کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1695042 1519095 2013 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effective concentration of dichromate anions using layered double hydroxides from acidic solutions
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Effective concentration of dichromate anions using layered double hydroxides from acidic solutions
چکیده انگلیسی

Chromate anion was effectively concentrated on an anion exchanger, layered double hydroxide (LDH), from aqueous solution. The LDHs used in this study were synthesized by hydrothermal reactions using urea hydrolysis as reported previously (Ogawa and Kaiho, 2002). The ion exchange was conducted at pH = 3 to concentrate larger amount of dichromate (Cr2O72 −). The adsorption isotherms indicated the strong interactions of chromate anions with LDHs. Among the tested LDHs (MgAl, NiAl, CoAl, and LiAl-LDHs), LiAl-LDH gave the best result in terms of the adsorbed Cr amount. Since the reaction was started from carbonate forms of layered double hydroxides, only the carbonate anions are released to the environment after the anion exchange. All these facts indicated that the present layered double hydroxides are promising materials for the environmental remediation from Cr contaminated water. If compared with commercially available LDHs and those synthesized by the conventional co-precipitation methods, the LDHs synthesized by hydrothermal reaction using urea hydrolysis were shown to be superior because of the stability and the ease of solid–liquid separation after the ion exchange.

Figure optionsDownload as PowerPoint slideHighlights
► Effective adsorption of chromates from water on layered double hydroxides was achieved.
► The adsorption capacity of chromates on layered double hydroxides is very high.
► The adsorption of dichromate was preferred from acidic aqueous solution at pH of 3.
► The layered double hydroxides used in this study are stable in acidic solutions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Clay Science - Volumes 75–76, May 2013, Pages 109–113
نویسندگان
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