Development of nutrient and energy recovery technology


Water hyacinth is difficult to dispose of or utilize as it is, so we will develop a technology to effectively utilize it after separating it into compressed juice and solid residue through crushing and pressing. The compressed juice will be decomposed by microorganisms that work under an anaerobic environment without oxygen to recover biogas for a heat source. The nutrient-rich waste liquid of the decomposition (anaerobic digestion effluent) will be used in theme 3 to produce valuable resources, such as Spirulina, vegetables, and crops. On the other hand, the solid residue will be carbonized to make biochar, then it will be solidified to an appropriate size for fuel or mixed in the field as a soil conditioner to increase the yield of crops.

Technical features of the theme

We aim to achieve low-cost and energy-saving treatment by conducting an anaerobic digestion system as fast as possible. In order to achieve this goal, we will study techniques to maintain a high density of microorganisms in the anaerobic digestion reactor by using normally discarded materials such as bagasse as a home for microorganisms. We will also investigate techniques to facilitate decomposition by physical pretreatment without using chemicals. In the carbonization process, we will investigate the effect of the difference in moisture content of the solid residue on biochar production, and the optimal carbonization conditions for different applications, such as fuel or soil conditioner.

Institution in charge and members

Japanese side

Institute of Plankton Eco-engineering, Soka University: Shinichi Akizuki, Masatoshi Kishi
Faculty of Science and Engineering, Soka University: Shinjiro Sato, Tatsuki Toda

Ethiopian side

Bahir Dar Institute of Technology Faculty of Chemical and Food Engineering:Nigus Gabbiye, Hailemariam Zewudu
Collage of Nature and Computational Science, Injibara University:Bulti Kumera
Collage of Agriculture, Food and Climate Science, Injibara University:Mulugeta Tamer, Ewunetu Tazebew