Effect of sulfur-oxidizing bacteria on leaching and volatilization of mercury from sulfur polymer mercury solidified/stabilized in waste landfills

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K20479
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 64020:Environmental load reduction and remediation-related
• Research Institution: National Institute for Environmental Studies
• Principal Investigator: Ogata Yuka 国立研究開発法人国立環境研究所, 資源循環領域, 主任研究員 (50714200)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 水銀 / 最終処分場 / 改質硫黄水銀固型化物 / 硫黄酸化細菌

Outline of Final Research Achievements

In order to reveal the effects of microbial reactions on the stability of sulfur polymer solidified/stabilized of mercury in waste landfills, we focused on sulfur-oxidizing bacteria to evaluate their effects on the leaching and volatilization of mercury from the mercury solidified/stabilized products. The coexistence of sulfur-oxidizing bacteria accelerated the volatilization of mercury from the mercury solidified/stabilized products, and the amount of mercury volatilization was 18-58 times higher than in the sterile system. On the other hand, there was no dissolved mercury detected, suggesting that the dissolved mercury volatilized quickly. It was also indicated that the rate and amount of mercury volatilization differed depending on the strain of sulfur-oxidizing bacteria. For the appropriate long-term management of mercury wastes in waste landfills, it is important to consider the control of mercury emissions through microbial reactions.

Free Research Field

環境工学

Academic Significance and Societal Importance of the Research Achievements

本研究成果は、今後需要が高まる最終処分場での改質硫黄水銀固型化物を用いた、長期的な適正管理方法の確立に貢献する。水銀固型化物からの水銀放出を抑制するためには、硫黄酸化細菌等の微生物反応の抑制が重要となることが示された。また、硫黄酸化細菌によって、水銀固型化物からの水銀の揮発が促進されるという、極めて新規性の高い知見を得た。