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 wrote:

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

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Kansas State University

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785-532-6094 (FAX)

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My2Cents, strange features in spectra can be also induced by mixtures of different species (especially from different oxidation states, especially at low energies) best regards Stefan Mangold Karlsruhe Institute of Technology (KIT) Am 16.10.2020 um 07:26 schrieb Ganga Hettiarachchi mailto:ganga@ksu.edu>: 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... _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.govmailto:Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit