Removal of organic impurities in an aqueous solution using UV irradiation produced from high and low pressure Hg lamps
Removal of organic impurities in an aqueous solution using UV irradiation produced from high and low pressure Hg lamps
复制标题
DOI：
10.1021/ie0611599
复制
发表时间：
2007-07-04
影响因子：
4.2
通讯作者：
Kim, Sangwook
中科院分区：
文献类型：
--
作者：
Kim, Taek-Soo;Kim, Jaewoo;Kim, Sangwook
使用过的回旋加速器靶水中所含的乙醇、甲醇、乙腈和丙酮等有机杂质应被去除，以便其可再次用作靶。在这项调查中，去除效率的水溶液中所含的有机杂质，使用紫外线照射诱导氧化在各种实验情况下进行了评估。使用具有185和254 nm的UV发射的低压汞灯（L-灯）和具有254 nm的UV发射的高压汞灯（H-灯）来照射与有机物质混合的水。石英UV吸收流动池位于反应器中靠近UV灯的位置，以使介质中的UV吸收剂量最大化。在大多数情况下，丙酮的分解速度最快，乙腈的分解速度最慢。为了确定波长，紫外吸收剂量，和催化反应对有机物的分解的影响，通过各种光谱手段，包括气相色谱法（GC），傅里叶变换红外光谱（FTIR），和紫外-可见光谱仪，根据实验方案观察到的中间物种的产生和有机分解的程度。借助于介质中溶解氧（DO）的催化反应，当与没有DO的催化反应的照射相比时，由L-灯UV照射产生的有机物和其它中间副产物如酸、丙酮和乙醛等的去除速度快约3倍。然而，对于H-灯照射，有机物的去除是非常缓慢的，中间酸没有被有效地去除，即使与DO。因此，在L灯紫外光照射下，在DO的帮助下，UV照射的有机物的总分解效率远高于H灯紫外光照射。
Organic impurities such as ethanol, methanol, acetonitrile, and acetone contained in a used cyclotron target water should be removed so it can be used as a target again. In this investigation, removal efficiency of the organic impurities contained in an aqueous solution using UV irradiation induced oxidation was evaluated under various experimental situations. A low pressure Hg lamp (L-lamp) with the UV emission of 185 and 254 nm and a high pressure Hg lamp (H-lamp) with the UV emission of 254 nm were used to irradiate the water mixed with the organic substances. A quartz UV absorption flow cell was situated closely to the UV lamp in the reactor maximizing the UV absorption dose in the medium. For most cases, the decomposition of acetone was the fastest while acetonitrile was decomposed the slowest. To determine the effects of the wavelength, the UV absorption dose, and the catalytic reaction on decomposition of the organics, generation of the intermediate species and the degrees of organic decompositions were observed by various spectroscopic means including gas chromatography (GC), Fourier transform infrared (FTIR), and UV-vis spectrometers depending on the experimental schemes. With the aid of the catalytic reaction of dissolved oxygen (DO) in the medium, the organics and the other intermediate byproducts such as acids, acetone, and acetaldehyde, etc. produced from the L-lamp UV irradiation were removed faster by about 3-fold when compared to the irradiation without the catalytic reaction of DO. For H-lamp irradiation, however, organic removal was very slow and intermediate acids were not removed efficiently even with DO. Overall decomposition efficiency of the UV irradiated organics under L-lamp UV irradiation with the aid of DO, as a result, was much higher than that with H-lamp UV irradiation.