Kurita Water Industries had a demonstration test regarding microbial fuel cell that we are developing under the assumption to incorporate into wastewater treatment systems, by its actual scale size single cell and actual wastewater in November 2024. The Demonstration Test confirmed the continuous operation of electrical devices by generating electricity and provided further insights into its practical application.
The microbial fuel cell is a system that utilizes a technology to enable organic matter in wastewater, which is converted to sludge and discharged as waste in conventional aerobic treatment process, to convert electricity directly by utilizing microorganisms called the "Electricity-Generating Bacteria," which can emit electrons when they decompose organic matter. Its research and development toward practical application are underway at research institutes and companies worldwide. The utilization of this system is expected to contribute to the reduction of energy consumption and CO2 emissions in the wastewater treatment process and to be used for “energy-harvesting, ” generating electricity from wastewater and wastes and using it. Then, it will be utilized in large-scale business sites such as factories, consumer sites such as restaurants, and emergencies when disasters occur.
In Kurita, microbial fuel cells are developed to utilize and apply technologies and knowledge of water treatment, which has been cultivated for a long time. A demonstration test in 2022, using synthetic wastewater in the wastewater treatment process, was achieved to upsize microbial fuel cells to actual scale size(*1). The Demonstration Test was held to confirm the continuous operation of electric devices only by electricity generated by microbial fuel cells using actual wastewater for practical application of energy-harvesting use.
The Demonstration Test was conducted over five days in early November at a campsite in Saikai City, Nagasaki Prefecture, with the cooperation of Nishimu Electronics Industries Co., Ltd. (Head Office: Fukuoka City, Fukuoka Prefecture,) with the combination of their self-treatment flush toilet "TOWAILET"(*2), which is capable of purifying human waste and reusing it as flush water and is also being used to support disaster-stricken areas, and our microbial fuel cell currently under development. In the Demonstration Test, we tried to operate a digital clock and small illumination consisting of 60 LED bulbs, which each move by AA batteries, using electricity generated by actual scale cells of microbial fuel cells and supplied a part of wastewater treated by TOWAILET.
As a result, 0.6 to 0.8 Wh/g-COD Cr of electricity was obtained per amount of organic matter removed from wastewater throughout the test period, and the electrical equipment was successfully operated continuously. In addition, by improving the fuel cells, the amount of power generated per cell volume during the test period reached a maximum of 550 W/m3, more than double the level in 2022. Based on the continuous operation of electric devices confirmed in this test, we will proceed with their technological development, considering their utilization as a general power source in times of disaster and also aiming for their practical use with advanced features of this technology used for industrial wastewater treatment by conducting a long-term demonstration test using actual wastewater.
The Kurita Group will continuously aim to contribute to realizing a sustainable society by creating innovation that provides new values to customers and society by utilizing our “knowledge of water” cultivating since its establishment.
