کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4529870 1625987 2011 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Physicochemical and spectroscopic properties of natural organic matter (NOM) from various sources and implications for ameliorative effects on metal toxicity to aquatic biota
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم آبزیان
پیش نمایش صفحه اول مقاله
Physicochemical and spectroscopic properties of natural organic matter (NOM) from various sources and implications for ameliorative effects on metal toxicity to aquatic biota
چکیده انگلیسی

Natural organic matter (NOM), expressed as dissolved organic carbon (DOC in mg C L−1), is an ubiquitous complexing agent in natural waters, and is now recognized as an important factor mitigating waterborne metal toxicity. However, the magnitude of the protective effect, judged by toxicity measures (e.g. LC50), varies substantially among different NOM sources even for similar DOC concentrations, implying a potential role of NOM physicochemical properties or quality of NOM. This review summarizes some key quality parameters for NOM samples, obtained by reverse osmosis, and by using correlation analyses, investigates their contribution to ameliorating metal toxicity towards aquatic biota. At comparable and environmentally realistic DOC levels, molecular spectroscopic characteristics (specific absorbance coefficient, SAC, and fluorescence index, FI) as well as concentrations of fluorescent fractions obtained from mathematical mixture resolution techniques (PARAFAC), explain considerable variability in the protective effects. NOM quality clearly influences the toxicity of copper (Cu) and lead (Pb). NOM quality may also influence the toxicity of silver (Ag), cadmium (Cd) and inorganic mercury (Hg), but as yet insufficient data are available to unequivocally support the latter correlations between toxicity reduction and NOM quality predictors. Cu binding capacities, protein-to-carbohydrate ratio, and lipophilicity, show insignificant correlation to the amelioration offered by NOMs, but these conclusions are based on data for Norwegian NOMs with very narrow ranges for the latter two parameters. Certainly, various NOMs alleviate metal toxicity differentially and therefore their quality measures should be considered in addition to their quantity.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Aquatic Toxicology - Volume 103, Issues 3–4, June 2011, Pages 179–190
نویسندگان
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