Cascade use of digestate from methane fermentation using marine biomass

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K21286
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Design and evaluation of sustainable and environmental conscious system; Naval and maritime engineering
• Research Institution: Osaka Prefecture University
• Principal Investigator: KURODA Kana 大阪府立大学, 人間社会システム科学研究科, 准教授 (70708023)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 海産バイオマス / メタン発酵 / 栄養塩の偏在 / ノリの色落ち / 鉄

Outline of Final Research Achievements

Ulva sp. (green seaweed) often proliferates explosively and piles up in shallows. This phenomenon is called “green tide,” caused by increased nutrient flow into an enclosed sea area. This research proposes that the digestate from methane fermentation using mixed biomass (Ulva sp. and food waste) can be applied to the cultivation of Pyropia yezoensis (edible laver seaweed, nori in Japanese), which has recently suffered from decolored phenomena because of decreasing nutrients. The results highlight that the significant absorption of nutrients and color recovery occurred because of digestate utilization, indicating its positive effects on decolored nori. Also, digestate can be expected to promote methane production that may be caused by iron derived from Ulva sp..

Free Research Field

海洋環境学

Academic Significance and Societal Importance of the Research Achievements

窒素やリンなどの栄養塩は，人間活動に欠かせないものであり，海洋環境の保全のためには栄養塩を適正に管理することが重要である。本研究成果により，栄養塩を適材適所に活用することが可能となり，社会的要請の高い「栄養塩の適正管理」の一助となる。また，メタン発酵は「再生可能エネルギー」「循環型社会の形成」に重要な役割を果たし，都市部での利用が急速に進んでいるものの，発酵残渣の利用に関する知見は乏しく，海を介した栄養塩循環の視点が欠けている。本研究成果は，海陸一体型の循環型社会の礎となる。