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年度	104	專案性質	實驗性質
專案類別	研究專案	研究主題	底泥
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系統開發
中文關鍵字	戴奧辛,汞,五氯酚,底泥,整治技術
專案英文名稱	Integrated Approach for Simultaneous Removal of Dioxin, PCP and Mercury from Contaminated Soil (the 2nd stage)
英文關鍵字	PCDD/Fs, PCP, Mercury, Remediation
執行金額	1,400,000元
執行期間	2014/12/1 至 2015/11/30
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，是最難處理的污染整治場址。本研究於102~103年度已獲致初步成果，在第三年研究計畫中，本計畫分別以受中石化安順場址污染之海水池底泥及河川底泥為探討對象。結果指出處理海水池底泥時若操作溫度600oC且停留時間在46分鐘，可確保處理後底泥中戴奧辛/汞濃度可低於我國戴奧辛及汞之「底泥品質指標」之上限值（戴奧辛：68.2 ng-TEQ/kg；汞：0.87 mg/kg）。由於河川底泥之戴奧辛濃度約為海水池底泥的兩倍，處理後的河川底泥戴奧辛濃度若要低於「底泥品質指標」之上限值，則旋轉窯溫度在600oC條件下停留時間必需達62 分鐘。 排氣控制方面，高效袋式集塵器可有效去除粒狀物，集塵器出口粒狀物濃度可穩定保持在3 mg/Nm3以下；驟冷塔對戴奧辛及汞之去除效率皆隨冷凝溫度降低而提昇；流動床式活性碳吸附塔於0.5 cm/day之活性碳置換率下即可有效維持排放濃度符合法規標準，但因實際操作上，土壤濃度變動性高，故建議以1 cm/day為最佳之活性碳置換率。經過高效袋式集塵器、驟冷塔及流動床式活性碳吸附塔處理後，排氣中戴奧辛及汞濃度皆可低於我國最嚴格之排放標準（戴奧辛：0.1 ng-TEQ/Nm3；汞：50 μg/Nm3；SO2 <100 ppm）。本研究建立活性碳再生系統，採流動床式理念設計，活性碳吸附床中的球狀活性碳因重力往下移動至再生系統中，無氧條件下隨著反應時間增加，對戴奧辛及五氯酚的破壞效率愈高，對吸附於活性碳之戴奧辛及五氯酚的破壞效率可達98％以上，對於總汞可達99%以上的脫除效率，由於再生系統出口端含有高濃度的汞蒸氣，可將廢氣導回驟冷塔之入口端，藉由汞珠的回收將其去除，整個熱裂解系統中並無含汞廢棄物或汞污泥的產生，更能達到污染減量之目的。
計畫英文摘要	In this case study, contaminated sediment containing extremely high concentrations of PCP, PCDD/F and mercury in An-shun site is selected for remediation test. Different characteristics of these contaminants have caused the difficulty of its effective remediation. For better remediation of contaminated sediment in An-shun site, a continuous pyrolysis system (CPS) is designed and applied in this study. In 2013~2014, CPS had been proved for effective removal of PCDD/Fs and mercury from contaminated soil. In this stage of the project, contaminated sediments collected from sea-water ponds or channels of An-shun site are remediated with self-developed CPS. Regarding the sediment in sea-water ponds, PCDD/F and mercury in the sediment is efficiently removed with the operating temperature of 600oC and the retention time of 46 min., and the concentrations are lower than the limits of sediment quality index (PCDD/Fs: 68.2 ng-TEQ/kg; mercury: 0.87 mg/kg). As for the sediment in the river, the operating parameters with 600oC and 62 min. are needed to meet the limits set for sediment because PCDD/F concentration in the sediment of river is two times of that in the sediment of sea-water pond. Moreover, air pollution control devices (APCDs) including bag filter, quench tower and multi-layer adsorption system are tested simultaneously. Bag filter can effectively remove particulate matter (PM) and keep the PM concentration lower than 3 mg/Nm3 at bag filter outlet. Furthermore, removal efficiencies of PCDD/Fs and mercury achieved with the quench tower increase with decreasing operating temperature and multi-layer adsorption system (MAS) highly efficient to ensure that emission concentrations of PCDD/Fs and mercury are lower than the emission standards with AC replacing rate of 1 cm/day. However, SO2 is significantly found in the exhaust of CPS with the remediation of sediment. WS with NaOH as absorbent can efficiently remove more than 90% SO2 in the exhaust of the MAS. For continuous operation of MAS, a system for BACs’ regeneration is built with moving bed system. At oxygen-free condition (N2 as carrier gas), increasing retention time is beneficial to enhance destruction efficiencies of PCDD/Fs and PCP adsorbed on BACs (>98%) and removal efficiency of mercury adsorbed on BACs (>99%). Although vaporized mercury is discharged from the regeneration stream of BACs, exhaust of regeneration system is introduced into the flue gas before the quench tower and gaseous mercury can be efficiently recovered. Finally, the CPS applied in this study is demonstrated to efficiently remove PCDD/Fs, PCP and mercury from contaminated soil and APCDs applied can also effectively reduce the pollutant emission to meet the Standards. Furthermore, secondary pollutants including waste BACs and condensate from quench tower are not discharged from CPS+APCDs. Experimental results indicate that the CPS+APCDs developed in this study is a powerful and environment-friendly remediation technology for removing PCDD/Fs and mercury from contaminated soil and sediment.