Environmental Engineering Reference
In-Depth Information
TABLE 6.1.2
Selected Treatment Studies for Heavy Metals and Radionuclides Using
Phosphates; Includes Laboratory Studies, Field Trials, and Applications
Metal/
Metalloid
Studied
Media/
Conditions
Phosphate
Treatment
Mechanism/Solid
Phases Formed
References
Actinides
Soil
Organo-
phosphorous
Not determined
27
As, Cd,
Pb, Zn
Soil
Phosphate rock
Replacement of As by P
from soil binding sites
increased mobility of As
uptake by the plant
28a
As, Cd,
Pb, Zn
Contaminated
smelter soil
Phosphate rock,
diammonium
phosphate
Not determined
29
Cd
Soil
Monobasic
calcium
phosphate
Not determined
30
Cd
Aqueous solution
Bone char
Substitution of Cd for Ca
and physical adsorption of
Cd
31
Cd
Aqueous solution
Synthetic
hydroxyapatite
Substitution of Cd for Ca
through diffusion and ion
exchange
32
Cd
Aqueous solution
Synthetic
hydroxyapatite
Not determined
33
Cd
Aqueous solution
Synthetic
hydroxyapatite
prepared in the
presence of Cd
Substitution of Cd for Ca
34
Cd
Aqueous solution;
pH 3 and 9
Hydroxyapatite
Cd sorbed to apatite surface
35
Cd
Aqueous solution;
pH 4.5 to 5
Synthetic
hydroxyapatite
Substitution of Cd for Ca
36
Cd, Cu,
Pb, Zn
Aqueous solution;
pH 5 to 6
Synthetic
hydroxyapatite
Substitution of Cd for Ca
32
Cd, Cu,
Pb, Zn
Combustion ash
from municipal
solid waste
incineration
Phosphoric acid
Formed calcium
phosphates, tertiary metal
phosphates, and apatite
family minerals
depending on the pH of
the experiment
37
Cd, Cu,
Pb, Zn
Municipal solid
incineration waste
Not reported
Not determined
38
(continued)
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