Study Of Influence Factors On Alfalfa Enrichment Of Cd、Co

Plants be poisoned by the low content of heavy metal Cd in soil, but also affect human health through the food chain. Chinese first national survey of soil pollution showed the worrying issue on quality of cultivated soil system by heavy metals.Therefore, it is crucial to develop a wide applicability technique for the remediation of contaminated soils.In this study,Cd、Co form in soil influenced by EDTA、CA、GA was investigated by static absorbing test;uptake and accumulation of Cd、Co by alfalfa from soil in Cd、Co single and combined pollution system was discussed though pot experiment.In addition, bio-enrichment coefficient of Cd、Co influence by EDTA、CA、GA were analyzed by alfalfa from soil in Cd、Co single pollution system with pot experiment.The main results are shown as follows:(1) In the single pollution of Cd in soil when exogenous Cd range concentration is0~30 mg/kg, bio-enrichment coefficient(BCF) of Cd change regularly and reached maximum in alfalfa from soil when the exogenous concentration of Cd is 10 mg/kg.In the single pollution of Co in soil when exogenous Co range concentration is 0~90mg/kg,bio-enrichment coefficient of Co change regularly and reached maximum in alfalfa from soil when the exogenous concentration of Co is 60 mg/kg.(2) In the combined pollution system of Cd、Co in soil(Cd:0~30 mg/kg、Co:0 ~ 90 mg/kg),with the addition of Cd increased in soil, accumulation of Cd was slightly decreased in alfalfa leaf and greatly in root; BCF was maximized when Cd was 30 mg/kg and Co was 90 mg/kg in soil.With the addition of Co increased,the accumulation of Cd was greatly reduced in alfalfa,and BCF was maximized in alfalfa when Cd was 10 mg/kg and Co was 60 mg/kg in soil.(3) When the concentration of agents added in soil ranged 0 ~ 1 mmol/kg,enrichment of Co was increased significantly in alfalfa compared with control,and the significance of the effect from agents were contrasted with GA>EDTA> CA in alfalfa root 、GA>EDTA> CA in alfalfa stem and leaf.When the concentration of agents added in soil ranged 0~5 mmol/kg, enrichment of Cd was increased significantly in alfalfa compared with control,and the significance of the effect from agents were contrasted in alfalfa root with EDTA>GA>CA,also in stem and leaf withEDTA>GA>CA in.(4) BCF of Cd、Co were increased significantly in alfalfa compared with control when concentration of agents in soil ranged 0 ~ 15 mmol/kg, and the significance effects were contrast from agents of Cd with EDTA>GA>CA in alfalfa 、EDTA>GA>CA of Co in alfalfa.