Feasible design for electricity generation from Chlorella vulgaris using convenient photosynthetic conditions

Abstract

Many recent studies are concerned with low cost, easy to handle and alternative renewable energy as a feasible solution for the upcoming crisis of energy shortage. Microalgae are unicellular entities the can only depend on CO2, water and solar power to cover their nutritional needs. The current study is concerned with using algal cells in a polymeric hydrogel, as a cheap source of energy for electricity generation. Chlorella vulgaris has been proved to be a promising algal species for electricity generation, as compared with Micractinium reisseri. PVA hydrogel has been used for the immobilization of both algal species in order to protect them from the adverse surrounding conditions in addition to its ability to slowly release the required water molecules according to needs. Under these conditions, C. vulgaris showed the ability to generate 60 mV compared with 15 mV generated by M. reisseri. Scanning electron micrographs showed nano-threads that bind the C. vulgaris cells to each other, indicating the ability of algae to create nanowires that facilitate the electron transfer among algal cells and from cells to the nearest electrode. However, we would expect an increase in the produced potential with simultaneous amendment of environmentally polluted water, such as sewage or waste water. Both of FTIR and raman spectroscopy proved the presence of the characteristic groups of PVA hydrogel and proved the proper integration of the algal cells inside the hydrogel cavities.