含硫钝化剂对抑制芥菜Pb、Cd富集的效果研究

Effects of sulfur passivator on restraining Pb and Cd accumulations in Brassica juncea Cosson

以蔬菜中较为普遍的Pb和Cd污染为对象，以常用的钙镁磷重金属钝化剂为对照，进行不同用量含硫钝化剂对抑制芥菜Pb、Cd富集的效果研究。结果表明：钙镁磷和含硫钝化剂都能降低芥菜Pb、Cd富集量，幅度分别达到9．8％～44．0％、8．6％～21.1%，其中低量含硫钝化剂的降铅作用与钙镁磷相当，中高量含硫钝化剂的降镉作用与钙镁磷相当。含硫钝化剂用量与芥菜菜体铅、镉含量都呈显著负相关，其回归方程分别为YPb=10．332—1．122x（R^2=0．941^＊＊）和YCd=1．1573—0．055x（R^2=0．883^＊）。灰色关联分析表明：芥菜菜体Pb含量与土壤总Pb含量的关联度最大，关联系数为0．725，其次分别为土壤pH〉土壤有效铅。而芥菜菜体Cd含量与土壤有效Cd含量的关联度最大，关联系数为0．736，其次分别为土壤全量镉〉土壤pH。

The Pb and Cd contaminations, which commonly occur in vegetables, were used as the target to study the effect of sulfur passivators on Brassica juncea Cosson. The commonly applied calcium, magnesium, and phosphate heavy metal passivators were used as control to compared with the sulfur reagent. Experimental results indicated that the accumulated amounts of Pb and Cd in B. juncea Cosson decreased by 9.8%-44.0% and 8.6%-21.1%, respectively, when calcium, magnesium, phosphate and sulfur passivators were applied. On the passivators＇ effect of reducing Pb content in vegetable, the sulfur passivator in low dosage was equivalent to calcium, magnesium, or phosphate passivators. On Cd reduction, application of sulfur passivator with moderate and high dosages was almost same as calcium, magnesium, or phosphate counterparts. There was a significantly negative correlation between the contents of Pb and Cd in B. juncea Cosson and the dosage of sulfur passivator. Regression equations were YPb=10. 332--1. 122x （R^2 =0. 941^＊＊ ） and YCd=1. 1573-0. 055x （R^2 =0. 883^＊＊ ）. Gray correlation analy- sis showed that the correlation coefficient between Pb content in B. juncea Cosson and that in soil was the highest, i. e. , 0. 725. That between Pb in vegetable and soil pH was the next highest, and followed by that between Pb in vegetable and available Pb in soil. On the other hand, the correlation between Cd content in B. juncea Cosson and available Cd in soil was highest with a correlation coefficient of 0. 736. It was followed by the correlation between the Cd in vegetable and the total amount of Cd, and pH of soil.