| 摘要 |
PURPOSE:To condition contaminated soil, by a method wherein a metal-capturing agent consisting of a specified resin is mixed with contaminated soil to retain heavy metals contained in the soil as ions which are not supplied to plants. CONSTITUTION:A heavy metal-capturing agent consisting a urea-thiourea-formualdehyde, co-condensation resin as a soil conditioner is mixed with contaminated soil to capture heavy metals. Said heavy metal-capturing agent is produced by reacting a mixt. of urea and thiourea (in a mole ratio of 1-9:1) with formaldehyde under alkaline conditions, acidifying the reaction mixt. with HCl, heating it to insolubilize the reaction product in water, washing the resulting solid with water, drying and powdering the solid. |
