臺灣博碩士論文加值系統

　　本研究之目的在於建立煙道中重金屬成分之採樣方法，並探討重金屬成分鉛、鎘、鉻及汞於氣、固相之分佈。採樣時則使用US EPA Method 5，Method 12與Method 101A串聯的方式為參考方法，以採集都市垃圾焚化爐廢氣中之粒狀及氣狀重金屬成分；並於硝酸吸收液與粒狀物收集濾紙之間增加兩個冷凝用之空衝擊瓶以收集廢氣中之水分。而採集後之粒狀物則以超音波振盪法萃取並以石墨式原子吸收光譜儀分析鉛、鉻、鎘，而汞則以冷汞蒸汽法進行分析。
　　研究結果顯示，氣相成分Pb、Cr、Cd及Hg在串聯的各吸收液中之比例分別為冷凝液中是75.8、30.4、98.7與29.7％，0.1N硝酸吸收液中是24.2、6.2、1.3與0％，而在高錳酸鉀溶液則是0、63.5、0及70.3％，而造成冷凝水具有高收集效率的因素，則可能與水分經酸性氣體酸化或與金屬化合物之水溶性有關。並由冷凝液中的金屬成分與氯的關係得知，鉛可能以PbCl2的形式存在，而汞則是以水溶性的HgCl2為主要的成分；在鉛的氣固比與氯含量的關係可知，氯的含量能明顯的提高鉛的氣態含量。
　　在氣態含量上Pb、Cr、Cd及Hg在氣相中所佔的比例分別為4.2±2.2％、45±19％、4.2 ±4.0％及59±22％，因此Hg和Cr在氣相中所佔的比例較大，而Pb及Cd則是以固相的粒狀物型態存在為主。進一步推得Pb、Cr、Cd及Hg在氣相濃度與粒狀物中之分佈係數分別為0.011±0.012、0.13±0.07、0.018±0.02與0.35±0.23(μg/Nm3)/(μg/g)。

　　The purposes of this study are to establish the sampling method of heavy metals in flue gases. And the method was used to evaluate the partitions between gaseous and solid phases for Pb, Cd, Cr and Hg. U.S. EPA Method 5, Method 12 and Method 101A were adopted as the reference method. The sampling trains include two empty impinger to collect the Moisture, 0.1N HNO3 solution and KmnO4 solution in series. The sampling method was applied to the determination of particulate and gaseous metal emissions from municipal incinerators. The samples were analyzed for Pb, Cd and Cr by graphite furnace atmoic absorption spectroscopy (GFAAS) and for Hg by cold vapor atomic absorption spectroscopy (CVAAS).
　　The results showed that the ration of gaseous Pb, Cd, Cr and Hg were 75.8, 30.4, 98.7 and 29.7% in condensation water, the HNO3 absorbing solution collected 24.2, 6.2, 1.3 and 0%, and the acidic KmnO4 absorbing solution had 0, 63.5, 0 and 70.3%, respectively. The high absorbing efficiency in the condensation water may be due to acidic gaseous and soluble metallic components. Because high relationship was found between the metallic components and chloride in the condensation water, the Pb compositions was likely to be PbCl2, and the Hg compositions was high soluble HgCl2. Based on the relationship between the gas to particle ratio and chloride in flue gases, the Pb composition distributions in gas phase were increased with the chloride content.
　　In this study, the fraction of Pb, Cd, Cr and Hg composition distributions in gas phase were 4.2±2.2%, 45±19%, 4.2±4.0% and 59±22%, respectively. Thus, the Hg and Cr were mainly in gas phase, and Pb and Cd were almost in particle. In addition, the partition coefficients of Pb, Cr, Cd and Hg were 0.011±0.012, 0.13±0.07, 0.018±0.020 and 0.35±0.23 (μg/Nm3)/(μg/g), respectively.