| This article choose the northern city Changchun as the study area, using five-step extraction method to discuss the relationship between Cd fractions and bioavailability, calculating the migration coefficient and enrichment factor of Cd, and discussing the migration characteristics of cadmium in soil-vegetable system in sewage irrigation district. The research has shown that：the Cd fractions in soil mainly exists in the state of Cd exchangeable fraction>Cd ferric-manganese oxidation fraction>Carbonate-bound or bound to organic Cd fraction>residual Cd fraction, the Cd coefficient migration of Jijia and Sijianfang are 0.367and 0.651,the sewage irrigation district excessive the national standard value of cadmium, the cadmium content distribution characteristics presented the law of root>leaf>stem>fruit; Jijia and Sijianfang shows the same feature：soil-root enrichment coefficient>stem-leaves migration coefficient, Cd was mainly enriched in the roots; the migration coefficient of Jijia tomato stems-leaves is the highest, while the soil-root enrichment factor of Sijianfang is the highest; the soil-root enrichment factor of Sijianfang cabbage, tomatoes is higher than the Jijia vegetables, because of the active form Cd is higher than Jijia , the higher the content in soil, the larger the absorption by vegetables. |
