Add time:09/25/2019 Source:sciencedirect.com
Understanding the redistribution and retention of chromium(VI) (Cr(VI)) co-precipitated with silicate-containing ferrihydrite during aging is essential to the stabilization and immobilization of Cr(VI) in nature. In this work, Cr(VI) was removed by co-precipitated with silicate-containing ferrihydrite with various Si/Fe ratios at different precipitating pH. The co-precipitates were characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy before and after aging for 9 days at 80 °C. Results showed that silicate not only competed with Cr(VI) adsorbed on ferrihydrite surface by forming inner-sphere complexes, but also inhibited ferrihydrite transforming into more stable and compact iron phases. Ferrihydrite only transformed to hematite at pH0 5.0, and converted to hematite and goethite at pH0 7.5 and 10.0. Cr(VI) was initially removed by silicate-containing ferrihydrite with the removal efficiencies >99.64% at initial pH of 5.0, and it was obviously incorporated into hematite and goethite during the transformation of ferrihydrite. The transformation products influenced the redistribution of Cr(VI), which was beneficial to the retention of Cr(VI) inside the co-precipitates, but not conducive to the adsorption for Cr(VI). The findings that Cr(VI) was removed by a common and metastable precursor of silicate-containing ferrihydrite can promote understanding of three-dimensional transfer and behavior of Cr(VI) during the transformation of silicate-containing ferrihydrite.
We also recommend Trading Suppliers and Manufacturers of Iron(II) molybdate(VI) (cas 13718-70-2). Pls Click Website Link as below: cas 13718-70-2 suppliers
About|Contact|Cas|Product Name|Molecular|Country|Encyclopedia
Message|New Cas|MSDS|Service|Advertisement|CAS DataBase|Article Data|Manufacturers | Chemical Catalog
©2008 LookChem.com,License: ICP
NO.:Zhejiang16009103
complaints:service@lookchem.com Desktop View