Hello Ganga,
That is a very interesting spectrum. Given what you said about the system,
the lower energy feature at ~ 2146 eV should be Fe(III)-bonded phosphate
and the feature at ~2149 eV should be Al(III)-bonded phosphate. Both
produce pre-white line absorption peaks, but the Al-bonded phosphate peak
is closer to the white line and less distinct in spectra of Al-phosphates
like variscite and non-crystalline Al-phosphate, for example (see Khare et
al. 2007. *Geochimica et Cosmochimica Acta* 71:4405, Fig. 5C). A
significant proportion of the phosphate in your system apparently
precipitated with Al-13 polymer structures in the aluminum chlorohydrate.
Dean
On Fri, Oct 16, 2020 at 1:26 AM Ganga Hettiarachchi
All,
Can anyone provide some insight into the pre-edge “features” in this P XANES spectrum?
This is the P XANES spectrum we got for a recovered P-product (rich in Fe and Al) from wastewater using the AnMBR technology. During the coagulation process, our collaborators (environmental engineers) used stock solutions of aluminum chlorohydrate (ACH) and FeCl3.
Thanks very much.
Best regards,
Ganga
--------------------
Ganga M. Hettiarachchi, Ph.D.
Professor of Soil and Environmental Chemistry
Department of Agronomy
2107 Throckmorton Plant Sciences Center
1712 Claflin Road
Kansas State University
Manhattan, KS 66506 USA
785-532-7209 (office)
785-532-6094 (FAX)
http://www.agronomy.k-state.edu/research/soil-and-environment/soil-environme...
http://www.agronomy.k-state.edu/people/faculty/hettiarachchi-ganga/index.htm...
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