Study on the treatment of osmium-containing waste followed by osmium recovery using supercritical fluids

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04312
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22060:Environmental systems for civil engineering-related
• Research Institution: The University of Tokyo
• Principal Investigator: Nunoura Teppei 東京大学, 環境安全研究センター, 准教授 (40444070)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: オスミウム / 超臨界水酸化 / 超臨界二酸化炭素抽出 / 廃棄物処理 / 四酸化オスミウム

Outline of Final Research Achievements

A novel treatment process of waste liquid/solid containing osmium, which has a high potential toxicity but also is a very precious metal element, was proposed and studied. This process is a combination of supercritical water oxidation and supercritical carbon dioxide extraction. First, supercritical water oxidation of simulated wastewater as well as actual wastewater containing osmium was studied and the effect of operational conditions and coexisting materials on the behavior of osmium compounds was measured. Also, behavior of simulated solid waste containing osmium in supercritical water oxidation was studied. At the same time, osmium tetroxide extraction by supercritical carbon dioxide was investigated under various experimental conditions by using simulated and actual wastewater, effluent from supercritical water oxidation treatment, and simulated solid waste as the extraction target samples.

Free Research Field

環境工学

Academic Significance and Societal Importance of the Research Achievements

本研究では、オスミウムを含有する模擬廃棄物及び実廃棄物を用いて検討を行いその挙動を明らかにした。本研究の成果は、これまでの基礎的な物質を用いた検討から一歩進んで現実の廃棄物を想定した検討であって、オスミウム系廃棄物の適切な無害化・有価物回収処理プロセスの実現に向けて大きく資するものである。有害廃棄物管理・持続可能な物質循環につながるためその社会的意義も極めて大きい。また、超臨界流体中のオスミウムの挙動に関する知見は、これまでに非常に検討例の少ないものであり、廃棄物処理技術の研究分野のみならず物質合成や反応工学の分野における応用にもつながり得るという点で、学術的にも大きな意義がある。