Study on the treatment of osmium-containing waste liquid/solid using supercritical fluids

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K00593
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental engineering and reduction of environmental burden
• 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): 2017-04-01 – 2020-03-31
• 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 is not only a highly toxic substance but also a precious metal, was studied. This process consists of supercritical water oxidation of osmium-containing waste and supercritical carbon dioxide extraction of osmium tetroxide from water phase. First, supercritical water oxidation of simulated wastewater containing osmium compounds and some coexisting materials and waste solid was studied and the effect of operational conditions and coexisting materials on the behavior of osmium compounds was measured. Behavior of osmium tetroxide in supercritical carbon dioxide extraction as well as its recovery was also investigated quantitatively under various experimental conditions. In addition, effect of ultrasonic irradiation on the wastewater containing osmium compounds and organic substances was investigated to clarify their oxidation behavior.

Free Research Field

環境工学

Academic Significance and Societal Importance of the Research Achievements

本研究では、オスミウム含有廃棄物の処理技術開発を目的に、廃棄物中オスミウム物質の諸反応について検討を行いその挙動を明らかにした。超臨界流体中のオスミウムの挙動に関する知見は、これまでに筆者の研究グループ以外に報告例のないものであって、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学術的に非常に意義の大きい成果である。加えて、本研究の成果は、従来は処理困難であったオスミウム廃棄物について、適切に無害化・有価物回収を行う処理プロセスの確立につながるものであり、有害廃棄物管理・持続可能な物質循環に大きく資するため、その社会的意義も極めて大きい。