北方沿海某水稻田重金属污染特征及源分析

Pollution characteristics and source analysis of heavy metals in a paddy field in northern coastal area

我国耕地重金属污染情况日益严重,以北方沿海某农场为研究对象,采集水稻土测试重金属含量,分析其污染特征及来源。结果显示,该区域水稻土重金属污染严重,其中Cd元素含量远高于当地土壤背景值,通过对重金属空间统计分析,发现Cd、Hg、Zn在表层土壤中平均浓度高于下层土壤,在表层更易积累。而重金属累积多源于大气沉降、污水灌溉、有机肥等投入品的使用。通过对多种潜在输入源分析,发现现今灌溉水源污染影响较小,但曾经灌溉水源承载了大量工业废水,对水稻土可能造成一定污染,同时施用肥料、当地大气环境等均可加重水稻土重金属累积。本研究为当地水稻田重金属污染控制及修复治理提供了技术支撑。

The situation of heavy metal pollution in arable land in China is becoming increasingly serious.Taking a farm in Northern Coastal Area as the research object,the paddy soil was collected to detect the content of heavy metals,and the pollution characteristics and sources were analyzed.The results showed that the paddy soil in this region was seriously polluted by heavy metals,and the content of Cd was much higher than the background value of the local soil.Through the spatial statistical analysis of heavy metals,it was found that the average concentration of Cd,Hg and Zn in the surface soil was higher than that in the underlying soil,and they were more likely to accumulate in the surface.The accumulation of heavy metals is mainly due to the use of atmospheric subsidence,sewage irrigation,organic fertilizer and other inputs.Through the analysis of various potential input sources,it is found that the current irrigation water pollution has little influence,but the irrigation water once carried a large amount of industrial wastewater,which may cause certain pollution to paddy soil.Meanwhile,agricultural inputs and local atmospheric environment all aggravate the accumulation of heavy metals in paddy soil.This study provides technical support for the control and remediation of heavy metal pollution in local rice fields.