干旱区污染绿洲土壤中Cd和Zn形态分布与生物有效性  

Form distribution of Cd,Zn and bioavailability in arid contaminated oasis soil

作　　者：杨一鸣[1,2] 南忠仁[1] 赵转军[1] 王胜利[1] 

机构地区：[1]兰州大学资源环境学院西部环境教育部重点实验室,兰州730000 [2]西北民族大学化学工程学院,兰州730030

出　　处：《兰州大学学报（自然科学版）》2010年第1期59-64,共6页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(40671167;40671179);国家环境保护公益性项目(200809098);国家重点基础研究发展计划(973计划)项目(2008CB417212)

摘　　要：利用盆栽试验研究了干旱区污染绿洲土壤中Cd和Zn形态分布与生物有效性。结果表明:少量的Cd和Zn有促进油菜生长的作用,但高质量分数的Cd和Zn对油菜的生长有明显抑制作用;原状绿洲土壤中Cd和Zn形态以残渣态为主,随着绿洲土壤中Cd和Zn污染程度的加深,Cd和Zn各形态分布发生了显著变化,其中碳酸盐结合态Cd和Zn和铁锰氧化物结合态Cd和Zn质量分数大幅增加,并逐渐占据绝对优势,而残渣态Cd和Zn质量分数则几乎不变。相关分析表明土壤中的铁锰氧化物结合态Cd质量分数与油菜叶和根部的Cd质量分数呈极显著相关,表明土壤中的铁锰氧化物结合态Cd对油菜叶和根部累积Cd有最大贡献;铁锰氧化物结合态Zn和有机物结合态Zn分别与油菜根部和叶部的Zn质量分数呈极显著相关,表明土壤中铁锰氧化物结合态Zn和有机物结合态Zn分别对油菜根和叶部累积Zn贡献最大;油菜叶和根部Cd的富集系数均大于Zn的,表明油菜吸收Cd的能力大于Zn的;两种金属的富集系数叶部的均大于根部的,表明Cd和Zn的迁移性较强,且Cd在油菜中的迁移能力大于Zn的,其毒害作用也相应大于Zn的。两种金属主要累积在油菜可食用的叶部,因此对人体健康有潜在威胁。Pot experiment was conducted to study the distribution of cadmium, zinc fractionations and their availability to the rape in arid oasis soil in northwest China. The result showed that lower concentrations of Cd and Zn could promote rape growth, but higher concentrations could obviously inhibit rape growth. Cd and Zn fractionations in the uncontaminated oasis soil existed almost in the residual fractionation, but with Cd and Zn pollution degree rising in the oasis soil, Cd and Zn fractionations distribution changed significantly, in which carbonate-bound and Fe-Mn oxide-bound Cd and Zn concentrations were significantly increased and gradually occupied the absolute superiority; however, the residual Cd and Zn concentrations were almost unchanged. The significant correlation was found between Fe-Mn oxide-bound Cd concentration and Cd concentration in rape leaves and roots, which showed that Fe-Mn oxide-bound Cd made the greatest contribution to Cd accumulation in rape leaves and roots. Similarly, there was a significant correlation between Fe-Mn oxide-bound Zn and organic-bound Zn concentrations and concentrations in rape leaves and roots, respectively, suggesting that Fe-Mn oxide-bound Zn and organic-bound Zn made the greatest contributions to Zn accumulation in rape leaves and roots, respectively. The Bio-concentration Factors （BCF） of Cd in rape leaves and roots were all greater than Zn, which showed that the uptake capability of Cd in the rape was greater than Zn; moreover, the BCFs of the two metals in leaves were greater than in roots, which showed that Cd and Zn had the stronger migration capability and the transferring capability of Cd in the rape was greater than Zn. Also, the toxic effect of Cd was greater than Zn, and the two metals mainly accumulated in the edible leaves. Therefore, Cd and Zn present potential risks to human health.

关 键 词：污染 绿洲土壤 Cd和Zn形态 生物有效性 

分 类 号：S153[农业科学—土壤学] X53[农业科学—农业基础科学]