Details

Autor(en) / Beteiligte

• Fan, Tuantuan
• Yao, Xin
• Ren, Haoyu
• Ma, Feiyang
• Liu, Li
• Huo, Xiaojia
• Lin, Tong
• Zhu, Haiyan
• Zhang, Yinghao

Titel

Multi-spectroscopic investigation of the molecular weight distribution and copper binding ability of dissolved organic matter in Dongping Lake, China

Ist Teil von

• Environmental pollution (1987), 2022-05, Vol.300, p.118931-118931, Article 118931

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2022

Quelle

MEDLINE

Beschreibungen/Notizen

• The properties and metal-binding abilities of dissolved organic matter (DOM) rely on its molecular weight (MW) structure. In this study, the spatial differences of DOM in compositions, MW structures, and binding mechanisms with copper (Cu2+) in Dongping Lake were investigated by applying excitation-emission matrix combining parallel factor analysis (EEM-PARAFAC), synchronous fluorescence (SF) spectra, two-dimensional correlation spectra (2D-COS), and Fourier transform infrared (FTIR) spectra. The EDOM for the entrance of the Dawen River and PDOM for the macrophyte-dominated region were divided from DOM of Dongping Lake based on hierarchical clustering analysis (HCA) and principal component analysis (PCA) and were size-fractioned into MW < 500 kDa and <100 kDa fractions. According to EEM-PARAFAC, Dongping Lake was dominated by tryptophan-like substances with MW < 500 kDa. The concentration of PDOM was higher than that of EDOM (p < 0.05). 2D-COS showed that protein-like components preceded humic-like components binding to Cu2+ regardless of sample type (215 nm > 285 nm > 310–360 nm). The Cu2+ binding capacity of DOM exhibited specific differences in space, components, and molecular weights. The humic-like component 1 (C1) and tryptophan-like component 4 (C4) of PDOM showed stronger binding abilities than those of EDOM. Endogenous tryptophan-like component 4 (C4) had a higher binding affinity for Cu2+ than humic-like components (logKa: C4 > C1 > C2) in PDOM irrespective of MW. Humic-like components with MW < 500 kDa displayed higher binding potentials for Cu2+. FTIR spectra showed that the main participants of DOM-Cu complexation included aromatic hydrocarbons, aliphatic groups, amide Ⅰ bands, and carboxyl functional groups. This study provides spatial-scale insights into the molecular weight structure of DOM in influencing the behavior, fate, and bioavailability of heavy metals in lakes. [Display omitted] •Study focuses on spatial difference, MW structure, and metal binding capacity of DOM.•DOM is mainly dominated by low molecular weight fractions.•Humic-like components with MW < 500 kDa exhibited high binding potentials.•Aromatic hydrocarbons, amide Ⅰ, aliphatic, and carboxyl participate in complexation.•Ultrafiltration technology, EEM-PARAFAC, 2D-COS, FTIR were applied.