EPA-100-1602-02-03

100

1,960 千元

2011/03/15

2011/12/31

劉希平

環檢所

黃星榜

輔仁大學公共衛生學系

環境監測及檢測

強極性;高水溶性;煙道等速採樣

strong polarity;high solubility;isokinetic stack sampling

鄭福田

劉耀仁

02-29053437#

037912@mail.fju.edu.tw

本計畫主要目的為評估與建立排放管道中丙烯醯胺（Acrylamide，AA）、己內醯胺（Caprolactam，CAP）、二甲基亞碸（Dimethyl Sulfoxide，DMSO）及二甲基甲醯胺（Dimethyl Formamide，DMF）等4種空氣污染物（本計畫合併簡稱為ACDD）之採樣與檢測技術，包括煙道排氣之採樣方式、樣本收集、ACDD儀器分析與樣本保存進行探討。本計畫以不同產業五場次（纖維、半導體、人造皮、樹脂I和樹脂II等工廠）之現場煙道檢測和檢驗品質管制/品質保證等措施，以確實驗證此方法可行性。計畫亦進行檢測技術擴散2場次，以達到技術檢討與轉移之效用。 由於ACDD具有高水溶性與高沸點之特性，多數工廠均採用洗滌設施處理相關廢氣，因此在洗滌設施除霧裝置操作不良狀況下，ACDD可能溶於水滴中，隨氣流排放。在進行煙道檢測過程中，採集氣態ACDD之同時，也不能忽略溶解排氣中含有ACDD之水滴，所以必須考量採集水滴等粒狀物之等速吸引採樣方式。然而，多數洗滌設施的入、出口管道多未能符合穩定氣流前提之採樣點之上游需有8倍直徑長度和下游2倍直徑長度之基本規範，所以也需評估若等速吸引採樣可否執行之代表性與正確性。本計畫採用同步進行（1）等速採樣與（2）不得破出最大採氣流量兩種採樣方式，以比較兩者之差異。經過五場次、七根次煙道排氣之實地檢測結果顯示，即使在煙流不穩定情形下，仍以等速採樣較佳。 ACDD樣本收集是以乙醇作為吸收溶劑，分為採樣管、前吸收瓶與後吸收瓶。現場採樣之結果顯示，約有20-30%DMF存留於採樣管中，因此樣本收集過程中，需以少量乙醇將採樣管內之ACDD洗出至前吸收瓶。在採氣量小於10 lpm前提下，前、後吸收瓶之比例則為樣本採集破出效率之管制程序（後吸收瓶不得超過前吸收瓶5%作為品質管制基準）。 分析方面則以GC/FID分析為主，並輔以GC/MS做可能有機物物種確認。GC分離管柱以分離極性化合物之60 m* 0.25 mm*1.2 um（膜厚）之 DB-624為主，在分流比3：1下，ACDD線性範圍在5-1000 ppm。檢測極限方面，在訊/雜比（Signal/noise ratio, S/N）為3情形下，儀器偵測極限為3 ppm， GC/MS之儀器檢測極限略高於GC/FID，約為5 ppm。樣本保存期限則在真實煙道氣體樣本中同時添加50 ug於7*1 mL樣本中，每天分析其樣本中ACDD濃度，樣本在4℃冷藏保存下之可保存長達7天，ACDD在樣本中之衰退情形並不明顯，顯示本方法之可行性。

強極性;高水溶性;煙道等速採樣

EPA-100-1602-02-03-Simple.pdf

3MB

2012/3/1 上午 12:00:00

The purposes of this project are to evaluate and establish a stack sampling and analysis method for high solubility and strong polarity chemicals such as acrylamide, caprolactam, dimethyl sulfoxide and dimethyl formamide (ACDD). The stack sampling and analysis method includes isokinetic sampling, sample collection, preservation and instrumental analysis. Through five different stack sampling programs at various factories, the stack sampling and analysis method was tested and verified its effectiveness and the quality control/quality assurance protocol. Technical transfer meetings were also held twice to encompass the thorough goal of this project. Because of the high solubility and strong polarity of ACDD, most factories applied scrubbers to clean up their exhaust gas, then emit through stacks. Upon stack sampling, not only particulate (mostly water droplets) phase but also gaseous phase should be thoroughly collected. Therefore, isokinetic sampling requirement is essential for ACDD in both particulate and gaseous phases. However, the physical characteristics of emission stacks after scrubbers are not suitable with upper stream 8D/ down stream 2D (D is the stack diameter) requirement for isokinetic sampling. According to laboratory and real stack sampling tests, about 20-30% of ACDD remaining in the sampling tube suggested isokinetic sampling is required to minimize the inertial loss of large particles in the flue gas stream. Ethanol in two sequential impingers is used to absorb ACDD during sampling. The sampling flowrate of 10 lpm was recommended as the upper limit to avoid possible breakthrough, which is defined as 5% of the second impinge to the first one. Gas Chromatography equipped with flame ionization detector (GC/FID) is used to analyze ACDD in this project. The chromatograph column is DB-624 with 60m, 0.25 mm I.d. and 1.4 um film thickness. With split ratio of 3:1 and carried gas linear velocity of 35 cm/sec, ACDD are well separated and quantified. The method detection limits of ACDD varied from 0.32 -0.88 ppm. Stored under refrigeration, ACDD can be preserved to seven days without significant deterioration.

strong polarity;high solubility;isokinetic stack sampling