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海洋生物质的调查和若干基础性实验，验证了利用海洋生物质的环境修复对富营养化海域的有效性，并开发了海藻转化为增值材料、绿色巨藻的大规模养殖、海洋和废物-食物生物质混合甲烷发酵等重要技术。基于野外调查和实验获得的基础数据，对多种生物质收集和处理系统进行了环境和经济评估。结果表明，适宜的情景可带来良好的环境修复效果和低碳效应，但这一概念在实际应用中基本存在一些困难，如海洋生物质能量剩余量小、剩余物作为肥料的需求有限等。

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.