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年度	99	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	國立台北科技大學	申請系所	環境工程與管理研究所
專案主持人	席行正	職等/職稱	助理教授
專案中文名稱	熱脫附處理對土壤質地變化、汞與戴奧辛污染物去除效果以及物種分佈探討
中文關鍵字	熱脫附；汞；戴奧辛
專案英文名稱	Effects of thermal desorption on soil structures, removal effectiveness of mercury and dioxin contaminants, and repartitioning of speciation
英文關鍵字	Thermal desorption；Mercury；Dioxin
執行金額
執行期間	2010/12/29 至 2011/12/28
計畫中文摘要	本研究主要藉由中石化之熱脫附實驗室，以模廠級旋轉窯進 行土壤熱脫附實 驗。首先以實驗室熱重分析儀快速獲得數種受汞及戴奧辛污染土壤之失重行為， 藉由所得之熱重損失區段初步定義土壤受熱影響程度與可能操作之脫附條件(i.e., 較適脫附操作溫度)，之後將該條件配合不同之脫附溫度與延時，配合管柱實驗 獲取放大數據後，應用於旋轉窯反應器，以獲得於不同脫附條件下土壤質地變化 與土壤中汞與戴奧辛殘量變化情形。實驗測試包含四個土樣(以 A、B、D、E 代碼表示)於 500 或 550、700 及 800℃脫附處理之物化特性、汞與 PCDD/Fs 殘量 變化情形、汞型態分佈及戴奧辛物種分佈。結果顯示加熱後土壤 pH 皆由原本的 中性或弱鹼轉變為強鹼性，土壤中有機質含量隨加熱溫度升高而減少。所有土樣 中之汞(6.7–480 mg kg-1 )經 500℃持溫 0.5 小時模廠熱脫附條件下，濃度均可降低 至管制標準以下(i.e., 20 mg kg-1 )。PCDD/Fs 毒性當量經 500℃持溫 0.5 小時處理 後亦可低於管制標準(1000 ng I-TEQ kg-1 )。原始土壤中 PCDD/Fs 組成顯示， OCDD 及 OCDF 為主要化合物，熱脫附前與熱脫附後土壤中所含 PCDD/Fs 則 多以 PCDD 為主。汞之型態分佈顯示，熱脫附前與熱脫附後之型態分佈均以殘餘 態為主，顯示該場址之汞不論處理前後其生物可利用性均偏低。建議未來可測試 較低脫附溫度以節省能耗。考慮後續土壤再利用，亦可考量於明火條件下適度降 低熱脫附處理溫度。本研究促進瞭解污染物經熱處理後之再分配行為，期許所得 結果能做為未來實廠建構與熱脫附參數選擇之依據。
計畫英文摘要	This study examines the effectiveness of thermal desorption of CPDC’s contaminated soils using a bench-scale column reactor and a pilot-scale rotary reactor. The test parameters include desorption temperature, duration, and carrier gas flow rate. Thermogravimetric analysis (TGA) is used to preliminarily understand the thermal characteristics of soils. Four soil samples (A, B, D, E) contained various amounts of Hg and PCDD/Fs were then tested for their desorption properties at 500, 550, 700 and 800℃. The resulting physical and chemical properties and distribution of mercury fractionations and dioxin profiles were then accessed. The experimental results showed that the soil pH changed from neutral or weak basic into a strongly basic. Soil organic matter content decreased with elevating the desorption temperature. At all of the test temperatures, Hg concentration can be reduced to < 20 mg/kg, the soil standard by Taiwan EPA, from the concentrations between 6.7–480 mg kg-1 . The TEQ of PCDD/Fs at 500℃ for 0.5 hours after treatment reduced to < 1000 ng I-TEQ kg-1 . OCDD and OCDF were the major dioxin homologues in the soils, before and after thermal desorption. Mercury fractionation examinations showed that mercury was mainly in residual form before and after thermal desorption. These results suggested that the bioavailability of mercury in the contaminated site was relatively low. Considering reutilization of thermally treated soil, a lower desorption temperature can be tested on the targeting soilds to save energy under the direct-heating desorption operations.This study provided better comprehension in the repartitioning of these contaminants in soil. Results presented here may provide useful suggestions for the scale-up thermal treatment processes in the future.