Résumé
Nowadays, the world is in continuous demand for new alternative replacements to the fossil fuels as a source of energy, which are harmful to the environment, expensive, geographically limited in resources, and most of all depletable. The bio-photovoltaics (BPVs) is an advanced green alternative energy and an interesting area of research that attracts many researchers considering its innovative nature and potential applications. In this context, a plant Biofuel cell (PBFC) has been conceived for the production of electricity by using photosynthesis as a stimulant for the electrochemical activities of the microbes in the rhizosphere. Both thebioanode and biocathode were dipped inside a container full of garden soil, in which the plant “Crassula Ovata” was planted. The cathode was placed at the edge of the container far enough from the roots, whereas the bioanode was placed close to them where the microbes of the rhizosphere are supplemented with nutrients. The production of the electricity was achieved at the bioanode by the oxidation of the organic matter (glucose resulting from the photosynthesis) by means of the microorganisms present in the garden soil. The plant acted as stimulant for the microorganisms via photosynthesis, while the oxygen O2 was reduced at the cathode. The performance of the PBFC has been observed in different lighting conditions and in absence of the plant to demonstrate the role played by photosynthesis in energy production. The results obtained so far, showed that photosynthesis is an effective stimulant for the performance of the PBFC (the power density was 330 nW/cm2 in the brightest lighting condition, compared to 130 nW/cm2 in the absence of light and 126 nW/cm2 without the plant). Furthermore, this bio-electrochemical process is clearly on the lower side due to it being biological in nature. Hence, an innovative solution for this particular problem has been proposed, which is to implement an adequate amplificationsystem composed of an operational amplifier, a solar photovoltaic panel and a boost direct current converter was employed to improve the low electric energy production to reach the output voltage 2670 mV against 91mV without amplification. The performance of the bio-electrochemical device was tested in the desalination of an aqueous solution containing heavy metals via electrodialysis using the amplified energy. The electrodialysis (ED) achieved 28.75 % after three hours, which is quite interesting considering the PBFC’s bioenergy output.