重金属Cd污染土壤毒性的发光菌法评价

TOXICITY ASSESSMENT OF Cd CONTAMINATED SOIL USING BIOLUMINESCENCE ASSAY

应用明亮发光杆菌 Ｔ３ 对重金属污染土壤的毒性评价方法进行探索；进行了土壤平衡、土壤浸提实验及土壤中人为添加 Ｃｄ 对明亮发光杆菌 Ｔ３ 的效应实验；确定了土壤最佳平衡时间、土壤浸提剂、土壤最佳浸提时间及草甸棕壤中 Ｃｄ 对明亮发光杆菌 Ｔ３ 的毒性响应水平．实验结果表明：在土壤浸出液的提取过程中，土壤最佳平衡时间为１ ｄ ，最佳浸提液为０ ．１ ｍｏｌ／ Ｌ 盐酸，最佳浸提时间为２ ｈ ；草甸棕壤中 Ｔ３ 菌的发光强度与投加的 Ｃｄ浓度呈显著负相关（ Ｐ＜ ０ ．０１） ，ρ（ Ｃｄ） 对 Ｔ３ 菌的 Ｅ Ｃ５０ 值为２６ ．２ ｍｇ／ｋｇ ．

The bacterial bioluminescence assay with Photobacterium phosphoreum was tested for its application in toxicity assessment of the soil contaminated by heavy metal. Variation of the extraction method for Cd contaminated soil showed 0.1 mol/L HCl was the best extraction method to test the toxicity of artificially contaminated soil. The experiment results also showed that one day was the best time for testing the toxicity of soil and two hours was the best extraction time.Sensitivity and dose/response relationship were estimated using Cd of defined composition. The general detection limit given by EC 50 was determined at about 26.2 mg/kg.