caa a22 4500 378927264 CHVBK 20180305123620.0 cr unu---uuuuu 161128e20041101xx s 000 0 eng 10.1524/ract.92.9.719.55000 doi (NATIONALLICENCE)gruyter-10.1524/ract.92.9.719.55000 Formation of hydroxyapatite in soils using calcium citrate and sodium phosphate for control of strontium migration [Elektronische Daten] [Robert C. Moore, Charles Sanchez, Kathleen Holt, Pengchu Zhang, Huifang Xu, Gregory R. Choppin] 90Sr contamination is a major problem at several U.S. sites. At some sites, 90Sr has migrated deep underground making site remediation difficult. In this paper, we describe a novel method for precipitation of hydroxyapatite, a strong sorbent for 90Sr, in soil. The method is based on mixing a solution of calcium citrate and sodium phosphate in soil. As the indigenous soil microorganisms mineralize the citrate, the calcium is released and forms hydroxyapatite. Soil, taken from the Albuquerque desert, was treated with a sodium phosphate solution or a sodium phosphate/calcium citrate solution. TEM and EDS were used to identify hydroxyapatite with CO32- substitutions, with a formula of (Ca4.8Na0.2)[(PO4)2.8(CO3)0.2](OH), in the soil treated with the sodium phosphate/calcium citrate solution. Untreated and treated soils were used in batch sorption experiments for Sr uptake. Average Sr uptake was 19.5, 77.0 and 94.7% for the untreated soil, soil treated with sodium phosphate, and soil with apatite, respectively. In desorption experiments, the untreated soil, phosphate treated soil and apatite treated soil released an average of 34.2, 28.8 and 4.8% respectively. The results indicate the potential of forming apatite in soil using soluble reagents for retardation of radionuclide migration. © 2004 Oldenbourg Wissenschaftsverlag GmbH Laboratory techniques, experiments nationallicence Analytical chemistry nationallicence Inorganic chemistry nationallicence Moore Robert C. aut Sanchez Charles aut Holt Kathleen aut Zhang Pengchu aut Xu Huifang aut Choppin Gregory R. aut Radiochimica Acta/International journal for chemical aspects of nuclear science and technology Oldenbourg Wissenschaftsverlag GmbH 92/9-11/2004(2004-11-01), 719-723 0033-8230 92:9-11/2004<719 2004 92 ract https://doi.org/10.1524/ract.92.9.719.55000 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1524/ract.92.9.719.55000 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Moore Robert C. aut NATIONALLICENCE 700 1- Sanchez Charles aut NATIONALLICENCE 700 1- Holt Kathleen aut NATIONALLICENCE 700 1- Zhang Pengchu aut NATIONALLICENCE 700 1- Xu Huifang aut NATIONALLICENCE 700 1- Choppin Gregory R. aut NATIONALLICENCE 773 0- Radiochimica Acta/International journal for chemical aspects of nuclear science and technology Oldenbourg Wissenschaftsverlag GmbH 92/9-11/2004(2004-11-01), 719-723 0033-8230 92:9-11/2004<719 2004 92 ract CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter