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

在本研究中，我们在大坂湾进行了调查和几种基础实验，以证明利用海洋生物质修复富营养化海域的环境的有效性，并开发了一些重要技术，如海藻转化为增值材料，大规模培养大型绿色藻类，海洋和废弃物-食物生物质的混合甲烷发酵等。我们还根据实地调查和实验获得的基础数据，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，该方案具有较好的环境修复和低碳效应，但在实际应用中存在一定的困难，如海洋生物质能源剩余量小、残渣肥料需求有限等。

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.