In this study, a microbial fuel cell was integrated into a hydroponic system (MFC-Hyp) using a ceramic membrane as a separator. The MFC-Hyp is a passive system that allows the transport of nutrients from wastewater in the microbial fuel cell (MFC) to water in the hydroponic vessel (Hyp) through a ceramic membrane separator, with no external energy input. The performance of this system was examined using potato-process wastewater as a source of energy and nutrients (K, P, N) and garlic chives (Allium tuberosum) as a hydroponic plant. The results showed that based on dry weight, the leaves of Allium tuberosum grew 142% more in the MFC-Hyp than those of the plant in the Hyp without the MFC, in a 49-day run. The mass fluxes of K, P, and NO₃⁻-N from the MFC to the Hyp through the ceramic membrane were 4.18 ± 0.70, 3.78 ± 1.90, and 2.04 ± 0.98 µg s⁻¹m⁻², respectively. It was apparent that the diffusion of nutrients from wastewater in the MFC enhanced the plant growth in the Hyp. The MFC-Hyp in the presence of A. tuberosum produced the maximum power density of 130.2 ± 45.4 mW m⁻². The findings of this study suggest that the MFC-Hyp system has great potential to be a “carbon-neutral” technology that could be transformed into an important part of a diversified worldwide energy–water–food supply system.

Plant microbial fuel cells (P-MFCs) are sustainable and eco-friendly technologies, which use plant root exudates to directly nourish the electrochemically active bacteria (EABs) to generate sustainable electricity. However, their use in evaluating plant growth has been insufficiently studied. In this study, interconnection between plant growth and the production of bioelectricity was evaluated by using P-MFCs inoculated with 642.865 mL ≅ 643 mL of livestock’s urine such as cow urine, goat urine, and sheep urine. The greatest mean stem diameter of 0.52 ± 0.01 cm was found in P-MFC-3 inoculated with goat urine, while the P-MFC-2 treated with cow urine reached a higher average number of roots with a value of 86 ± 2.50 (95% improvement) (p < 0.05). Besides, P-MFC-4 presented greater height of 50.08 ± 0.67 cm. For polarization curve experiment a higher maximum power density of 132 ± 11.6 mW m⁻² (931 mA m⁻²) was reached with cow urine; in turn, with regard to the long-term operation, the same reactor indicated a higher maximum average power density of 43.68 ± 3.05 mW m⁻². The study’s findings indicated that Stevia P-MFC inoculated with urine was a good option to increase the biomass amount for the agricultural plants along with power generation. Further, this study opens the way for more investigation of evaluating the impact of P-MFC on plant growth.

Editorial: Advances and Trends in Development of Plant Factories