苯乙烯的三维荧光特性及水污染应急处理

苯乙烯对人体健康和自然环境具有极大的危害,是国际卫生组织确认的致癌物。历年来,苯乙烯泄漏事故频繁发生,对饮用水安全造成了极大的隐患。对水中苯乙烯污染进行快速监测并采取切实有效的应急处理措施有助于保障饮用水的卫生安全。利用三维荧光光谱技术对苯乙烯的水溶液进行分析,发现在Ex255/Em305处有一个明显的荧光峰,荧光峰值与苯乙烯溶液浓度呈现良好的线性相关,相关系数r达到了0.995 7,其颜色随浓度增加而变深。苯乙烯中共有4个共轭π键,其中苯环具有大的共轭π键结构,乙烯基上同样具有一个共轭π键。同时,苯乙烯的分子结构中,碳原子处于同一个平面上,属于平面构型且具有一定的刚性,符合强荧光物质所具有的特征。因此通过三维荧光扫描结合苯乙烯的荧光特性,能快速测定水体中苯乙烯浓度及判断水体的污染程度。粉末活性炭可以有效地吸附去除水中的苯乙烯。当苯乙烯在源水中的浓度达到《生活饮用水卫生标准》规定的限值0.02 mg·L~(-1)时,采用180目的粉末活性炭,投加量为15rng·L~(-1)时,苯乙烯浓度可降至0.001 mg·L~(-1),去除率达95.5%。

Study on the 3D Fluorescence Feature of Styrene and Emergent Treatment of Styrene Pollutant in Water

It has been acknowledged by WHO that styrene is a carcinogen which does great harm to human ’s health and natural environment .In recent years ,given the frequency of the leakage accidents of styrene that has given rise to potential safety hazard to drinking water ,the fast detection of styrene pollutant in water and treatment of accidental release are of great significance for supplying safe drinking water .Total scanning fluorescence technique was used to unravel the 3D fluorescence feature of styrene by scanning its aqueous solution .A distinct fluorescence peak of styrene located at Ex 255/Em305 was detected .There was a sig‐nificant linear correlation between the concentration of styrene and the value of fluorescence peak ,the correlation index being 0.995 7 .The color of the fluorescence peak got darker with the raise of styrene concentration .There were four conjugated doub‐le bonds existing in the structure of styrene ,among which a cyclic hydrocarbon with a continuous pi bond exists in benzene ring , the other one is in vinyl .All carbon atoms that makes up the structure of styrene were in the same plane ,thus styrene molecules were completely planar with certain rigidity ,which is the feature of fluorescent substances .Therefore ,the concentration of sty‐rene and the pollution of water by the leakage of styrene could be easily detected with the 3D fluorescence spectra .Powdered ac‐tivated carbon (PAC) had a good effect on the absorption of styrene dissolved in water .Adding PAC(180 mesh) at a dosage of 15 mg · L -1 into source water with the concentration of styrene was 0.02 mg · L -1 ,which is the limited value in sanitary standard for drinking water ,the concentration could be reduced to 0.001 mg · L-1 and the removal rate of styrene was as high as 95.5% .