کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4411359 1307590 2011 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Role of microbial exopolymeric substances (EPS) on chromium sorption and transport in heterogeneous subsurface soils: II. Binding of Cr(III) in EPS/soil system
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست شیمی زیست محیطی
پیش نمایش صفحه اول مقاله
Role of microbial exopolymeric substances (EPS) on chromium sorption and transport in heterogeneous subsurface soils: II. Binding of Cr(III) in EPS/soil system
چکیده انگلیسی

Laboratory batch sorption and column experiments were performed to investigate the effects of microbial EPSs isolated from Pseudomonas putida P18, Pseudomonas aeruginosa P16 and Pseudomonas stutzeri P40 on Cr(III) mobility in heterogeneous subsurface soils. Our batch and column results indicate that microbial EPS may have a pronounced effect on Cr(III) sorption and transport behavior depending on system conditions (e.g., pH, type of EPS). While EPS had no effect on Cr(III) sorption at pH < 5, it led to a significant decrease in Cr(III) sorption under slightly acidic to alkaline pH range. Column experiments performed at pH 7.9 suggest that, in the presence of EPS, chromium(III) was significantly mobilized relative to non-EPS containing system due to the formation less sorbing and highly soluble Cr–EPS complexes and competition of EPS against Cr for surface sites.A two-site non-electrostatic surface chemical model incorporating a discrete ligand approach for the description of Cr–EPS interactions accurately predicted Cr(III) sorption and transport behavior in the presence of EPS under variable chemical conditions. Our simulations show that an accurate description of Cr(III) transport in the presence of EPS requires incorporation of proton and Cr(III) binding by EPS, EPS binding by soil minerals, Cr(III) binding by soil minerals, and ternary Cr(III)–EPS surface complexes into the transport equations. Although this approach may not accurately describe the actual mechanisms at the molecular level, it can improve our ability to accurately describe the effects of EPS on Cr(III) mobility in subsurface environment relative to the use of distribution coefficients (Kd).

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemosphere - Volume 82, Issue 10, March 2011, Pages 1496–1505
نویسندگان
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