景观湖水质的三维荧光指纹

荧光光谱法灵敏度高、选择性强、测量快速便捷,而三维荧光光谱更有信息丰富的优点。荧光光谱与水样具有一一对应的关系,就像水样指纹一样,被称为“水质荧光指纹”。 该文采用三维荧光光谱法研究了北京两个相邻景观湖四季的水质变化。两湖湖水均具有明显的类蛋白质和类腐殖酸的荧光,且类蛋白质的荧光强度较强。荧光强度与自然和人为活动的相关性表明,两湖湖水水质随季节变化明显,春夏季节水质相对较好,秋冬季节水质相对较差;以游船为主的娱乐湖的水质主要受藻类和植物生长等自然因素的影响,而种植等人为因素对植物观赏湖的水质的影响十分重要。由此可见,湖水水质的变化是由湖的功能决定的。在春秋人工清理藻类和植物的残余有利于保护湖体水质。

Fluorescence Properties of Lake Water

Fluorescence spectrum technique has advantages of high sensitivity, high selectivity and quick-and-easy detection, and excitation-emission matrix (EEM) can provide abundant information. Fluorescence spectrum is unique for each water sample and is named as “fluorescence fingerprint”. In the present paper, excitation-emission matrix was used to study the variability of water quality from spring to winter of two neighboring lakes in an urban park in Beijing. There was typical protein-like and humic-like fluorescence in the EEMs of the two lakes and the intensity of the protein-like fluorescence was significantly stronger. The close relationships between the fluorescence intensities and natural/anthropogenic activities showed that the water quality changed obviously with the season: the water quality in spring and summer was better than in autumn and winter. Natural factor like the growth of algae and plants etc was the major impact factor for the lake for pleasure boats, and anthropogenic factor such as planting was significantly important for the lake with ornamental plants. So the variability of water quality of lake is determined by the function of lake. To remove the remains of algae and plants in spring and autumn benefits the water quality of the lakes.