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年度	106	專案性質	實驗性質
專案類別	模場試驗	研究主題	整治
申請機構	國立暨南國際大學	申請系所	土木工程學系
專案主持人	陳谷汎	職等/職稱	教授
專案中文名稱	環境友善型聚麩胺酸清洗受重金屬污染土壤之模場試驗
中文關鍵字	聚麩胺酸,重金屬,土壤清洗,綠色整治,土壤肥力,變性梯度膠體
專案英文名稱	A field pilot-scale study on heavy metal-contaminated soil washing by using an environmental friendly agent-polyglutamic acid
英文關鍵字	polyglutamic acid (PGA), heavy metal, soil washing, green remediation,soil fertility, denatured gradient gel electrophoresis
執行金額	1,800,000元
執行期間	2017/1/9 至 2017/11/30
計畫中文摘要	在台灣，土壤受到重金屬之污染已成為一嚴重之問題，尤其是農地的污染，往往導致其生產作物亦受到污染，對食品安全造成極大的威脅。本研究選擇一受中高濃度銅、鋅、鎳、鉻污染之農地，以氫型聚麩胺酸(polyglutamic acid, H-γ-PGA)清洗受重金屬污染之土壤。研究將先進行批次實驗，評估不同清洗條件對土壤重金屬移除之影響，再以最佳可行操作條件進行現地模場試驗，並做適度的參數調整，以提供現場整治之參考。本研究之主要目的為(1)評估不同操作參數(洗劑濃度、土水比、清洗時間等)對H-γ-PGA去除重金屬之影響；及(2)評估H-γ-PGA清洗對土壤性質及土壤肥力之影響。本場址面積為3,158 m2，本團隊以15 m × 15 m網格進行現地細密調查結果顯示，各項重金屬污染最高濃度分別為Cu：784 mg/kg、Cr：256 mg/kg、Zn：1,050 mg/kg及Ni：195 mg/kg，高污染區域集中於1892-19及1892-20兩靠近溝渠之點位，顯示該農地之污染可能來自溝渠。XRF分析結果與王水消化總量之間的相關性，結果發現對於銅、鉻、鋅及鎳的決定係數(R2)分別達0.9969、0.9972、0.9986及0.9943，未來進行現地整治時，可利用XRF分析，輔以本研究建立的公式迅速評估現地整治成效。PGA清洗土壤中Cr、Ni、Cu及Zn等金屬之試驗結果顯示，PGA對各種目標金屬皆有去除能力，PGA濃度升高，Cu、Cr、Zn及Ni去除效果亦增進。田口實驗結果顯示，不同操作因子對重金屬去除之影響為PGA濃度>水土比>清洗時間>轉速，最佳操作條件為PGA 3.5%、水/土比15/1、清洗時間60分鐘及轉速200 rpm。在此操作條件下，主要污染物Cu去除率最高可達50.7%。若以PGA清洗三次，Cu去除率可提升至74.3%。研究結果顯示，經PGA清洗後，各項重金屬濃度皆有下降，雖未低於管制標準，但對於超標倍數最高的銅已大幅降低其濃度，有助於翻轉稀釋法之成功率，毋需將高污染土壤外運處理。土壤經PGA清洗後，pH值接近中性、氮含量提高至114 mg/kg，且土壤菌相變化不大，顯示PGA相當具環境友善性。本研究成果，將可提供受污染場址進行整治之參考。 關鍵字:聚麩胺酸、重金屬、土壤清洗、綠色整治、土壤肥力
計畫英文摘要	In Taiwan, soil contaminated by heavy metals has become a serious problem. The contamination of agricultural lands results in the polluted produce, causing a great threat to food safety. In this study, a farmland contaminated by heavy metals (Cu, Zn, Ni, and Cr) was selected to evaluate the performance of H-type polyglutamic acid (H-γ-PGA) on the removal of heavy metals in soil washing. Batch experiments were conducted first to assess the effect of different washing conditions on the removal of heavy metals in laboratory. In situ pilot study will be then performed by using the optimum operating parameter obtained from the batch experiments. The main objectives of this study are to (1) evaluate the effect of different operating conditions (washing agent concentration, water/soil ratio, washing time) on the removal of heavy metals by H-γ-PGA; and (2) assess the effect of H-γ-PGA on the soil property and fertility. The area of the site was 3,158 m2 and soil sampling was conducted using a 15 m × 15 m grid soil sampling procedure. The results show that the highest heavy metal concentrations at this site were Cu: 784 mg/kg, Cr, 256 mg/kg, Zn：1,050 mg/kg, and Ni：195 mg/kg. The most seriously polluted area located at two sampling points near a trench, 1892-19 and 1892-20, indicating that water from the ditch may be the source of the heavy metals. The analytical results of soil between X-ray Fluorescence (XRF) and aqua regia digestion had a good relationship. Therefore, XRF analysis can be used during site remediation to evaluate the remedial performance in the future. The results of soil washing experiments show that PGA was capable of removing the target metals. The removal efficiency of heavy metals increased with increasing PGA concentrations. The results of Taguchi Method show that factors that affected the removal efficiency of heavy metals was of the order PGA concentration > water/soil ratio > washing time > rotational speed. The optimal operating parameters for heavy metal removal were: PGA 3.5%, water/soil ratio 15/1, washing time 60 min, and rotational speed 100 rpm. Under the optimal conditions, up to 50.7% of the major target metal, Cu was removed. When the soil was washed 3 times by PGA, the removal efficiency of Cu was improved to 74.3%. Although heavy metal concentrations in soil did not meet the soil control standards, Cu concentrations were reduced significantly. The washed soil could be further treated by the turn-over dilution method to achieve the success in remediation. Therefore, off-site treatment of soil was not needed. After the treatment, pH of soil was around neutral, total nitrogen content increased to 114 mg/kg, and the change in soil bacterial community was moderate, indicating that PGA is an environmental friendly washing reagent. The results of this study can provide valuable information for site remediation in the future. Keywords: polyglutamic acid (PGA); heavy metal; soil washing; green remediation; soil fertility