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年度	110	專案性質	實驗性質
專案類別	研究專案	研究主題	整治
申請機構	台灣大學	申請系所	環境工程學研究所
專案主持人	席行正	職等/職稱	教授
專案中文名稱	利用可磁性回收之綠色覆蓋材料整治多重重金屬污染底泥
中文關鍵字	活性覆蓋, 底泥, 多重重金屬, 生物炭, 綠色整治
專案英文名稱	Using magnetic recoverable green materials for active capping to remediate multiple heavy metal contaminated sediment
英文關鍵字	active capping, sediment, multiple heavy metal, green remediation, biochar
執行金額	1,020,000元
執行期間	2021/1/1 至 2021/12/31
計畫中文摘要	伴隨著數十年來之工業化發展，有害重金屬持續釋出於環境中，對自然環境及人類之健康產生迫切之風險。其中，汞(Hg)、銅(Cu)、鉻(Cr)、鋅(Zn)、鎳(Ni)、鎘(Cd)、鉛(Pb)及砷(As)等八大重金屬因其高毒性，於國內外皆為土壤地下水重點管制對象。自然水體底泥之整治在技術上及經濟層面皆有極高之挑戰，除了整治費用昂貴的疏浚法外，目前唯有現地活性覆蓋法較具有實務潛力。活性覆蓋法之核心概念為將污染底泥之表層鋪設薄層之活性覆蓋材料，以降低污染物釋出之風險。本團隊在過去針對活性覆蓋法之研究中，已逐步證實本技術能有效抑制 Hg、Cu、Cr、Zn 及 Ni 的釋出，使此技術具有模場潛力。儘管如此，現地整治後重金屬之長期穩定性為需要克服之隱憂。爰此，本研究將開發磁性可回收之吸附材料，期使現地活性覆蓋材料在整治後得以回收，更確保此技術之實用價值及符合綠色永續整治之理念。本研究將鎖定台灣常見之 Hg、Cu、Cr、Zn 及 Ni 為重點重金屬進行整治研究。 本期研究可分為三大部分。第一部分為將開發之材料進行水相吸附試驗，以了解各吸附材料對於重金屬之吸附能力，做為材料選用之依據。第二部分為利用上流式反應管柱組成之微型系統試驗，探討活性覆蓋層對於抑制多重重金屬之能力及穩定性。第三部分則為覆蓋材料之磁性回收效率試驗，以期能有效回收吸附污染物之覆蓋材料。最後本研究亦將比較傳統技術，討論此種可回收之吸附材料是否能更有效符合綠色及永續整治之宗旨。在比表面積方面，磁性生物炭以及硫化磁性生物炭的比表面積遠大於生物炭及硫化生物炭。從 XRD結果可以發現磁性生物炭以及硫化磁性生物炭皆有 Fe3O4 的晶相存在，而硫化磁性炭更發現 FeS 的晶相。水相吸附結果顯示四種生物炭對於鎳皆無效果，鉻、銅、鋅的吸附結果則呈現生物炭及硫化生物炭效果遠大於兩種磁性炭。在微型系統的實驗中發現四種生物炭皆能降低水中銅、汞、甲基汞的濃度，但只有硫化磁性炭能夠降低水中鎳及鋅的濃度，而所有生物炭對於鉻皆沒有抑制能力。在實驗的後期硫化炭以及磁性炭有一波汞的釋出，磁性炭以及硫化磁性炭也有著一波甲基汞的釋出。實驗的最後對於兩種帶有磁性的生物炭利用磁鐵進行回收，結果顯示在經過三個月的覆蓋後兩種材料仍能有效的被磁鐵吸引回收。本期研究之成果期望能克服活性覆蓋法在實場化過程之最後一哩挑戰，並期望能實現活性覆蓋法應用於重金屬底泥實場整治之終極目標。
計畫英文摘要	Accompanying decades of industrial activities is the consistent discharge of hazardous heavy metals into the natural habitats, posing urgent risks toward environmental and human health. Among all, mercury (Hg), chromium (Cr), zinc(Zn), nickel (Ni), lead (Pb), and arsenic (As) are eight primary heavy metals under deep concern throughout the globe due to their high biotoxicity. The remediation of natural sediment has been facing dramatic challenges in terms of technical and financial aspects. Disregarding the costly dredging technology, active capping is among the limited alternatives with real-site potential. With the progressive proof of active cappings' leaching inhibition of Hg, Cu, Cr, Zn, and Ni, our team's previous results have corroborated the feasibility of this technology. However, the concern for heavy metals' long-term stability has been continuously raised and ought to be overcome. For this reason, it is our primary goal in this proposed research to develop magnetic recoverable capping materials to allow the reclaim of the after-used materials, ensuring the technology's commercial value and sustainable virtue. This research will focus on the heavy metals Hg, Cu, Cr, Zn, and Ni for sediment remediation. The proposed research can be divided into three parts. The first part involves the aqueous batch experiments to determine the developed materials' sorption affinity to each heavy metal. The second part utilizes the up-flow reactors to perform microcosm experiments of which the materials' ability in heavy metal leaching inhibition would be evaluated. The third part is the materials recovery test, anticipated to obtain the valuable data for the feasibility of the materials to be reclaimed and reused. Also, the comparison of different technologies would be conducted to evaluate their compatibility with the "green and sustainable remediation" virtue. The materials’ synthesis and analysis results show that the specific area of magnetic biochar and sulfurized magnetic biochar is much higher than those of biochar and sulfurized biochar. The XRD results show the crystal of Fe3O4 in magnetic biochar and sulfurized magnetic biochar. The crystal of FeS is also found in sulfurized magnetic biochar. The batch adsorption experiments reveal that the four materials are not able to remove Ni. The removal efficiencies of biochar and sulfurized biochar toward Cr, Cu, and Zn are much higher than those for magnetic biochar and sulfurized magnetic biochar. In the microcosm experiment, all the materials were able to reduce the concentration of Hg, MeHg, and Cu. Only SMB could reduce the concentration of Ni and Zn. No amendments could effectively reduce the Cr concentration. In the later period of the microcosm, there were short Hg breakthroughs for SB and MB, and MeHg breakthroughs for MB and SMB. At the end of the microcosm, magnetic materials could be collected through commercial magnets successfully. This study's results are expected to overcome the last-mile challenges during the scaling-up process, achieving the ultimate goal of remediating heavy metalcontaminated sediment in actual sites.