of synthetic wastewater at different operational temperatures (8, 13, and 20 °C), CD ranging between 1 and 2 mA/cm 2 , and electrical exposure regimes were performed. The results indicated that, at the lower temperature of 8 °C, the EK-based bioreactor with a CD of 1.5 mA/cm 2 at 60 s–ON/180 s–OFF contact mode achieved superior removal efficiencies of impurities over the control bioreactor. The removal of COD, NH 4 + - N , and PO 4 - P was higher than the control bioreactor by 32.6%, 75.9%, and 77% respectively. The outcomes also demonstrated that a CD of 1 mA/cm 2 with an operation mode of 60 s-ON/300 s-OFF was very effective in impurities removal at 20 °C leading to lower energy consumption and treatment costs. Furthermore, it was suggested that the adequate CD application induced microbial biomass responsible for COD and NH 4 + bio-utilization. Overall, the alternative EK approach presented in this work could improve the degradation rate by electrically stimulated biomass and optimize the performance of existing treatment plants operated at cold temperatures. Finally, this work establishes a viable approach for either retrofitting existing processes or constructing new wastewater facilities.