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年度	112	專案性質	實驗性質
專案類別	研究專案	研究主題	自訂
申請機構	國立台灣大學	申請系所	生物環境系統工程學系
專案主持人	蔡瑞彬	職等/職稱	副教授
專案中文名稱	基於生物瀝取與深度學習之孔隙堵塞解決方案研究
中文關鍵字	孔隙堵塞與溶解,生物瀝取,現地化學氧化法,水力斷層掃描,卷積神經網路
專案英文名稱	Study on the solution for the dissolution of pore-clogging based on bioleaching and deep learning
英文關鍵字	pore-clogging and dissolution, bioleaching, in-situ chemical oxidation, hydraulic tomography, convolutional neural network
執行金額	1,084,000元
執行期間	2024/1/1 至 2024/12/31
計畫中文摘要	現地化學氧化法是處理土壤與地下水有機污染物的常用方法之一，但整治過程中常遭遇孔隙堵塞問題，導致藥劑傳輸受阻，進而降低整治效果。為探討此問題並提出可行解決方案，本研究利用砂箱試驗模擬現地化學氧化（ISCO）整治工程，重現孔隙堵塞現象，並通過有機酸灌注促進生物瀝取機制去除沉澱物。本研究選用芬頓試劑作為ISCO藥劑，檸檬酸作為有機酸。透過時序水力掃描（Time-lapsed Hydraulic Tomography, TLHT），本研究評估了孔隙介質在沉澱物生成與移除過程中的透水性變化，並模擬相應的流場變化，以量化孔隙堵塞與溶解對地下水參數和流場的影響。砂箱中的鐵離子變化由分光光度計測量溶解態鐵含量，沉澱態鐵含量則通過ICP-OES測量，而微生物總量則透過DNA萃取進行測定。研究結果顯示，TLHT成功量化了芬頓試劑灌注後的孔隙堵塞效應，以及檸檬酸溶解沉澱物對水力傳導係數（K值）的影響。K值與土壤鐵沉澱物濃度呈線性關係，因此TLHT可作為量化孔隙堵塞的重要工具。研究成果顯示，未添加檸檬酸的組別，K值平均變化小於2%，添加一倍當量檸檬酸組別K場平均上升11.43%、添加五倍檸檬酸組別K場平均上升13.21%。由水體總鐵濃度可知，添加檸檬酸組別的平均值51.48 ppm，是未添加檸檬酸組8.50ppm的6倍，顯示檸檬酸能促使砂箱中的砂體溶出鐵至水中。另外由DNA濃度萃取結果可知，塞階段DNA的平均濃度為0.73ng/μl、而溶解階段的平均濃度為2.86ng/μl，DNA核酸的濃度增加至3.92倍。研究結果證實，TLHT可量化整治場址的三維透水性演變，並證明生物瀝取在溶解鐵沉澱物方面的有效性，提供了一種創新且具有參考價值的解決方案。最後，本研究建議可以修正型芬頓試劑的濃度為參考，取一倍當量的檸檬酸施行生物瀝取，可去除大部分的三價鐵孔隙堵塞。
計畫英文摘要	In-situ chemical oxidation (ISCO) is one of the common methods for treating organic contaminants in soil and groundwater. However, pore-clogging during the remediation process often obstructs reagent transport, reducing the overall treatment effectiveness. To investigate this issue and propose viable solutions, this study utilized sandbox experiments to simulate ISCO remediation projects, recreating the phenomenon of pore clogging. Organic acid flushing was employed to promote a bioleaching mechanism for precipitate removal. Fenton’s reagent was used as the ISCO reagent, and citric acid was selected as the organic acid. Through Time-lapsed Hydraulic Tomography (TLHT), this study assessed the permeability changes of the porous medium during the formation and removal of precipitates. It simulated the corresponding flow field changes to quantify the effects of pore-clogging and dissolution on groundwater parameters and the flow field. Iron content in the sandbox was measured using spectrophotometry for dissolved iron and ICP-OES for precipitated iron, while total microbial content was determined through DNA extraction. The results showed that TLHT successfully quantified the pore-clogging effects after Fenton reagent injection and the impact of citric acid on precipitate dissolution and hydraulic conductivity (K values). A linear relationship was found between K values and soil iron precipitate concentrations, demonstrating that TLHT is an essential tool for quantifying pore clogging. The study also revealed that in the group without citric acid, the average change in K values was less than 2%, while the K field increased by 11.43% in the group with a one-equivalent dose of citric acid and by 13.21% in the group with a five-equivalent dose. The total iron concentration in water was 51.48 ppm in the citric acid group, six times higher than the 8.50 ppm in the non-citric acid group, indicating that citric acid facilitated iron dissolution from the sand. Additionally, DNA extraction results showed an average DNA concentration of 0.73 ng/μl during the clogging stage and 2.86 ng/μl during the dissolution stage, representing a 3.92-fold increase. These findings confirm that TLHT can quantify the three-dimensional permeability evolution at remediation sites and demonstrate the effectiveness of bioleaching in dissolving iron precipitates, offering an innovative and valuable reference solution.