Effect of incubation temperature and wet-dry cycle on the availabilities of Cd, Pb and Zn in soil.
The effect of incubation temperature and wet-dry cycle on the availabilities of Cd, Pb and Zn was studied. Three soils with pH ranging from 3.8 to 7.3, organic carbon (OC) from 0.7% to 2.4%, and clay from 12.3% to 35.6% were selected. Soils were spiked with reagent grade Cd(NO3)2, Pb(NO3)2, and Zn(NO3)2 at concentrations of 30 mg Cd/kg soil, 300 mg Zn/kg soil and 2000 mg Pb/kg soil. The soils were incubated at 35, 60, 105 degrees C, respectively and went through four wet-dry cycles. Metal availability in soils was estimated by soil extraction with 0.1 mol/L Ca(NO3)2. According to this study, the effect of the spiking temperature on the metal availabilities was different among the metals, soils and wet-dry cycles. Mostly, 35 degrees C was the first recommended spiking temperature for Cd and Pb while no spiking temperature was obviously better than others for Zn. Three wet-dry cycles was recommended regardless of the type of metals and incubation temperature.
Si
Ji-tao
JT
Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China. sijt@tsinghua.edu.cn
Tian
Bao-guo
BG
Wang
Hong-tao
HT
D001682:Biological Availability; D019216:Metals, Heavy / Q000032:analysis* / Q000302:isolation & purification; D008962:Models, Theoretical; D012987:Soil / Q000032:analysis*; D013696:Temperature; D014116:Toxicology / Q000379:methods*
D019216:Metals, Heavy; D012987:Soil