Optimization and Utilization of Microbial Electrolysis Cells in Waste to Product Applications

As the world searches for cleaner and more sustainable energy solutions, turning waste into fuel is an increasingly attractive strategy. This research focuses on microbial electrolysis cells, a new technology that uses bacteria and a small amount of electricity to convert organic waste—like food scraps or wastewater—into useful gases such as hydrogen and methane. These gases can be used as energy sources to reduce dependency on more traditional fuels. This thesis tackles two key challenges that limit the real-world use of microbial electrolysis systems. First, it introduces a simpler and more effective method to stop hydrogen losses in single-chamber cells. This was done by periodically applying a short electric shock to the system, which produced small amounts of oxygen that disrupted the microbes responsible for hydrogen consumption. With this approach, hydrogen production improved dramatically, while disruptive microbes were inhibited without inhibition of the beneficial, electroactive microbes. Second, the research studied how different system settings affect performance in a combined process known as bioelectrochemical anaerobic digestion. This process merges microbial electrolysis with traditional anaerobic digestion—used in many wastewater treatment systems—to further improve organic degradation and energy recovery. The study tested how electrode surface area, applied voltage, and salinity levels in the system influenced gas production, energy recovery, and microbial activity. The results showed that all tested conditions increased biogas output and organic degradation compared to traditional systems. The best performance was achieved with moderate salt levels, which balanced electrical conductivity with microbial health, leading to twice the biogas output and 350% energy efficiency. In summary, this research presents practical innovations that improve both the efficiency and sustainability of waste-to-energy systems. These findings offer valuable insights for designing future technologies that convert waste into clean energy while reducing costs.