State and solubility of cadmium as related to xenotic inorganic phases generated homogeneously in soils

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 1985

OSTI ID:6711534

Walker, W J

The state and solubility of cadmium in waste-treated soils was investigated. Three sets of experiments were designed to elucidate solid phase control of soil solution cadmium. First, the soil solution composition of two soils amended with either sludge or metal contaminated mulch was examined to determine the presence of anions capable of precipitating or co-precipitating cadmium. Results indicated that no known pure solid phases of cadmium developed but that high concentrations of phosphate, sulfate and carbonate apparently influenced cadmium solubility. Secondly, three soils were amended with 10 ug of cadmium as cadmium acetate/g of soil. Three different levels of glycerophosphate, cysteine and acetate were added to the soils and incubated at constant temperature and water content in order to release phosphate, sulfate and alkalinity under conditions conducive for homogeneous precipitation. Another set of treatments was prepared in the same fashion with an additional amendment of calcium carbonate to raise soil pH's to 7.0. In the presence of sulfate, cadmium solubility increased with no apparent solid phase formation. The addition of calcium carbonate shifted solid phase control to either calcium carbonate or calcium sulfate. The generation of alkalinity by acetate addition produced solid phase calcium carbonate which in turn controlled cadmium solubility through chemisorption of cadmium on calcite surfaces. In the presence of monobasic calcium phosphate, cadmium was interfacially adsorbed. In the presence of dibasic calcium phosphate, however, cadmium was homogeneously precipitated in the host crystal suggesting possible solid solution.

• Research Organization: California Univ., Davis (USA)
• OSTI ID: 6711534
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CADMIUM
LEACHING
SOLUBILITY
ANIONS
CARBONATES
INDUSTRIAL WASTES
MUNICIPAL WASTES
PH VALUE
PHOSPHATES
SULFATES
CARBON COMPOUNDS
CHARGED PARTICLES
DISSOLUTION
ELEMENTS
IONS
METALS
OXYGEN COMPOUNDS
PHOSPHORUS COMPOUNDS
SEPARATION PROCESSES
SULFUR COMPOUNDS
WASTES
510200* - Environment
Terrestrial- Chemicals Monitoring & Transport- (-1989)