辽河流域与英国中部河湖水体中溶解有机质的荧光特性

运用三维荧光光谱技术对辽河流域和英国中部水体中溶解有机质(DOM)的荧光光谱特性进行了分析.结果表明,辽河流域各研究水体中DOM包含4种荧光组分,即类色氨酸、类酪氨酸、可见光区和紫外光区类腐殖质,通过对荧光特性定量指标的分析可知,辽河流域各研究断面水体中类腐殖质物质内源作用大于陆源,DOM具有较强的新近自生源,各河流水体中DOM腐殖化程度顺序为:浑河中游海城河中游蒲河下游太子河下游.相比之下,英国河湖中,除了River Tame含有以上4种荧光组分外,其它水体中均没有发现类酪氨酸荧光物质,甚至在River Tern中仅含有类腐殖质荧光物质,河湖中DOM含有较少的新近自生源组分,以陆源影响为主.另外,辽河流域水体中类蛋白与类腐殖质荧光峰强度比值大于英国各河流水体的平均值.由此可以推断,辽河流域各研究断面大量污染物的输入,是造成其严重内源污染的主要原因,从而使水体中DOM含量增加,英国各河流断面其DOM主要来自于水体本身存在的大量微生物和浮游植物的代谢活动以及土壤有机质经雨水的冲刷流入水体的贡献.

Fluorescence characteristics of dissolved organic matter in freshwaters from Liaohe Basin and Midland of UK

Three-dimension excitation-emission matrix fluorescence spectroscopy was used for the characterization of dissolved organic matter (DOM) in the freshwaters from Liaohe Basin and Midland of UK. The results showed that the tryptophan-, tyrosine-, fuvic-and humic-like materials were present in the waters of each sampling site from Liaohe Basin. The calculated fluorescence parameters for all sampling sites indicated that humic-like components of riverine DOM were mainly originated from autochthonous source and the contents of immature microbially-derived DOM in Taizihe, Hunhe, Haichenghe were higher. The order of the decrease in the humification level was Hunhe > Haichenghe >Puhe > Taizihe. Comparatively, except for the River Tame in the Midland of UK which included the above four fluorescence materials, the Vale Lake and River Cole consisted of tryptophan-, fuvic-and humic-like materials and only fuvic-and humic-like substances were present in the River Tern. The humic-like components of riverine DOM were mainly derived from terrestrial organic matter. Additionally, the average fluorescence intensity ratio of protein-to humic-like substances for Liaohe Basin was higher than that of UK freshwaters. Therefore, the discharge of anthropogenic pollutants into the rivers resulted in the endogenous pollution, which substantially contributed to DOM content in Liaohe Basin, while the DOM in freshwaters of UK was from both soil-derived and aquatic/microbial-derived origin.