孟加拉国恒河中溶解性有机物（DOM）的特征，来源和季节性变化,Environmental Processes

当前位置： X-MOL 学术 › Environmental Processes › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

孟加拉国恒河中溶解性有机物（DOM）的特征，来源和季节性变化
Environmental Processes Pub Date : 2021-02-15 , DOI: 10.1007/s40710-021-00499-y
Nahin Mostofa Niloy , Md. Morshedul Haque , Shafi M Tareq

摘要

这项研究使用三维激发-发射矩阵（3DEEM）光谱和平行因素分析（PARAFAC）研究了恒河中源的季节性变化和溶解性有机物（DOM）的荧光特征。3DEEM和PARAFAC分别鉴定了五个荧光团（峰：A，C，M，T，W）和四个荧光成分，即去污剂，富里酸（M型），富里酸（C型）和类蛋白。与季风后（11月至2月）相比，在季风前（3月至6月）和季风（7月至10月）显示出较高的荧光特性。溶解的有机碳（DOC）和比紫外线吸收率（SUVA ₂₅₄）分别在1.85-4.7 mg / L和1.23-5.51 L / mg-m的范围内。全年中，DOM成分都是新鲜的和微生物来源的。当地的水文和理化条件支持季风后的自生和芳香性DOM的产生，以及季风前和季风期间陆生的自然和人为DOM的丰富性。DOM的分子量从季风前期开始下降，并一直持续到季风，这是由于陆地来源的DOM和光辐照以及微生物活性的增加。色氨酸样荧光（TLF）在季风前和季风的整个峰值流量期间显示出高强度，表明恒河被微生物污染的风险为中度。

强调

•在季风开始时，DOC浓度和DOM荧光强度达到最高值，并表现出很高的季节性变化。

•恒河携带的DOM的组成在一年中的不同时间有所不同，在季风前和季风后期，新鲜的，土生的，芳香性较低的DOM占主导地位。

•PARAFAC模型确定了四个荧光DOM成分（洗涤剂，富维克（M样），富维克（C样）和蛋白样），它们随降雨和河流流量显示出高的季节变化性。

图形概要

"点击查看英文标题和摘要"

Characteristics, Sources, and Seasonal Variability of Dissolved Organic Matter (DOM) in the Ganges River, Bangladesh

Abstract

This study investigated seasonal variability of sources and fluorescence characteristics of dissolved organic matter (DOM) in the Ganges River using three-dimensional excitation-emission matrix (3DEEM) spectroscopy and parallel factor analysis (PARAFAC). 3DEEM and PARAFAC identified five fluorophores (Peak: A, C, M, T, W) and four fluorescent components, i.e., detergent, fulvic acid (M-type), fulvic acid (C-type), and protein-like, respectively, showing high fluorescence characteristics in the pre-monsoon (March-June) and monsoon (July-October) compared to the post-monsoon (November-February) period. Dissolved organic carbon (DOC) and Specific ultraviolet absorbance (SUVA₂₅₄) were in the range 1.85-4.7 mg/L and 1.23-5.51 L/mg-m, respectively. DOM components were both fresh and microbial-derived throughout the year. Local hydrological and physicochemical conditions supported the autochthonous and aromatic DOM production in post-monsoon, and richness of terrestrial-derived natural and anthropogenic DOM in the pre-monsoon and monsoon periods. The molecular weight of DOM decreased from the mid of pre-monsoon and continued till monsoon with the increase of terrestrial-derived DOM and photo-irradiation as well as microbial activity. Tryptophan-like fluorescence (TLF) showed high intensity throughout the peak-flow pre-monsoon and monsoon periods, demonstrating a high to intermediate risk of microbial contamination of the Ganges River. The seasonal variability of DOM characteristics suggests that the source and biogeochemistry of DOM in the Ganges Rivers might be sensitive to local hydrology and climate.

Highlights

• DOC concentrations and DOM fluorescence intensity attained their highest values at the beginning of monsoon and showed high seasonal variability.

• The compositions of DOM carried by the Ganges River varied at different times of the year, and fresh, autochthonous and less aromatic DOM dominated in the late pre-monsoon and monsoon.

• PARAFAC model identified four fluorescent DOM components (detergent-, fulvic- (M like), fulvic- (C like) and protein-like) which showed high seasonal variability with rainfall and river discharge.

Graphical abstract

更新日期：2021-02-15

点击分享查看原文

点击收藏