EPA-111-FA13-03-A084

111

14,110 千元

固定污染源管制

2022/01/06

2022/12/15

羅鈞

空保處

林怡君

環興科技股份有限公司

大氣空氣

戴奧辛、重金屬、大氣環境檢測、輔導減量

Dioxin, Heavy Metals, Environmental Monitoring, Emission Reduction

陳秉圻

02-27691366#20863

bcchen@mail.sinotech-eng.com

本計畫主要工作內容包括：(1)執行大氣環境中之戴奧辛及重金屬檢測作業、(2)更新及建置戴奧辛及重金屬排放清冊、(3)水泥窯排放特性調查、(4)協助辦理公私場所固定污染源之戴奧辛及重金屬排放減量輔導、污染事件緊急應變等相關行政作業。 本計畫大氣環境中之戴奧辛及重金屬空品監測作業於2及8月完成採樣，22監測站2次戴奧辛監測濃度平均值分別為0.021 、0.015 pg I-TEQ/m³ (0.019、0.015 pg WHO-TEQ/m³)，戴奧辛多氯聯苯則為0.0016、0.0015 pg WHO-TEQ/m³，均低於歷年同期之監測結果平均值，尤其本年度2月因降雨天數較多，故戴奧辛濃度明顯較低。以空品區分析，8月各空品區的濃度差異性較小，2月以雲嘉南空品區濃度較高，宜蘭和花東空品區較低；嘉義測站2月濃度值雖屬正常範圍，但與其他測站監測結果相比略偏高，應是受監測期間測站附近火災影響。重金屬部分，一般空品站之有害重金屬類監測結果均符合我國及歐盟之環境空品基準值，各項重金屬以地殼類元素(例如：鋁、鐵)濃度較高，2月及8月22項重金屬(包含地殼類元素)質量濃度占PM₁₀比例範圍為1.19%~33.3% (中位數2.72%)，大氣環境中有害重金屬空品濃度相對較低，其中以鉛(Pb)濃度較高。 排放清冊更新部分，民國110年國內戴奧辛排放量推估結果約為43.07 g I-TEQ/年，低於民國109年，排放量減低的主因為露天燃燒活動強度更新為TEDS11的燃燒比例資料而下降，主要的固定排放源包含：電力能源產源之鍋爐、鋼鐵冶煉業(燒結爐、電弧爐) 及廢棄物焚化爐為主，占整體排放量61.8%，109年超標之電弧爐業者在110年的平均排放濃度較低，導致該業別排放係數下降。重金屬部分，110年重金屬排放量推估結果分別為鉛(Pb) 29.8公噸/年、鎘(Cd) 0.728公噸/年、汞(Hg) 1.68公噸/年及砷(As) 2.67公噸/年，與109年差異不大，因面源在對重金屬排放量占比較低，受其活動強度變化影響小。 水泥窯氟(F)檢測結果顯示，水泥窯氟(F)排放濃度均在1mg/Nm³以下，符合歐盟現行最嚴格標準，每座水泥旋窯的校正排放濃度(以含氧率10%為參考基準)差異不大，排放濃度較低的原因為水泥製程中所產生的氟化物熔點較高，多數經由熟料離開製程系統；水泥窯汞檢測濃度約在20 μg/Nm³~50 μg/Nm³之間，部分近期開始使用燃煤電廠飛灰的水泥窯排放濃度較高，同時集塵設備的種類與操作條件亦為影響排放濃度的因子之一。 針對燒結爐、集塵灰高溫冶煉設施、火化場及燃材及其他燃料鍋爐等戴奧辛重金屬主要排放源或超標潛勢較高業者進行10場次排放減量輔導會議，目前國內煉鋼業燒結爐僅有2家業者共6座，空污防制設備均完善，但L1燒結爐因飛灰的再投入使其進料氯含量上升，導致戴奧辛排放濃度近年呈上升趨勢，2家業者燒結爐均採用觸媒分解戴奧辛技術，觸媒歷年均有針對其脫硝效率檢驗但戴奧辛分解效率則沒有定期檢驗，建議須加強檢視以確保長期處理效率；本年度針對2座排放濃度較高的集塵灰高溫冶煉設施進行輔導，其中一家業者因使用醫療廢棄物為原料，使其近期戴奧辛排放濃度超標，分析其粒狀物和戴奧辛排放濃度均有升高趨勢，建議針對粒狀物的去除進行改善，同時該排放源排氣溫度跳動幅度較大，適當的溫度區間為戴奧辛再合成的必要條件之一，建議新增急冷設備；燃材及其他燃料鍋爐為國內易超標排放業別，本年度輔導3座燃材及其他燃料鍋爐，其中一家規模較大的汽電共生業者使用較大量的RDF為燃料，與燃煤鍋爐相比有較高的超標潛勢，該廠檢測數據含氧率跳動幅度較大，助燃物的多寡會影響燃燒狀況，建議針對相關操作參數執行改善，該廠的廢棄物再利用規劃相當完善，另外2家規模較小的燃材鍋爐業者均有粒狀物排放濃度較高的疑慮，粒狀戴奧辛排放濃度可能較高，建議針對集塵器加強維護；另2座火化場近年有較高的戴奧辛排放濃度值，其中1座火化場其針對戴奧辛的空污防制設備較不完善，但該場針對排放溫度及燃燒溫度進行控制，故目前該場尚無超標紀錄，另1座火化場使用觸媒降解戴奧辛，但該場排放溫度偏低，有操作條件是否符合觸媒設計值之疑慮。 規劃及檢討修訂排放管制標準部分，主要在於協助辦理「鋼鐵業燒結工場戴奧辛管制及排放標準」、「鋼鐵業集塵灰高溫冶煉設施戴奧辛管制及排放標準」及「鋼鐵業燒結工場空氣污染物排放標準」研修工作。已完成燒結工場、鋼鐵業集塵灰高溫冶煉設施排放現況分析，建議將二者戴奧辛既存標準與新設排放標準一致，並將「鋼鐵業燒結工場戴奧辛管制及排放標準」與「鋼鐵業燒結工場空氣污染物排放標準」合併以簡化法規，現已協助完成修正草案研擬。

戴奧辛、重金屬、大氣環境檢測、輔導減量

EPA-111-FA13-03-A084.pdf

18MB

成果報告

2024/1/25 上午 12:00:00

The scope of this project includes: (1) monitoring of dioxins and heavy metals ambient air concentration (2) establishing and updating both dioxin and heavy metals domestic emission inventory (3) assisting the emission control, emission reduction and emergency response regarding dioxins and heavy metals which includes reconsideration and modification of emission standards The ambient air dioxins and heavy metal were measured in February and August this year. The average concentration of dioxins in 21 counties and cities were 0.021 and 0.015 pg I-TEQ/m³ (dioxins: 0.020 and 0.015 pg WHO₂₀₀₅-TEQ/m³, polychlorinated biphenyl (PCB): 0.0016 and 0.0015 pg WHO₂₀₀₅-TEQ/m³) respectively. The average concentrations were lower than the average value of the monitoring results in the same period of the previous years. The ambient air concentrations of hazardous heavy metals obtained in general air quality monitoring stations were lower than the air quality standards of Taiwan, European Union and WHO. The concentration of heavy metals which were relatively abundant in crust were higher than the other metal elements. The total mass concentrations of 22 analyzed heavy metals accounted for about 2.72% of PM₁₀ concentration. The total dioxins emission quantity was estimated to be 43.07 g I-TEQ/year in 2021, significantly lower than that in 2020. The reduction was mainly caused by the lower agricultural open burning amount in 2021 according to Taiwan Emission Data System version 11.1 (TEDS 11.1). The main dioxin stantionary emission sources consist of coal-fired power plants, steel melting industries and incinerators. The main sources mentioned accounted for 61.8% of the total emission. As for the heavy metal, the emission amount of lead, cadmium, mercury and arsenic was 29.8, 0.728, 1.68 and 2.67 tons respectively in 2021. The emission amounts were similar to that in 2020. In respect of uncertainty analysis and emission level classification, the emission data for stationary source was calculated based on actual emission tests and database from air pollution fee which could demonstrate a better reliability. In contrast, due to the lack of test data, the estimated emission amount of fugitive sources and mobile sources had lower reliability. Fluorine emission concentrations of 6 tested cement kilns were similar. The stack test results were all under 1mg/Nm³. According to studies, the high melting point of the fluoride compound in the manufacturing process led to a larger mass proportion of the substance leaving the system in clinker. The mercury emission concentration of the tested cement kilns ranged for 20 to 50μg/Nm³. The factor causing a higher emission concentration included the type and operation paramters of dedust device and the usage of substitute raw material such as fly ash from coal power plants. A total of 10 plants of emission reduction counseling were included in this project. This part of work aimed to assist emission sources with emission reduction by the advices given by experts. The imformation gathered in these counseling meeting could be used as a reference for future emission standards revision. Among the counseled emission sources, one of the visted cremation furnaces had no air pollution controlling device specificly targeting on dioxin removal. However, through appropriate burning temperature control, the emission source has never exceeded dioxin emission limit. Experts advised that the frequency of bag filter exchanging should be controlled rather than replacing it only if damaged bags was noticed to prevent the potential probability of violating the emission standards. Another cremation furnaces adopted catalyst for dioxin removal but the operation temperature was not enough for catalystic degradation. The visited Refuse-derived fuel (RDF) boiler had an unstable oxygen content in its flue gas according to it stack tests. The oxygen content was crucial for complete combustion to avoid the fabrication of dioxin. Thus, a more stable operation condition was needed for the emission source to lower its dioxin emission. Both of the 2 visited wood boilers had a high particle matter emission. The high dioxin concentration value in their stack tests report might caused by the dioxin adsorbed on particles. Thus, strengthening the maintaince of its bag filter could be an appropriate approach to prevent high dioxin emission. Both of the 2 visited steelmaking sinters had complete series of APCD. However, one of them return the fly ash back to sinter without any pretreatment. This might cause chloride acummulation in the system which lead to potential increase of dioxin emission concentration. Both of the 2 visited fly ash smelting furnaces adopted bag filter as its APCD. One of them recently had dioxin emission concentration violating the emission standard. Due to the positive correlation of its particle and dioxin emission, experts recommended enhancing the maintenance of its particulate matter capturing device. By reconsidering and reviewing of emission control standards, the revised emission standards steelmaking sinter and fly ash smelting furnace were proposed. More stringent dioxin emission standards for the emission sources mentioned above will be applied to existing sources in the draft recommendation.

Dioxin, Heavy Metals, Environmental Monitoring, Emission Reduction