不同土壤环境中镉的形态分配及活性研究

FRACTIONATION AND AVAILABILITY OF ADDED SOLUBLE CADMIUM IN SOIL ENVIRONMENT

本文研究了两种负荷水平(2,8ppm)的可溶性镉进入到三种不同土壤环境(酸性、中性及石灰性土壤环境)后的形态分配规律、影响因子以及各形态的活性。结果表明:酸性士壤、中性土壤及石灰性土壤交换态镉分别为40—50％,60—80％,10—20％。各类土壤松结有机态镉为5—20％,残留态10—70％,石灰性土壤中碳酸盐结合态为10—20％。土壤各组份对镉的富集作用因土壤类型与负荷水平而异。不同供试土壤中活性镉的形态是:中、酸性土壤主要为交换态与松结有机态,而石灰性土壤上则以交换态为活性镉的主要给源。

Fractionation and availability of added cadmium with two load levels in three soil environment(acidic,neutral and calcareous soils)were studied.Results show that exchangeable cadmium(EXC-Cd)is about 40-50%,60-80% and 10-20% in acidic,neutral and calcareous soil,respectively,and cadmium wea-ky bound to organic mattcr(WBO),cadmium residue in primary and secondary minerals(RES-Cd)and cadmium bound to carbonate(CARB-Cd)accounted to be 5-20%,10-70% and 10-20%,respectively,Distribution coeffient(DC)of EXC-Cd increased with the level,but that of RES-Cd decreased.Results also show that EXC-Cd were the most active or available form,and then WBO-Cd in Acidic-neutral soil.Fractionation and availability of added cadmium with two load levels in three soil environment(acidic,neutral and calcareous soils)were studied.Results show that exchangeable cadmium(EXC-Cd)is about 40-50%,60-80% and 10-20% in acidic,neutral and calcareous soil,respectively,and cadmium wea-ky bound to organic mattcr(WBO),cadmium residue in primary and secondary minerals(RES-Cd)and cadmium bound to carbonate(CARB-Cd)accounted to be 5-20%,10-70% and 10-20%,respectively,Distribution coeffient(DC)of EXC-Cd increased with the level,but that of RES-Cd decreased.Results also show that EXC-Cd were the most active or available form,and then WBO-Cd in Acidic-neutral soil.