粉砕コンクリート廃棄物の溶解運動: pHが浸出行動に与える影響
Danielle C Tompkins1, Douglas I Stewart2, James T Graham3
1School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK.
Waste management (New York, N.Y.)
|August 31, 2025
まとめ
粉砕コンクリート廃棄物 (CCW) の浸出は pH に依存する. アルカリ条件は,カルシウムシリケート水素相の一致溶解を促進し,低 pH は,炭酸塩溶解によるカルシウム浸出を増加させ,廃棄物の処理予測に影響を与えます.
科学分野:
- 環境科学
- 地化学
- 材料科学
背景:
- 建物の解体により大量のコンクリート廃棄物が発生し,廃棄物処理に問題が生じます.
- 埋め込み材料として砕けたコンクリート廃棄物を再利用するには,環境への潜在的な影響,特に浸出を理解する必要があります.
- CCWの反応性セメント相は溶解し,構成要素を環境に放出することができます.
研究 の 目的:
- イギリスの核施設からCCWの短期的な溶解運動を調査する.
- 液体のpHの関数として主要元素と微量元素の浸出率を決定する.
- 様々な廃棄シナリオでCCWの浸出行動の予測を伝えるために.
主な方法:
- 脱離水,酸性およびアルカリ性浸出剤を用いた浸出試験を実施した.
- 主要元素と微量元素の擬定安定状態の浸出率を測定した.
- 溶解に対する効果を研究するために,溶液のpHを体系的に変化させました.
主要な成果:
- アルカリ性pH (> 10) では,CaとSiは類似の浸出率を示し,カルシウムシリケート水素相の一致した溶解を示した.
- pH10以下では,炭酸カルシウム溶解と不一致のC-S-H相溶解によるpHの低下に伴い,溶液中のCa/Si比が増加した.
- Mg,Fe,Mnの浸出はpHに依存し,溶解性が制御され,他の微量元素は主にpHに依存しない浸出を示した.
結論:
- CCWからの溶液化学と元素の移動性は,pHに強く依存しています.
- 塩分による浸出の理解は,CCWの再利用の環境安全性を評価する上で極めて重要です.
- この研究は,地下水や流星水の相互作用を含むシナリオでCCWの浸出を予測するためのデータを提供します.
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