土壤浸提液中重金属对发光杆菌T_3的毒性效应

通过测定掺杂Pb2＋、Zn2＋、Cd2＋、Cu2＋和Cr3＋的土壤浸提液中明亮发光杆菌T3的抑制率,研究重金属复合污染对明亮发光杆菌T3的生物毒性效应。按照重金属离子等效应浓度配比的原理,设计均匀试验,用逐步多元回归法构建土壤水浸提液中重金属（Pb2＋、Zn2＋、Cd2＋、Cu2＋和Cr3＋）浓度（Xi）与发光菌抑制率（Y）的响应关系：Y=（-39.596±15.811）-（6.633±0.802）×（-lgXCu）（-lgXZn）＋（59.466±8.731）×（-lgXCd）（-lgXCr）。该模型具有较好的拟合优度（F检验和t检验的P〈0.05）,模型校正后的决定系数（R2adj）为0.933。内部样本验证表明,发光菌抑制率的预测值与试验值相对偏差最大为8.6%,说明该模型具有较好的预测能力。机理分析显示,Cu2＋和Zn2＋交互体现为拮抗作用,Cd2＋和Cr3＋交互体现为协同作用,故在重金属复合污染控制方面,有必要进一步研究Cu2＋和Zn2＋拮抗作用对降低复合毒性的贡献。

Toxicity Effects of Extraction Solutions of Soil Doped with Heavy Metals to Photobacterium phosphoreum T3

Toxicity effects of composite pollution of heavy metals to Photobacterium phosphoreum were studied through determining the inhibition rate of Photobacterium phosphoreum in the extraction solutions of soil doped with Pb2+,Zn2+,Cd2+,Cu2+ and Cr3+.The response relation [Y=(-39.596±15.811)-(6.633±0.802)×(-lgXCu)(-lgXZn) +(59.466±8.731)×(-lgXCd)(-lgXCr)] was developed between concentration of Pb2+,Zn2+,Cd2+,Cu2+ and Cr3+ in extraction solutions of soil and the inhibition rate of Photobacterium phosphoreum based on the uniform experimental design,with the principle of equivalent-effect concentration ratio method and the multiple stepwise regression.The model had significant goodness-of-fit with advantages in F-test and t-test(P<0.05) and a high adjusted correlation coefficient(R2adj=0.933).The results in the internal sample validation indicated that the maximum of relative deviation between experimental and calculated values of the inhibition rate was 8.6%.The mechanism analysis showed that the interaction between Cu2+ and Zn2+ was antagonistic effect;while the interaction between Cd2+ and Cr3+ was synergistic effect.The findings of this study underlined the necessity of further research on the antagonistic effect between Cu2+ and Zn2+ to reduce composite toxicity in heavy metal pollution control.