都市垃圾焚化為國內廢棄物處理主要方式之一，惟焚化過程中可能生成多氯二聯苯戴奧辛與多氯聯苯呋喃（Polychlorinated dibenzo-p-dioxins and dibenzofurans， PCDD/Fs），對環境與人體健康造成潛在危害。活性碳噴注（Activated Carbon Injection， ACI）為焚化廠常用之 PCDD/Fs 控制技術，但其投加量與去除效果並非單純呈線性關係，過量使用亦可能增加操作成本與集塵灰產生量。因此，本研究以國內某採行觸媒濾袋（Catalytic Filter， CF）與選擇性觸媒還原系統（Selective Catalytic Reduction， SCR）之都市垃圾焚化廠為對象，探討不同活性碳噴注量對煙道排氣及灰樣中 PCDD/Fs 濃度、物種分佈與毒性貢獻之影響，並評估活性碳減量操作之可行性。本研究設定活性碳噴注量 8、4 及 0 kg/hr 三種操作條件，並同步分析煙道排氣、底渣、鍋爐灰、觸媒濾袋集塵灰及連續排放監測系統（Continuous Emission Monitoring System， CEMS）參數。結果顯示，煙道排氣 PCDD/Fs 質量濃度與國際毒性當量濃度（International Toxic Equivalent， I-TEQ）未隨活性碳噴注量增加而呈線性下降，而是呈現 8 kg/hr 最低、4 kg/hr 最高、0 kg/hr 居中之趨勢。於 8 kg/hr 條件下，煙道排氣總毒性當量濃度為 0.0202 ng I-TEQ/Nm3；4 kg/hr 條件下升高至 0.0747 ng I-TEQ/Nm3，且 CO 與 HCl 濃度分別達 47.2 ppm 及 18.0 ppm，顯示燃燒完全性較差且氣相氯源較充足，可能提高 PCDD/Fs 生成潛勢。灰樣結果顯示，鍋爐灰之 PCDD/Fs 質量與毒性當量濃度分別為 38.54–79.78 ng/g及 1.22–2.01 ng I-TEQ/g，明顯高於觸媒濾袋集塵灰之 4.40–10.41 ng/g及 0.15–0.39 ng I-TEQ/g，且兩者皆以編號 B之樣品最高，反映燃燒不完全及較高氯源可能促進 PCDD/Fs 於飛灰中生成與累積，而 CF 之觸媒作用則可能降低集塵灰中殘留濃度。未噴注活性碳條件下，煙道排氣總毒性當量濃度為 0.0507 ng I-TEQ/Nm3，雖高於 8 kg/hr，但仍低於 4 kg/hr，顯示 CF 與 SCR 系統正常操作時仍具一定控制能力。整體而言，三種操作條件之煙道排氣 PCDD/Fs 毒性當量濃度皆低於現行排放標準 0.1 ng I-TEQ/Nm3，表示在燃燒條件穩定且後端污染防制設備正常運作之前提下，活性碳噴注量具有減量可行性；惟減量操作仍須同步考量 CO、HCl、燃燒穩定性及污染防制設備效率。;Incineration is a mainstream technology for treating municipal waste in Taiwan; however， polychlorinated dibenzo-p-dioxins and dibenzofurans（PCDD/Fs）may be generated during incineration， posing potential risks to the environment and human health. Activated carbon injection（ACI）is commonly used to control PCDD/Fs emissions， but its dosage and removal efficiency do not follow a simple linear relationship， and excessive use may increase operating costs and CF ash generation. Therefore， this study investigated a municipal waste incinerator equipped with a catalytic filter（CF）and selective catalytic reduction （SCR） system to evaluate the effects of ACI rate on PCDD/Fs concentration， congener distributions， toxicity contributions， and the feasibility of reducing activated carbon usage. Three ACI dosages of 8， 4， and 0 kg/hr were tested. Stack gas， bottom ash， boiler ash， CF ash， and continuous emission monitoring system（CEMS）parameters were analyzed. The mass and international toxic equivalent（I-TEQ）concentrations of PCDD/Fs in stack gas did not decrease linearly with increasing ACI rate. The lowest concentration occurred at 8 kg/hr， the highest at 4 kg/hr， and an intermediate level at 0 kg/hr. The total toxic equivalent concentration was 0.0202 ng I-TEQ/Nm3 at 8 kg/hr and 0.0747 ng I-TEQ/Nm3 at 4 kg/hr. At 4 kg/hr， carbon monoxide（CO）and hydrogen chloride（HCl）concentrations reached 47.2 and 18.0 ppm， respectively， indicating poorer combustion completeness and a more abundant gaseous chlorine source， which may have enhanced PCDD/Fs formation. The PCDD/Fs mass and toxic equivalent concentrations in boiler ash were 38.54–79.78 ng/g and 1.22–2.01 ng I-TEQ/g， higher than those in CF ash at 4.40–10.41 ng/g and 0.15–0.39 ng I-TEQ/g. Both ash types had the highest concentrations in Sample B， suggesting that incomplete combustion and higher chlorine availability may promote PCDD/Fs formation and accumulation， while CF catalysis may reduce residual PCDD/Fs. Without ACI， the total toxic equivalent concentration was 0.0507 ng I-TEQ/Nm3， suggesting that the CF and SCR systems still provided PCDD/Fs control. Overall， all three conditions were below the current emission standard of 0.1 ng I-TEQ/Nm3， indicating that reducing ACI is feasible under stable combustion and proper operation of downstream air pollution control devices. However， CO， HCl， combustion stability， and control efficiency should also be considered.
