Phosphate-induced lead immobilization from different lead minerals in soils under varying pH conditions

• Published in: Environmental pollution (1987) 2008-03, Vol.152 (1), p.184-192
• Main Authors: Cao, Xinde, Ma, Lena Q., Singh, Satya P., Zhou, Qixing
• Format: Article
• Language: English
• Subjects: Applied sciences; Biological and physicochemical properties of pollutants. Interaction in the soil; Carbonates - chemistry; Contaminated soil; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Restoration and Remediation - methods; Exact sciences and technology; Hydrogen-Ion Concentration; Immobilization; immobilization in soil; lead; Lead - chemistry; Lead minerals; Minerals; Oxides - chemistry; Phosphate; Phosphates - chemistry; polluted soils; Pollution; Pollution, environment geology; remediation; sandy loam soils; Soil; Soil and sediments pollution; soil pH; Soil Pollutants - chemistry; soil pollution; soil properties; Solubility
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2007.05.008

This study investigated phosphate-induced lead immobilization from different Pb minerals in soils under varying pHs. Four soils were used, including one Pb-contaminated soil (NC-Soil) and three soils spiked with litharge (PbO), cerrusite (PbCO 3), or anglesite (PbSO 4), referred to as PbO-soil, PbCO 3-soil, and PbSO 4-soil, respectively. The soils were equilibrated with KCl and Ca(H 2PO 4) 2·H 2O under pH of 3–7. At low pH (3 and 5), Pb solubility followed PbO-soil > PbCO 3-soil > PbSO 4-soil; while at pH = 7, it was PbSO 4-soil > PbO-soil > PbCO 3-soil. Phosphate decreased Pb dissolution time from >180 to