Dynamics and characteristics of fluorescent dissolved organic matter in the groundwater, river and lake water
Dynamics and characteristics of fluorescent dissolved organic matter in the groundwater, river and lake water
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DOI：
10.1007/s11270-007-9405-1
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发表时间：
2007-09-01
影响因子：
2.9
通讯作者：
Tanoue, Eiichiro
中科院分区：
文献类型：
--
作者：
Mostofa, Khan M. G.;Yoshioka, Takahito;Tanoue, Eiichiro
采用三维激发发射矩阵（EEM）技术，测定浅层地下水、河流和湖泊水体中的溶解有机碳（DOC）、无机阴离子和电导率（EC），研究了地下水-河流-湖泊环境中的荧光溶解有机质（FDOM）。地下水（16 ~ 328亩mc，平均109 +/- 88亩mc）、河流水体（43 ~ 271亩mc，平均158 +/- 62亩mc） DOC浓度较高且变化较大，碧洼湖水体（89 ~ 97亩mc，平均93 +/- 2亩mc） DOC浓度极低。EEM的荧光性质表明，地下水和河流水体中以黄颡鱼类成分（C峰、A峰和M峰）为主，而湖泊水体中以蛋白质样成分（T峰）为主。Ex/Em的C峰在地下水中为320 +/- 9/424 +/- 5 nm，河流中为340 +/- 5/ 432 +/- 4 nm，湖泊水体中有两个峰，分别为347 +/- 7/441 +/- 11 nm （C峰）和304 +/- 2/421 +/- 8 nm （M峰）。从地下水到河流再到湖泊，T峰发射波长逐渐缩短。琵琶湖中部水体的T峰波长为279 +/- 2/338 +/- 11 nm，较湖岸的283 +/- 3/350 +/- 7 nm短。上游水体的光照射实验表明，湖泊水体中黄腐酸样物质的荧光峰发生变化，这可能是由光降解引起的。河流水体中DOC浓度与无机阴离子和EC呈显著相关。然而，在地下水中没有观察到这种相关性。湖泊水体阴离子浓度相对于DOC浓度较低。结果表明，地下水、河流和湖泊水体中FDOM的光学和化学性质存在显著差异，说明了同一流域环境对不同FDOM的影响。
Fluorescent dissolved organic matters ( FDOM) in the groundwater-river-lake environments were investigated using three-dimensional excitation-emission matrix ( EEM) and measuring the dissolved organic carbon ( DOC), inorganic anions and electric conductivity ( EC) in shallow groundwater, river and lake waters. DOC concentrations were high and largely varied in groundwater, 16 - 328 mu M C ( mean 109 +/- 88 mu M C), and in river waters, 43 - 271 mu M C mean 158 +/- 62 mu M C) and were very low in the lake Biwa waters, 89 - 97 mu M C ( mean 93 +/- 2 mu M C). The fluorescence properties of EEM showed that the fulvic-like components ( peak C, peak A and peak M) were dominated in groundwater and river waters, but protein-like components ( peak T) was in lake waters. The peak C was observed at Ex/Em 320 +/- 9/424 +/- 5 nm in groundwater, and 340 +/- 5/ 432 +/- 4 nm in river waters, but the lake waters detected the two peaks, 347 +/- 7/441 +/- 11 nm ( peak C) as a minor peak and 304 +/- 2/421 +/- 8 nm ( peak M) as a major peak. Emission wavelength of peak T was observed to shorten in wavelengths from groundwater to river and then lake waters. Peak T in lake waters showed at shorter in wavelengths ( 279 +/- 2/338 +/- 11 nm) at the middle point of Lake Biwa compared to those of lake shore site ( 283 +/- 3/350 +/- 7 nm). Photoirradiation experiment on upstream waters suggested the changes in the fluorescence peaks of fulvic acid-like substances in lake waters, which might be caused by photo-degradation. DOC concentration was significantly correlated with inorganic anions and EC in river waters. However, such correlations were not observed in groundwater. Anion concentrations in lake waters were low with respect to DOC concentration. These results showed that the optical and chemical properties of FDOM are characteristically varied among groundwater, river and lake waters, indicating the impacts of environments to various FDOM at the same watershed level.