DOI: 10.1016/j.watres.2018.07.075
Scopus记录号: 2-s2.0-85053070296
论文题名: Dynamic molecular size transformation of aquatic colloidal organic matter as a function of pH and cations
作者: Xu H. ; Lin H. ; Jiang H. ; Guo L.
刊名: Water Research
ISSN: 431354
出版年: 2018
卷: 144 起始页码: 543
结束页码: 552
语种: 英语
英文关键词: Cations
; Colloidal dispersion/aggregation
; Colloidal organic matter
; Flow field-flow fractionation
; Molecular size continuum
Scopus关键词: Biogeochemistry
; Biological materials
; Colloids
; Complexation
; Flow fields
; Fluorescence
; Fluorescence spectroscopy
; Fourier transform infrared spectroscopy
; Fractionation
; Lakes
; Liquid chromatography
; Organic compounds
; pH
; Positive ions
; Rivers
; Zeta potential
; Attenuated total reflectance Fourier transform infrared
; Colloidal dispersion
; Dissolved organic matters
; Fate and transport of contaminant
; Flow field flow fractionations
; Flow-field flow fractionation
; Molecular size
; Parallel factor analysis
; Agglomeration
; cation
; colloid
; complexation
; dispersion
; flow field
; fractionation
; lake water
; molecular analysis
; organic matter
; pH
; pollutant transport
; river water
; transformation
英文摘要: Knowledge of the dynamic changes in molecular size of natural colloidal organic matter (COM) along the aquatic continuum is of vital importance for a better understanding of the environmental fate and ecological role of dissolved organic matter and associated contaminants in aquatic systems. We report here the pH- and cation-dependent size variations of COMs with different sources (river and lake) quantified using flow field-flow fractionation (FIFFF), fluorescence spectroscopy and parallel factor analysis (PARAFAC), attenuated total reflectance Fourier transform infrared (ATR–FTIR) spectroscopy, and zeta potential analysis. Increasing pH caused a decline in molecular sizes and an obvious size transformation from the >10 kDa to 5–10 kDa and further to 1–5 kDa size fraction, whereas the opposite trend was observed for increasing cation (e.g., Ca2+ and Cu2+) abundance. Compared with lakewater COM, the riverwater COM exhibited a greater pH-dependent dispersion but less extent in cation-induced aggregation, demonstrating that the dispersion and aggregation dynamics were highly dependent on COM source and solution chemistry (e.g., pH and cations). Based on ATR–FTIR analysis, the extensive dissolution of C=O and C–O functional groups resulted in a greater pH-dependent dispersion for river COM. Fluorescence titration revealed that, despite their similar cation-induced aggregation behavior, the binding constants of all the PARAFAC-derived components for Cu2+ were 1–2 orders of magnitude higher than those for Ca2+ (logKM: 4.54–5.45 vs. 3.35–3.70), indicating a heterogeneous nature in cation-DOM interactions. The greater extent of decline in zeta potential for lake COM suggested a Ca-induced charge neutralization and aggregation mechanism. However, for Cu-induced aggregation, chemical complexation was the predominant pathway for the river COM, with higher binding constants, while charge neutralization and chemical complexation co-induced the aggregation of lake COM. Thus, natural COMs may have different environmental behavior along the aquatic continuum and further affect the fate and transport of contaminants in aquatic environments. © 2018 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112523
Appears in Collections: 气候减缓与适应
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作者单位: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; School of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 E Greenfield Ave., Milwaukee, WI 53204, United States
Recommended Citation:
Xu H.,Lin H.,Jiang H.,et al. Dynamic molecular size transformation of aquatic colloidal organic matter as a function of pH and cations[J]. Water Research,2018-01-01,144