title: Immobilization of lead by phosphate amended Polonite.
abstract: Polonite is an alkaline material that is used to remove nutrients from domestic wastewater and it has been evaluated as a fertilizer. Stabilization of Pb by Polonite and Polonite amended with orthophosphate, PO4, (Polonite-P) was studied. Octacalcium phosphate (Ca8H2(PO4)6·5H2O) was a primary species of PO4 formed on the surface of Polonite-P. Lead was found to be associated with pozzolanic reaction products in Pb treated Polonite and Pb treated Polonite-P samples. Formation of Pb oxides, as precipitates or surface complexes, were substantial constituents of Pb treated Polonite. Dissolution of Ca8H2(PO4)6·5H2O followed by formation of Pb4O(PO4)2 was a probable mechanism of Pb removal by Polonite-P. Polonite-P could be a suitable replacement for current PO4 sources as a Pb stabilization agent. Finally, LDI-TOF was an effective technique for evaluating forms of Pb on Polonite and Polonite-P.
authors.affiliation: Environmental Engineering Program, Department of Geography and Environmental Engineering, U.S. Military Academy, West Point, NY 10996, USA. Electronic address: Michael.Butkus@usma.edu.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Butkus
authors.affiliation: Chemistry Program, Department of Chemistry and Life Science, U.S. Military Academy, West Point, NY 10996, USA.
authors.forename: Dawn E
authors.initials: DE
authors.lastname: Riegner
authors.affiliation: Environmental Engineering Program, Department of Geography and Environmental Engineering, U.S. Military Academy, West Point, NY 10996, USA.
authors.forename: Johannes
authors.initials: J
authors.lastname: Olind
mesh_terms: D000327:Adsorption; D002118:Calcium / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry*; D052918:Environmental Restoration and Remediation; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000032:analysis*; D008962:Models, Theoretical; D010087:Oxides / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D011208:Powders; D012989:Soil Pollutants / Q000032:analysis*; D013499:Surface Properties
chemical_list: D002130:Calcium Phosphates; D010087:Oxides; D010710:Phosphates; C507562:Polonite; D011208:Powders; D012989:Soil Pollutants; C022045:octacalcium phosphate; D007854:Lead; D002118:Calcium
keywords: LDI-TOF; Lead oxide; Pb(4)O(PO(4))(2); Pozzolanic reaction products; Stabilization