Chemical composition and Pb(II)binding of dissolved organic matter in a hypersaline lake in China  

作　　者：Keli YANG Yaoling ZHANG Yaping DONG Wu LI 

机构地区：[1]Key Laboratory of Comprehensive and Highly Effi cient Utilization of Salt Lake Resources,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining 810008,China [2]Qinghai Technology Research and Development Center of Comprehensive Utilization of Salt Lakes Resources,Xining 810008,China [3]Qinghai Provincial Key Laboratory of Resources and Chemistry of Salt Lakes,Xining 810008,China

出　　处：《Journal of Oceanology and Limnology》2022年第1期113-127,共15页海洋湖沼学报（英文）

基　　金：Supported by the Natural Science Foundation of Qinghai Province(Nos.2020-ZJ-940Q,2014-ZJ-937Q);the West Light Foundation of the Chinese Academy of Sciences(No.E010GC09);the Youth Innovation Promotion Association CAS(No.E010GC15)。

摘　　要：Dissolved organic matter(DOM)plays a vital role in promoting carbon and nutrient cycling.It is a food source for organisms and controls the migration and transformation of trace metals and other contaminants in aquatic systems.The contributions of aquatic DOM to the environment and ecology of a system are closely related to its abundance and chemical structure.In this study,the chemical composition and binding properties of DOM in a hypersaline lake watershed were investigated for the fi rst time using dissolved organic carbon(DOC)analysis,absorption spectroscopy,Fourier transform infrared spectroscopy,pyrolysis-GC-MS(Py-GC-MS),and fl uorescence parallel factor(PARAFAC)analysis combined with Pb(II)titration techniques.The results showed that DOM from the tributaries that fl owed into the lake had a lower DOC content,higher molecular weight,and higher specifi c UV absorbance than the DOM in lake water.Protein-like fl uorophores were mainly found in tributary and lake surface water DOM(LSDOM)and humic-like substances were abundant in lake groundwater DOM(LGDOM).Using this multi-methodological approach,we found that the DOM from the hypersaline lake watershed was mainly from microbial origins,and consisted of aromatics,carbohydrates,and aliphatics.The results from quantitative analysis showed that DOM from the infl owing tributaries contained more aromatics,lower carbohydrates,and lower aliphatics than DOM in the lake.Monocyclic aromatic hydrocarbons and carbohydrates were more abundant in LSDOM than LGDOM.The results from the Pb(II)titration technique coupled with PARAFAC analysis suggested that PARAFAC-derived components had relatively low condition stability constants(log K_(M)<2).Of the two types of lake DOM,the LGDOM had a higher Pb(II)binding potential than the LSDOM.From this study we have improved our understanding of how DOM within a hypersaline lake watershed varies in its composition and potential to bind with metals.

关 键 词：dissolved organic matter hypersaline lake watershed composition parallel factor analysis Pb(II)titration 

分 类 号：X524[环境科学与工程—环境工程]