An actual proof research on restoration of anoxic sea area by utilization of marine biomass

本研究在大阪湾开展了调查和几种基础实验，以证明利用海洋生物物质进行富营养化海域环境恢复的有效性，并开发了一些重要技术，如海藻转化为附加值材料、大规模培养绿色大型藻类、海洋和垃圾-食物生物质混合沼气发酵等。我们还根据实地调查和实验获得的基本数据，对生物质收集和处理系统的多种方案进行了环境和经济评估。结果表明，该方案具有良好的环境恢复效果和低碳效果，但这一概念在实际应用中存在一些困难，如来自海洋生物质能的剩余量较小，残渣作为肥料的需求有限。

In this research, we carried out surveys in Osaka Bay and several kinds of fundamental experiments to proof usefulness of environmental restoration for eutrophic sea area utilizing marine biomass, and developed some important technologies, such as conversion of seaweeds to value-added materials, large-scale cultivation of green macroalgae, mixed methane fermentation of marine and waste-food biomass, and so forth. We also performed both environmental and economic evaluations for plural scenarios of biomass collection and treatment systems based on the fundamental data obtained by the field surveys and experiments. The results suggested that the suitable scenario leads to good performances of environmental restoration and low carbon effect, but this concept basically involves some difficulties for practical use, e.g. small surplus of energy from marine biomass, limit of demand of residue as fertilizer.