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年度	112	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	國立高雄師範大學	申請系所	生物科技系(所)
專案主持人	陳士賢	職等/職稱	教授
專案中文名稱	大型石化污染場址污染土壤熱處理技術及效能評估(第二年)
中文關鍵字	熱增強型土壤氣體抽除技術, 高溫熱脫附法, 石油碳氫化合物污染場址
專案英文名稱	Evaluation of technology and performance of thermal treatment for petroleum contaminated soils in a large contaminated site
英文關鍵字	petroleum hydrocarbon contaminated soils, thermally-enhanced vapor extraction technology, thermal desorption, petroleum hydrocarbon contaminated site
執行金額	1,840,000元
執行期間	2023/9/1 至 2024/8/30
計畫中文摘要	熱脫附(thermal desorption)處理技術為土壤整治技術之一種，係利用加熱之方式將受有機物污染土壤加熱至有機物沸點以上，使吸附於土壤中之有機物揮發成氣態後再分離處理，此方式為物理分離程序，熱脫附處理技術已經驗證可應用於處理污染土壤、底泥、污泥及濾餅等。本計畫目的為配合國內大型石化場址整治，將國內較少使用之熱增強型土壤氣體抽除法及熱脫附法應用於離地處理石化污染土壤，評析熱增強型土壤氣體抽除技術(thermally-enhanced vapor extraction technology, TEVET)及熱脫附法(thermal desorption)，在不同油品、不同土壤質地、不同污染程度、及不同風化程度條件下對污染土壤之總石油碳氫化合物(Total petroleum hydrocarbon, TPH)移除效能。 第一年以建置及完備熱增強型土壤氣體抽除法及熱脫附法設施，以配合大型場址在第三區及第四區之快速整治進度，結果顯示由於TEVET操作處理三批次污染土壤之TPHg均相對低，不易彰顯其成效，柴油類總石油碳氫化合物TPHd之移除率成效不佳，因污染物沸點較高、蒸氣壓較低、揮發性較低之影響所致。多螺管式熱脫附系統在第一年執行期間，在三個整治區域共處理污染土壤23548公噸，污染土壤總石油碳氫化合物濃度範圍為2089 mg/kg至6820 mg/kg，TPH移除率介於84.1%至99.9%，第二年配合大型場址啟動第三階段整治工程，自2023年11月至2024年9月執行期間，多螺管式熱脫附系統共處理約33096公噸之污染土壤，污染土壤總石油碳氫化合物濃度範圍為529 mg/kg至9407 mg/kg，TPH移除率介於64.5%至99.5%，低移除率均屬原始污染土壤濃度值在1400 mg/kg及以下之批次，整體而言熱處理後之土壤，均符合操作單位及驗證單位(高雄市工務局)認定合格土壤之基本法規需求，即土壤TPH濃度需小於1000 mg/kg方能回填及再利用，多螺管式熱脫附系統設備經長時間操作，符合大型石化場址之污染土壤挖掘、不同工法離地復育、回填或再利用之快速整治方式。 檢核3-1區離地高溫熱脫附系統，污染土壤進料TPH濃度最高為9892 mg/kg，出料濃度介於113至197 mg/kg，平均每日操作量達115 B.M3(自然方)(約195公噸)，整治期間以熱處理進行污染改善土壤數量為14,731 B.M3(自然方)，約為18413.75 L.M3之鬆方(Loose cubic meter, L.M3)，約為27620公噸，整體處理效能符合預期。4-3及4-4區採熱脫附法處理之對象是污染土壤經清洗後產出的污染物富集土壤，土壤水洗過程中不可避免所產生之細粒徑殘留物，此類型土壤特性為進料時非常溼黏不易輸送，出料時則非常乾燥易引起大量揚塵，技術難度甚高，設備安裝及試車整改共歷時9個月，受限於專案完工期限，實際運作時間僅約70工作日(2022年12月至2023年2月)。全案累計處理20,200公噸濃縮污泥，每套平均處理量為10.5公噸/小時，略低於原設計之12公噸/小時。系統整體運作順暢，故障皆可在當日排除，開機率(有效運作)可達82.0%。進料濃度介於5,87036,800 mg/kg，平均值為14,700 mg/kg，典型的進料碳數分布以C12C22為主，屬柴油範圍。出料土壤每小時分堆檢測，出料濃度則介於24310 mg/kg，平均為82 mg/kg，TPH去除率達99.5 %以上。北二區(5-1區、5-2區、部分6-2區)污染土壤以旋轉窯熱處理方式進行，於2024年1月19日起開始雙線運轉，截至2024年5月28日設備結束操作止，總操作天數121天，累計處理量達114010公噸。共4套熱脫附爐進行土壤復育，其開機率(有效工時)可達90%，單日處理量平均可達975公噸，實際單爐產量為10公噸/小時/爐，高於原先規畫之設計量8公噸/小時/爐，實際處理量可高於設計處理量之原因，主要是進料污染土壤含水量比預期低。污染土進料濃度介於171910500 m/kg，平均值為3409 mg/kg，出料濃度則介於61328 mg/kg，平均為145 mg/kg，TPH去除率達96%，本熱脫附系統之所以能有高去除率，主要因加熱方式採直接加熱，窯內土壤受熱面積大，加上窯體轉動，土壤在窯內均勻混合，故脫附效果極佳，合格品佔比可達100%，能穩定產出高品質產品。 大型場址第一年共完成七個分區整治，其中有五個分區(3-1區、3-2區、3-3區、4-3區、及4-4區)污染土壤部分使用熱處理，熱處理設施溫室氣體總排放推估平均值為3072.8 t CO2-eq，熱處理設施溫室氣體總排放最高推估值為9049.3 t CO2-eq。第二年有二個分區(西區、北-2區)污染土壤部分使用熱處理，熱處理設施溫室氣體總排放推估為6865 t CO2-eq，熱處理設施溫室氣體總排放推估最高值為19614.1 t CO2-eq。綜合大型石化場址整治期間，所有個整治區其熱處理設施溫室氣體總排放之平均值推估為9937.7 t CO2-eq，推估熱處理設施溫室氣體總排放最高上限值為28393.4 t CO2-eq，此參數可供國內制定綠色及永續整治工法及擬定或盤查各整治工法碳足跡之參考。 高溫熱脫附處理其目的為移除污染物而盡可能保留原來土壤之物理性質及樣態，以便復育土壤可以回填場址及再利用。透過熱處理設施各單元階段溫度監控、土壤停留時間、螺管升溫條件、系統熱傳導均勻性、評估修正操作時間，尤其多螺管式熱脫附系統及旋轉窯系統在經過兩年以上多批次處理污染土壤，結果顯示符合大型場址整治需求，這些操作及維護經驗參數及碳排放資訊，可供場址熱處理法適用時機判斷依據，國內土壤及地下水整治界熱處理設施整廠輸出國外及系統操作維護及優化參考。
計畫英文摘要	Thermal desorption is suitable for the treatment of most volatile and semi-volatile organic pollutants in the soil, such as total petroleum hydrocarbon (TPH), chlorinated solvents, polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyl (PCB), dioxins, pentachlorophenol, and mercury. In addition to the application of various types of contaminants, thermal desorption has the advantages of short treatment cycle, high efficiency in removing contaminants, high safety, low cost, reusable soil and strong pollutant recovery capabilities. The method exhibits several advantages, such as short treatment period, high efficiency, high safety, lack of secondary pollution, and recycling of impacted matrices and contaminants. The basic process includes the heating (direct or indirect) of the contaminated environmental matrix at an appropriate temperature under vacuum or into carrier gas to separate target volatile/semivolatile contaminants from the media. During ex-situ thermal desorption, after the vaporization or sublimation processes, desorbed contaminants are condensed and consequently disposed in more concentrated volumes, activated carbon or thermal oxidizers are often used for off-gas treatment. Based on the boiling point of the target contaminants, thermal desorption can be classified as low temperature thermal desorption at the temperature range of 90-320C for volatile organic compounds (VOCs), or high temperature thermal desorption for semivolatile organic contaminants and metals at the temperature range of 320-540C. The objective of this study is to employ thermally-enhanced vapor extraction technology (TEVET) and thermal desorption to remediate the petroleum hydrocarbon contaminated soils in a 162-hectare contaminated site. TPH is a key evaluation indicator to establish target cleanup levels for petrochemical contaminated soil. Incorporating the remediation task of the mega size petroleum hydrocarbon contaminated site, the excavated soil will be rapidly screened to determine which method will be used for further treatment. If the concentration of TPH in soil is less than 3000 mg/kg with mainly gasoline range organics, TEVET will be used. If concentration of TPH is higher than 3000 mg/kg, thermal desorption will be used. If concentration of TPH is less than 3000 mg/kg but in diesel range organics, soil will be distributed to soil washing or bioremediation. If concentration of TPH is higher than 3000 mg/kg composing of diesel range organics, thermal desorption will be adopted. For the first-year study, TEVET was employed for three batches of 1000 tons soil treatment. The results indicated that gasoline range total petroleum hydrocarbon (TPHg) decreased ranging from 2.35 mg/kg to 182 mg/kg to below detection limit to 12.5 mg/kg. TPHg removal ranged from 90-92%. No apparent removal of TPHg was observed in weathered soils with apparent loss of VOCs. However, removal of diesel range total petroleum hydrocarbon (TPHd) in contaminated soil was between 7% to 57% due to contaminants were composed of compounds with higher carbon number and lower vapor pressure. Thermal desorption technology was performed in five remediated regions of the contaminated site by three types of thermal desorption systems in the first year. For System A, 23548 tons of TPH-contaminated soils were treated in operation of 152 batches in total. Concentrations of TPH contaminated soils ranged from 2089 mg/kg to 6820 mg/kg. Besides one set of treatment was below 80% TPH removal, the TPH removal ranged from 84.1% to 99.9%. For the second-year study, 33096 tons of TPH-contaminated soils were treated in operation of 1231 batches by System A. For System B, 23570 tons of TPH-contaminated soils were treated with average daily capacity of 190 tons. The highest concentration is 9892 mg/kg. Concentrations of treated soils ranged from 113 to 197 mg/kg. Overall the treated soils met the environmental regulation criteria with residual TPH concentration below 1000 mg/kg. Rotary kiln system was designed to treat 20,200 tons of TPH-concentrated sludge produced from soil washing facilities in System C in the first-year study. Only seventy days were operated in System C due to dust issue caused by dry-out of smaller size of concentrated sludges. The TPH concentrations of sludge ranged from 5870 to 36800 mg/kg due to the concentrated effect of soil washing. Concentration of treated sludge ranged from 24 mg/kg to 310 mg/kg. The average treatment capacity is 10.5 tons/hr. Rotary kiln system was adopted to treat 114010 tons of contaminated soils in the second-year study. The TPH concentrations of contaminated soils ranged from 1719 to 10500 mg/kg with average of 3409 mg/kg. Concentration of treated soil ranged from 61 mg/kg to 328 mg/kg. Total run time is 121 days. Total greenhouse gas (GHG) emissions from five different thermal desorption facilities was estimated to be 3072.8 to 9049.3 tons CO2-eq using average GHG of 0.07 ton CO2-eq/m3 associated with thermal desorption from previous study in the first year. GHG emissions was estimated to be 6869 to 19614 tons CO2-eq in the second year. Relevant information and obtained results in the mega contaminated site practice can be used as a basis line information for future scaling-up practice of hydrocarbon-contaminated soils remediated by ex-situ thermal desorption in Taiwan or remediation technology transfer to southeast Asia countries.