کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1263201 1496720 2008 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Aggregation of riverine colloidal iron in estuaries: A new kinetic study using stopped-flow mixing
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Aggregation of riverine colloidal iron in estuaries: A new kinetic study using stopped-flow mixing
چکیده انگلیسی

The kinetics of aggregation of riverine colloidal iron have been examined using a stopped-flow technique which probes the first few seconds of mixing between river and sea water end members. A significant fraction, up to 80%, of the colloidal iron is aggregated during the first 1–2 s of mixing, indicating that the aggregation process is much faster than previously thought. Most of the aggregation induced by seawater results from the divalent cations Mg2+ and Ca2+, with the overall ionic strength having little influence. At equal concentrations of 27 mM, the rate of aggregation by alkaline earth cations increased with ionic size Mg2+ < Ca2+ < Sr2+ < Ba2+. The aggregation rates were indifferent to the anion (Cl− or SO42−) present. Very high aggregation rates were also induced by the common water treatment coagulant Al2(SO4)3 at concentrations in the range 20–30 µM Al(III), several orders of magnitude lower that those used for the seawater cations. Our results support the view that specific chemical interactions between the cations and the colloid particle surface, rather than simple electrical effects, control the colloid stability.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Marine Chemistry - Volume 110, Issues 3–4, 16 June 2008, Pages 205–210
نویسندگان
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