Lü Wei-Wei, Yao Xin, Zhang Bao-Hua, Liu Yan-Long, Li Yuan-Peng
School of Environment and Planning, University of Liaocheng, Liaocheng 252000, China.
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
Huan Jing Ke Xue. 2018 May 8;39(5):2056-2066. doi: 10.13227/j.hjkx.201709278.
Thirty-two samples were collected from eight typical areas in Lake Taihu. Three-dimensional excitation-emission matrix fluorescence spectra (EEMs) and a parallel factor analysis (PARAFAC) were applied to investigate the fluorescence properties, the sources, and environmental significance of particulate organic matter (POM) from the overlying water in Lake Taihu in summer. Differences in fluorescence characteristics between POM and DOM (dissolved organic matter), and that in POM between the grass lake and the algal lake were further examined. There are five kinds of fluorophores in Lake Taihu:tyrosine-like fluorophores (C1 and C2), humic-like fluorophores (C3 and C4), and tryptophan-like fluorophores (C5), among which significant correlations were found between C1 and C2, C3 and C4, and C5 and two humic-like fluorophores (C4, C3). By comparing with the fluorescence characteristics of DOM from earlier studies, it is found that there are differences in compositions, sources, and correlations with water quality between POM and DOM in Lake Taihu in summer. In summer, the contribution of endogenous inputs to POM is greater than that of exogenous inputs in Lake Taihu because the ranges in the fluorescence indices, FI, BIX, and HIX, are 1.78-2.35, 0.3-2.7, and 0.8-1.1, respectively. Significant correlations have been found between humic-like fluorescent components and TN, TP, Chla, COD, POC, and SS, suggesting that fluorescence analysis can be used as an important method for a semi-quantitative analysis of nutrients. The protein-like components of the algal lake mainly consist of tryptophan and tyrosine, while that of the grass lake mainly contain tyrosine and a few tryptophan. It is worth noting that, the grass lake contains more tyrosine relative to the algal lake ( test, < 0.01). Significant positive correlations between the protein-like and the humic-like fluorescence are found in the algal lake, while it is not significant in the grass lake. Significant positive correlations are found between the fluorescent components (protein-like and humic-like) and chlorophyll-a in the algal lake, while the correlation was only found between humic-like components and chlorophyll-a in the grass lake.
从太湖八个典型区域采集了32个样本。运用三维激发-发射矩阵荧光光谱（EEMs）和平行因子分析（PARAFAC），研究了夏季太湖上覆水中颗粒有机物（POM）的荧光特性、来源及环境意义。进一步考察了POM与溶解有机物（DOM）之间荧光特征的差异，以及草型湖区和藻型湖区POM的差异。太湖中有五种荧光团：类酪氨酸荧光团（C1和C2）、类腐殖质荧光团（C3和C4）和类色氨酸荧光团（C5），其中C1与C2、C3与C4、C5与两种类腐殖质荧光团（C4、C3）之间存在显著相关性。通过与早期研究中DOM的荧光特征进行比较，发现夏季太湖POM与DOM在组成、来源以及与水质的相关性方面存在差异。夏季，太湖内源输入对POM的贡献大于外源输入，因为荧光指数FI、BIX和HIX的范围分别为1.78 - 2.35、0.3 - 2.7和0.8 - 1.1。类腐殖质荧光组分与TN、TP、Chla、COD、POC和SS之间存在显著相关性，表明荧光分析可作为营养物质半定量分析的重要方法。藻型湖区的类蛋白质组分主要由色氨酸和酪氨酸组成，而草型湖区的类蛋白质组分主要含有酪氨酸和少量色氨酸。值得注意的是，草型湖区相对于藻型湖区含有更多的酪氨酸（检验，P < 0.01）。藻型湖区类蛋白质荧光与类腐殖质荧光之间存在显著正相关，而在草型湖区则不显著。藻型湖区荧光组分（类蛋白质和类腐殖质）与叶绿素-a之间存在显著正相关，而草型湖区仅在类腐殖质组分与叶绿素-a之间存在相关性。
