Utilization of Anaerobic Digestate as Fertilizer for Discoloration of Neopyropia yezoensis

Abstract

The present study investigates the potential usage of anaerobic digestate as fertilizer for discoloration of Nori. Laboratory experiments about the color recovery of Nori using anaerobic digestate demonstrated that the value of L* (brightness) decreased and became closer to black, and the value of a* (photosynthesis pigments) increased, indicating that anaerobic digestate worked properly as a source of nitrogen (NH₄-N), and was effective in the improvement of discoloration of Nori. Furthermore, there are no significant differences of the heavy metal content between in the cultivated Nori and natural Nori, suggesting further development of digestate as fertilizer of Nori.