Fertilizer made from animal waste could enable space agriculture: Research
The study aims to address the problem of food production in closed environments
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An innovative study conducted recently by a team of Japanese researchers led by Junior Associate Professor Norihiro Suzuki from Tokyo University of Science and published in the New Journal of Chemistry of the Royal Society of Chemistry. In this study, Dr Suzuki and his team aimed to address the problem of food production in closed environments, such as those in a space station.
Realizing that farmers have used animal waste as fertilizer for thousands of years, as a rich source of nitrogen, Dr Suzuki and his team have been investigating the possibility of manufacturing it from urea (the main component of urine), to make a liquid fertilizer.
The research team - which also includes Akihiro Okazaki, Kai Takagi, and Izumi Serizawa from ORC Manufacturing Co. Ltd., Japan - devised an electrochemical process to derive ammonium ions (commonly found in standard fertilizers) from an artificial urine sample. Their experimental setup was simple: on one side, there was a reaction cell, with a boron-doped diamond (BDD) electrode and a light-inducible catalyst or photocatalyst material made of titanium dioxide. On the other, there was a counter cell with a simple platinum electrode. As current is passed into the reaction cell, urea is oxidized, forming ammonium ions.
The research team then examined whether the cell would be more efficient in the presence of the photocatalyst, by comparing the reaction of the cell with and without it. They found that while the initial depletion of urea was more or less the same, the nitrogen-based ions produced varied both in time and distribution when the photocatalyst was introduced. Notably, the concentration of nitrite and nitrate ions was not as elevated in the presence of the photocatalyst. This suggests that the presence of the photocatalyst promoted ammonium ion formation.