| 摘要: | 本研究群在先前已針對揮發性有機物自廢水中揮發的行為進行一系列之研究，由結果得知當溶解性大分子有機質或界面活性劑存在系統中時，會對其他有機物揮發造成抑制，但在研究過程中卻發現當系統中有醇類存在時，有機物的揮發速率會比沒有醇類存在時增加，特別是有風吹過液面時增加之情況更為明顯，此結果已偏離了預期之現象，本研究將以一系列的醇類添加及不同的氣相擾流條件來釐清醇類存在於溶液中對有機物揮發行為的影響機制。 本研究所使用之有機化合物為11種單環類的芳香族化合物，其具有相似的結構及相近的亨利常數值(0.085~0.395)，但卻有差異相當大的水溶解度(1780~0.56mg/L)，依其水溶解度的高低共分成三大類來進行實驗分析，而添加之醇類以乙醇及正庚醇為主，濃度為100 mg/L ~ 500 mg/L，氣相擾動條件則為0 m/s ~ 1.0 m/s。 由研究結果得知，推測正庚醇將有機污染物吸引至溶液界面之親和力遠大於乙醇，於靜置條件下乙醇確實會對有機污染物造成抑制作用，當加入氣相擾動條件後，風速增加至1.0 m/s時，才會造成有機污染物揮發量的增加；而正庚醇則有助於有機污染物的揮發，且添加微量風速(0.2 m/s)即可造成有機污染物之揮發量明顯上升。此外，亦得知低水溶解度化合物受風速條件之影響將大於高水溶解度之化合物；由所獲得之結果彙整後發現，有機污染物本身之物理化學特性除了亨利常數外，分子量及水溶解度為影響揮發速率最為顯著之因子。 Abstract Our previous researches have been conducted on a series studies for the volatilization behavior of volatile organic matters from the waste water. From the results, it has been shown presented that, when the dissolving macromolecular organic matter or surfactant presented in the system, the volatilization rate of organic matters show dramatically decrease. During the investigation, we have also found that, when alcohol is existing in the system, the volatilization rate of organic matters will increase as compare to the systems without alcohol. The phenomenon is more obvious especially when wind is blowing through the surface of the liquid. This research carried out a series of different gaseous phase conditions to evaluate the influence of alcohol on the volatilization behavior of organic matters. The selected compounds consist of 11 kinds of mono-aromatic hydrocarbon, with similar structure and Henry's constant value (0.085 to 0.395), but there is great difference of water solubility (1780 mg/L to 0.56 mg/L). We divided the compounds into three classes according with the level of water solubility during the experiment ranged. The alcohol adding is mainly ethanol and heptanol, the concentration ranged from 100 mg/L to 500 mg/L and gaseous phase turbulence changed from 0 m/s to 1.0 m/s. As the result, we could conclude that the ability of heptanol able to attract the organic pollution to the solution interface is much greater than that of ethanol. At still condition, the ethanol could truly cause the inhibition on the organic vaporization. However, under the condition of gaseous phase turbulence 1.0m/s, the organic volatilization is increased. Moreover, the heptanol could increase the organic compounds volatilization. The volatilization rate of the organic compounds would obviously be risen when the condition of micro-wind speed (0.2 m/s) is added in. In addition, we also found that the chemical compounds with low water solubility could be affected by the gaseous phase turbulence condition which is greater than that of compounds with high water solubility. Key word：Volatilization, alcohol, mass transfer coefficient (KOL), characteristic coefficient of interface ( αA) |
