کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5745755 1618781 2018 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Thermodynamic parameters for the protonation and the interaction of arsenate with Mg2+, Ca2+ and Sr2+: Application to natural waters
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست شیمی زیست محیطی
پیش نمایش صفحه اول مقاله
Thermodynamic parameters for the protonation and the interaction of arsenate with Mg2+, Ca2+ and Sr2+: Application to natural waters
چکیده انگلیسی


- Thermodynamic parameters for AsO43--H+, Mg2+, Ca2+, Sr2+ interactions are reported.
- For the first time, both ionic strength and temperature are taken into account.
- Speciation profiles of arsenate in some natural waters are simulated.

Thermodynamic parameters for the protonation of AsO43− and for the interaction with Mg2+, Ca2+ and Sr2+ were reported, comprehensive also of their dependence on ionic strength, considering the 0.1 ≤ I ≤ 1 M range and using NaCl as background salt. The same speciation models were obtained for Mg2+, Ca2+ and Sr2+ systems, with the formation of three different species: ML, MLH and MLH2 (L = AsO43−). Mono- and di-protonated species were very weak, with formation constant values (log K) ranging from 1.45 to 3.23. In order to have a complete picture of thermodynamic properties of the systems under study and to fill the shortage of thermodynamic data on arsenate complex systems, the ligand protonation and metal complex enthalpies were also determined by calorimetric titrations, at t = 25 °C and in NaCl at I = 0.7 M (for H+-AsO43- species also at I = 0.1 M). On the light of the proposed speciation models, examples of As(V) distribution in some natural waters are reported.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemosphere - Volume 190, January 2018, Pages 72-79
نویسندگان
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