黄石市磁湖水体溶解性有机物的时空分布特征

Temporal and Spatial Distribution Characteristics of Dissolved Organic Matter in Cihu Lake of Huangshi City

利用三维荧光光谱技术(EEMs)结合平行因子分析法(PARAFAC)研究了磁湖水体溶解性有机物(DOM)的时空分布特征及其来源,以期为城市富营养化湖泊的治理提供参考。结果表明:(1)磁湖水体DOM主要由陆源类腐殖质组分C1(340/430 nm)、不明腐殖质组分C2(390/480 nm)、类蛋白物质组分C3(290/350 nm)以及自生源类色氨酸组分C4(280/330 nm)这4种荧光组分组成。其中C1对磁湖DOM的贡献最大,C4最小。(2)4种组分存在时空差异,各组分最大荧光值(F max)在夏秋季较高,冬春季较低,其中组分C1变化最明显,C3次之;在空间分布上,靠近居民区的湖区F max值较高,反之较低,组分C1变化最明显。(3)磁湖水体DOM的组成成分主要来源于各类腐殖质,其次为微生物降解的内源类蛋白物质。(4)组分C1、C2、C3呈显著正相关性,表明它们具有同源性。(5)吸收系数a 350与叶绿素a(Chl-a)浓度呈极显著正相关性,表明磁湖水体DOM的荧光吸收与浮游植物密切相关。

Three-dimensional fluorescence spectrum technology(EEMs)and parallel factor analysis(PARAFAC)were applied to study the space-time distribution characteristics and sources of the dissolved organic matter(DOM)in water of Cihu Lake,in order to provide references for the treatment of urban eutrophic lakes.The results show that in Cihu Lake,DOM mainly consisted of terrestrial humic-like component C1(340/430 nm),unknown humic-like component C2(390/480 nm),protein-like component C3(290/350 nm)and the self-generated tryptophan component C4(280/330 nm).Among them,C1 was the largest contribution to DOM of Cihu Lake,and C4 was the smallest.There were temporal and spatial differences between the four components of the Cihu Lake.The maximum fluorescence value(F max)of each component was higher in summer and autumn,lower in winter and spring.The most obvious component was C1,followed by C3.In terms of spatial distribution,the F max value was higher in the area which was close to residential areas,and component C1 changed most obviously.(3)The components of DOM in Cihu Lake was mainly derived from different kinds of humus,followed by endogenous protein-like substances degraded by microorganisms.(4)There was a significant positive correlation between components C1,C2 and C3 in Cihu Lake,which indicate that they had homology.(5)It showed a strong positive correlation with Chl-a conceatration in the absorption coefficient of a 350,which indicate that the fluorescence absorption property of DOM was closely related to phytoplankton.