Here we report a survey addressed to determine, at different pH values (pH 4.0, 7.0 and 9.0), the ability of two different water treatment residues, a Fe-based (Fe-WTR) and an Al-based (Al-WTR), to accumulate arsenate and phosphate anions from an aqueous solution and to define the mechanism which regulate the sorption of these anions. Fe-WTR showed a greater As(V) and P(V) sorption capacity respect to Al-WTR at all the pH values investigated, in particular at pH 4.0. The greater capacity of the Fe-WTR to accumulate phosphate at pH 4.0 seems to be linked to the higher content of manganese ions compared to Al-WTR, which can give rise, with phosphate ions, to the formation of MnHPO4 precipitates. Sequential extraction of As(V)- or P(V)-WTRs suggested that the main mechanism governing the sorption of both two anions likely involve the formation of inner-sphere surface complexes [Fe/Al-O-As(P)]. Such a coordination mode was supported by the FT-IR spectra that exhibit well resolved band at 865cm-1 and 1040cm-1 attributable to ν(As-O) or ν(P-O) stretching vibration, respectively.

Water treatment residues as accumulators of oxoanions in soil. Sorption of arsenate and phosphate anions from an aqueous solution / Castaldi, Paola; Mele, Elena; Silvetti, Margherita; Garau, Giovanni; Deiana, Salvatore Andrea. - In: JOURNAL OF HAZARDOUS MATERIALS. - ISSN 0304-3894. - 264:(2014), pp. 144-152. [10.1016/j.jhazmat.2013.10.037]

Water treatment residues as accumulators of oxoanions in soil. Sorption of arsenate and phosphate anions from an aqueous solution

CASTALDI, Paola
Writing – Original Draft Preparation
;
SILVETTI, Margherita
Data Curation
;
GARAU, Giovanni
Writing – Review & Editing
;
DEIANA, Salvatore Andrea
Supervision
2014-01-01

Abstract

Here we report a survey addressed to determine, at different pH values (pH 4.0, 7.0 and 9.0), the ability of two different water treatment residues, a Fe-based (Fe-WTR) and an Al-based (Al-WTR), to accumulate arsenate and phosphate anions from an aqueous solution and to define the mechanism which regulate the sorption of these anions. Fe-WTR showed a greater As(V) and P(V) sorption capacity respect to Al-WTR at all the pH values investigated, in particular at pH 4.0. The greater capacity of the Fe-WTR to accumulate phosphate at pH 4.0 seems to be linked to the higher content of manganese ions compared to Al-WTR, which can give rise, with phosphate ions, to the formation of MnHPO4 precipitates. Sequential extraction of As(V)- or P(V)-WTRs suggested that the main mechanism governing the sorption of both two anions likely involve the formation of inner-sphere surface complexes [Fe/Al-O-As(P)]. Such a coordination mode was supported by the FT-IR spectra that exhibit well resolved band at 865cm-1 and 1040cm-1 attributable to ν(As-O) or ν(P-O) stretching vibration, respectively.
2014
Water treatment residues as accumulators of oxoanions in soil. Sorption of arsenate and phosphate anions from an aqueous solution / Castaldi, Paola; Mele, Elena; Silvetti, Margherita; Garau, Giovanni; Deiana, Salvatore Andrea. - In: JOURNAL OF HAZARDOUS MATERIALS. - ISSN 0304-3894. - 264:(2014), pp. 144-152. [10.1016/j.jhazmat.2013.10.037]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11388/46304
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