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年度	106	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	以不同熱處理技術應用多氯聯苯污染場址之可行性評估
中文關鍵字	超臨界水氧化技術, 戴奧辛, 多氯聯苯,熱解,修復
專案英文名稱	Evaluation of Thermal Processes for Remediating PCB – Contaminated Soil
英文關鍵字	Supercritical Water Oxidation (SCWO), PCDD/Fs, PCBs, Pyrolysis, Remediation
執行金額	1,000,000元
執行期間	2017/1/9 至 2017/11/30
計畫中文摘要	多氯聯苯（Polychlorinated Biphenyls, PCBs）屬持久性有機污染物（POPs），因氯原子取代位置和數量的不同共有209種同系物。由於其良好的阻燃性、低電導率、抗熱解能力和化學穩定性，曾被廣泛用於變壓器和電容器絕緣油、油墨添加劑、燃料分散劑以及農藥延效劑等。PCBs在使用過程中經由各種途徑進入土壤，造成土壤污染。PCBs在土壤中的分佈超過其進入環境總量的99％，在工業污染區的土壤中其含量可高達十幾個mg/kg。國內由於過去所使用的大型變壓器和電容器設備老化，出現不同程度的PCBs洩漏事件，給當地土壤帶來嚴重污染。由於PCBs具有高分子穩定性，低水溶性和高吸附特性，導致土壤基質中多氯聯苯的去除極其困難。本研究以典型電力電容器污染土壤為對象，透過本研究群自主研發的三種熱處理技術模組（熱脫附/氧化系統、熱裂解系統及超臨界流體氧化（SCWO）系統）進行比較，就不同操作參數條件（包含排氣組成、操作溫度、操作壓力及停留時間等）對PCBs及戴奧辛類化合物（dioxin-like compounds）之去除效率進行系統性的評估。本研究執行成果可提供國內受PCBs或dioxin污染土壤處理技術的新選擇。 實驗室批次熱裂解試驗結果顯示污染土壤中戴奧辛及PCBs的去除效率隨熱裂解模組操作溫度的提高而上升。操作於600oC，土壤中各污染物之殘餘濃度皆可符合法規標準。在超臨界流體氧化技術試驗結果方面，污染土壤中戴奧辛及PCBs的去除效率隨SCWO操作溫度、壓力、氧化劑濃度（H2O2)及反應時間的增加而提升。使用100%過剩氧量，反應溫度為380 oC，壓力為22MPa及停留時間為30分鐘條件下，對戴奧辛及PCBs的破壞效率皆可達99.9%以上，土壤中各污染物之殘餘濃度皆可符合法規標準。由於超臨界流系統可直接進行污染物破壞，使戴奧辛污染土壤整治技術達到低碳、低處理成本及低環境負荷的目標，故SCWO處理技術處理受戴奧辛及PCBs污染土壤符合最佳可行控制技術（BAT）及最佳環境實踐（BEP）之目標。
計畫英文摘要	Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants (POPs) and there are 209 PCB congeners as a function of chlorine numbers and chlorinated position. In recent years, the issue of PCB-contaminated soils has aroused wide public concern. PCBs are extremely hard to remove from soil matrix due to their high molecular stability, low solubility in water and high tendency to adsorb on particulate phase. In this study, super-critical water oxidation (SCWO) technology is self-developed for the remediation of soil contaminated with PCBs and dioxin-like compounds. For efficient contaminant removal, operating parameters including temperature, pressure, reaction time and oxidative additives ratio are tested. The fruitful results obtained in this study will support the novel technology for remediation of the PCB-contaminated soil. Before pilot-scale test, lab-scale batch tests are conducted to evaluate the effects of operating parameters including temperatures and additives on PCB destruction efficiency. The results obtained from lab-scale tests indicate that removal efficiencies of contaminants are significantly increased with increasing operating temperatures. However, operating the thermal treatment system at a temperature higher than 600oC may be needed to make sure that PCDD/F and PCBs concentrations are lower than the limits, i.e., 1000 ng-TEQ/kg and 0.09 mg/kg, respectively. Preliminary results for SCWO indicate that the removal efficiencies of PCDD/Fs and PCBs achieved increase with increasing operating temperatures, pressure, and the oxidant (H2O2) added. The destruction efficiencies of PCDD/Fs and PCBs achieved for the contaminated soil are more than 99.9% with 100% of stoichiometric demand, 380oC operating temperature, 22 MPa operating pressure and 30 min. retention time. The target pollutants in the remediated soil treated with above operating parameters of SCWO system meet the regulation of Taiwan EPA. SCWO designed in this study is a powerful and environment-friendly remediation technology for PCDD/F and PCB removal from the soil contaminated with PCBs or dioxin.