Mercury mass balance in simulated landfill lysimeters of mercury wastes: Selection of stabilization methods and landfill conditions for long-term stability of landfilled mercury waste

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K06623
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Civil and environmental engineering
• Research Institution: Fukuoka University
• Principal Investigator: Yanase Ryuji 福岡大学, 公私立大学の部局等, 教授 (20131849)
• Co-Investigator(Kenkyū-buntansha): 佐野 彰 福岡大学, 工学部, 助教 (90432070)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 水銀廃棄物 / 埋立処分 / 水銀流出特性 / 水銀廃棄物の埋立手法

Outline of Final Research Achievements

The Minamata Convention on Mercury (2017) emphasized mercury (Hg) preventative management. Hg release from landfills poses serious health and environmental risks. We investigated Hg behavior of sulfurized/solidified Hg wastes using lysimeters simulated landfill to ensure the safety of landfilled Hg wastes. The five years lysimeter experiment showed sulfurized Hg (HgS) waste become unstable in landfill situations; dissolved Hg was detected in leachate. Cement solidification to HgS waste enhanced the stability in landfill situations; Hg emission from lysimeter with the solidified HgS waste was extremely law (less than 0.001%). And then, comparison of the lysimeter experiment for different landfill types and patterns indicated that semi-aerobic type landfill inhibited Hg emission and aquifer and alkaline components in landfill layer were related to Hg dissolution and diffusion.

Free Research Field

工学

Academic Significance and Societal Importance of the Research Achievements

水銀廃棄物の埋立処分に伴う水銀流出抑制に必要な最適な条件は、廃水銀を硫化物化した黒色硫化水銀の固化物が対象となる。また、最適な埋立条件は洗浄した固化物を準好気性埋立地の上層・中層域の非滞水部へ埋立処分することで、浸出水や大気拡散による水銀の流出が法規制を満足でき、長期亘って水銀流出の抑制が可能で、水銀廃棄物の処理処分時の環境対策として提言できた。