Title : Plants with microbial fuel cells for green energy production, green sustainable remediation, and net zero emissions
Abstract:
The excessive use of fossil fuels increases greenhouse gas concentrations, leading to the greenhouse effect and climate change. Human activities also contribute to environmental pollution, including soil and water contamination. Plant-Microbial Fuel Cells (PMFCs) are an emerging technology capable of converting solar energy into electrical energy. This system consists of plants, substrates, microorganisms, and electrochemical components. Plants perform photosynthesis, absorbing carbon dioxide from the atmosphere. Their roots secrete organic matter, which is utilized by microorganisms, generating electrons that are transferred to the cathode via wires to produce electricity. PMFCs offer the advantages of utilizing solar energy as a power source and producing no secondary pollutants. They can be implemented in various configurations, including green roofs, farmlands, artificial wetlands, and environmental restoration projects. In an experiment, a PMFC system was constructed using sediment from Shuanglianpi Lake in Yilan County, Taiwan. The results showed that system voltage gradually increased over the first 27 days, reaching 366.75 mV. After plants were introduced on the 28th day, both voltage and power density significantly increased, stabilizing within a fixed range after 41 days. The highest average voltage recorded during the experiment was 616.80 mV on day 65, with a peak average power density of 21.53 mW/m². These findings indicate that PMFCs can generate stable electricity, contributing to sustainable energy development. PMFCs were also applied to remediate heavy metal pollution at contaminated sites in Taichung City, Taiwan. After 120 days of operation, chromium concentrations in the soil decreased from 255.01 mg/kg to 124.46 ± 21.86 mg/kg in the cathode soil and 214.52 ± 14.12 mg/kg in the anode soil. Copper concentrations dropped from 416.03 mg/kg to 172.46 ± 25.41 mg/kg in the cathode soil and 245.7 ± 22.67 mg/kg in the anode soil. Both removal rates were higher than those observed in control conditions without vegetation or with an open circuit. Additionally, over the same 120-day period, zinc concentrations in simulated zinc-contaminated groundwater decreased from 60.29 mg/L to 33.21 mg/L. These results demonstrate that PMFCs can simultaneously generate renewable biomass electricity and facilitate environmentally sustainable remediation, supporting efforts toward environmental protection and net zero emissions.
