长江下游富镉土壤元素分布特征及其污染修复试验

在江苏长江沿岸一带新发现了大片富镉土壤,局部地段已经出现了蔬菜样品镉含量超标的重金属污染现象。笔者通过对江苏沿江富镉土壤元素地球化学特征的初步分析,探讨了引起局部土壤Cd污染的主要原因与特点,系统介绍了在南京八卦洲受Cd污染的蔬菜地开展现场重金属污染土壤修复与调控试验的主要研究资料与结果,发现施用适量的钙镁磷肥、石灰等固定剂对于降低蔬菜中的Cd含量有明显成效,为长江下游富Cd土壤区蔬菜安全生产提供了新的思路。

Element distribution characteristics of Cd-rich soils and their pollution remediation test in the lower reaches of the Yangtze River

A large tract of Cd-rich soils is found along the lower reaches of the Yangtze River in Jiangsu and the Cd content in vegetable samples is found to be in excess of standards in some areas. Based on a preliminary analysis of the element geochemical characteristics of Cd-rich soils in the study area, the authors discuss the main cause for the local Cd pollution in soils and systematically introduce the main research data and results of heavy metal-polluted soil remediation and control tests performed in vegetable lands polluted by Cd in Baguazhou, Nanjing. It is found that the Cd concentration within vegetable can be significantly reduced by applying an appropriate quantity of fixation agents such as calcium-magnesium phosphate (Ca, Mg)3(PO4)2] fertilizers. This study provides a new idea for safe vegetable production in areas of relatively Cd-rich soils in the lower reaches of the Yangtze River.