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年度	102	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	國立中央大學	申請系所	環境工程研究所
專案主持人	張木彬	職等/職稱	教授
專案中文名稱	同時處理土壤中戴奧辛、五氯酚及汞之整合性技術開發
中文關鍵字	裂解；戴奧辛；五氯酚；汞；整治技術
專案英文名稱	Integrated Approach for Simultaneous Removal of Dioxin, PCP and Mercury in Contaminated Soil
英文關鍵字	Pyrolysis；PCDD/Fs；PCP；Mercury；Remediation
執行金額
執行期間	2012/12/10 至 2013/12/9
計畫中文摘要	中石化安順場址不管是在污染物形態、污染物數量與污染物濃度均為國內外 罕見，受污染土壤中所存在之戴奧辛（PCDD/Fs）、五氯酚（PCP）與汞含量均遠 遠超過管制標準；而此種包含不同超高濃度毒性物質之複合式污染型態，是相當 棘手的污染整治場址。本研究以中石化安順場受污染土壤為對象，透過本研究團 隊使用自主研發之連續熱裂解模組暨空氣污染物防制設備，嘗試處理同時受高濃 度戴奧辛、五氯酚及汞污染之土壤。評估不同操作參數條件下，對戴奧辛、五氯 酚及汞之去除效率及回收效率進行系統性的評估。研究分二階段進行。第一階段 為實驗室批次熱裂解試驗，結果顯示污染土壤中戴奧辛及五氯酚的去除效率隨著 熱裂解模組操作溫度的提升而上升。在高於 600o C之操作溫度下，土壤中各污染物 之殘餘濃度皆符合法規標準。在連續熱裂解模組方面，則依實驗室批次試驗結果 為基礎，針對 500~750o C作為溫度測試參數。當處理量為 2 及 2.5 kg/hr（停留時間 分別為 33 及 26 分鐘），經 600o C處理後之土壤中戴奧辛及總汞濃度皆低於法規標 準（戴奧辛<1000 ng-TEQ/kg；汞<20 mg/kg）。空氣污染控制流程為袋式集塵器、 驟冷塔及流動床式活性碳吸附/熱解/再生系統去除排氣中之各種污染物。研究成果 顯示袋式集塵器可有效捕集粒狀污染物，集塵器出口氣流中粒狀物濃度皆低於 3 mg/Nm3 ；驟冷塔除冷凝水氣外，更可有效捕集氣流中之汞及其化合物，捕集效率 介於 80~90%之間，冷凝液中更可發現元素汞及部份硫化汞聚集。在流動床式活性 碳吸附塔方面，本計畫採用 3 層活性碳床，結果顯示排放之氣流中各污染物濃度 皆低於我國之排放標準（五氯酚 500 μg/Nm3 、戴奧辛 0.1 ng-TEQ/Nm3 、汞 50 μg/Nm3 ）。在質量平衡方面，將污染土壤輸入之污染物比率定義為 100%。因有機物（戴奧辛及五氯酚）可被高溫分解破壞，故計算後之戴奧辛及五氯酚總排放比 率（包含處理後土壤、集塵灰、放流水及排氣）分別低於 3.19%及 1.96%，顯示熱 裂解系統確實可將有機物破壞。汞僅會從污染土壤中脫附，但透過防制設備的有 效捕集，驟冷塔收集之汞比率達到 71.4%以上，系統之汞質量平衡介於 76%~84% 之間。經計算後，透過連續熱裂解系統暨空氣污染防制設備處理每公噸污染土壤 約消耗電力 2241.5 kWh，碳排放約 1201.5 kg-CO2，整治成本約NT 18,561 元 /ton-soil。
計畫英文摘要	In this case study, contaminated soil in An-shun site simultaneously contains extremely high concentrations of PCP, PCDD/F and mercury. Different characteristics of these contaminants have caused the difficulty of its effective remediation. For better remediation of contaminated soil in An-shun site, a continuous pyrolysis system is applied in this study. Before pilot-scale test, lab-scale batch tests are conducted to evaluate the effects of paramters including temperatures and additives. The results obtained from lab-scale tests indicated that removal efficiencies of contaminants are significantly increased with increasing operating temperatures. However, higher than 600o C may be needed to make sure that PCDD/F and mercury concentrations are lower than the limits, 1000 ng-TEQ/kg and 20 mg/kg, respectively. Based on the results obtained in lab-scale tests, operating temperatures of 500~750o C are applied in continuous pyrolysis system set in this study are tested for remediation of contaminated soil. However, higher than 600o C operating temperature in continuous pyrolysis system is still needed to effectively remove PCDD/Fs and mercury from contaminated soil as input rate of contaminated soil are controlled at 2 kg/hr and 2.5 kg/hr (retention times are 33 and 26 min, respectively.). In addition, high pollutant concentrations are found in flue gas of pyrolysis system outlet and baghouse, quench tower and multi-layer AC-adsorption bed as air pollution control devices are applied for effective emission control. Regarding particulate matter, lower than 3 mg/Nm3 of particulate matter concentration is obtained by baghous. Quench tower operating at 0~3o C can effectively removal mercury from flue gas. The removal efficiencies of mercury achieved withquench tower are higher than 80%. As for the multi-layer AC-adsorption bed, 3 layers are designed in this study. Finally, the emissions of contaminants including PCDD/Fs, PCP and mercury are stably controlled to meet the emission limits of three contaminants (PCDD/Fs: 0.1 ng-TEQ/Nm3 ; PCP: 500 μg/Nm3 ; Hg: 50 μg/Nm3 ). Furthermore, mass balances of PCDD/Fs, PCP and mercury are discussed in this study. Because organic pollutants can be destroyed with thermal condition, total discharge rates of PCDD/Fs and PCP including remediated soil, fly ash of baghouse, effluent of quench tower and emission of flue gas are lower than 3.19% and 1.96%, respectively. In contrast, mercury is just desorbed from contaminated soil. Fortunately, quench tower can effectively condense mercury vapor. Higher than 71.4% mercury compard with input mercury rate is recovered. The mass balance of mercury in continuous pyrolysis system and APCDs is between 76% and 84%. For continuous pyrolysis system and APCDs adopted in this study, energy consumption and CO2 emission are 2241.5 kWh/ton-soil and 1201.5 kg-CO2/ton-soil, respectively. Moreover, the cost of NT 18,561 is needed for remediating one ton contaminated soil of this site.