摘要
为了解宁波浙贝母种植地土壤重金属分布特征,采用ICPAES测定了章水镇种质资源圃土壤Cd、Pb、Cu、Ni、Cr和Zn质量比,用Hkanson潜在生态风险指数法评价重金属的生态风险,BCR连续提取法分析其分布形态。结果表明,土壤中重金属元素总量从大到小排序为Zn、Cr、Pb、Cu、Ni、Cd,其中Cd富集程度最高,平均质量比为背景值的8倍左右,超过国家二级土壤标准。Eir指数表明,Cd的潜在风险指数也最高,75%区域处于很高或高潜在生态风险;RI指数表明,90%区域处于高潜在生态风险或中潜在生态风险。土壤中重金属均以残渣态为主,但Zn的弱酸提取态、Cu的可氧化态比例相对较高,Cd的3种可提取态相加接近45%,具有高潜在危害性。相关性分析表明,Cu和Zn、Cr和Ni,以及Cu和Cd重金属的来源具有相似性,且不同形态重金属之间可能会发生迁移转化。p H值与各种重金属的形态之间不存在明显的相关关系,有机质对重金属化学形态的影响因重金属种类不同而有差异。
To understand the distribution of heavy metal contents in the soil of fritillary cultivation area in Ningbo,Zhejiang,the paper has identified and measured the content rate of Cd,Pb,Cu,Ni,Cr and Zn in the garden soilsof the germ-plasma resources of a place named Zhangshuiby ICP-AES. It has also done assessments of the ecological risks associated with the heavy metal residue contents based on the Hkanson potential ecological risk indexes,with its distribution pattern being analyzed by using the BCR sequential extraction method. The total amount of the soil＇s heavy metal content rates can be shown in the following descending order： Zn〉 Cr 〉Pb〉 Cu 〉Ni〉 Cd. Among them,Cd has turned out to exhibit the highest rate of enrichment,whose average content rate stands about 8 times as that of the background data over the Second Grade of the contaminated soil in accordance with the national standard. The Eirindex indicates that the highest potential risk comes from the Cd content rate,which accounts for75% of the potential ecological risk of the region. The RI index also reveals that 90% of the region has been suffering high or moderate ecological risks,among which heavy metal contaminants mainly exist in the form of residue,whereas the acid extractable state of Zn and the oxidizable state of Cu is also rather high.What is more,the total proportion of the three types of extractable states for Cd has been found nearly 45%,signifying quitegreat potential hazard level,indeed. A comprehensive analysis has also confirmed that Cu and Zn,Cr and Ni,in addition to Cu and Cd,tend to come from similar origins,though it is possible for the heavy metal residents under action to migrate and turn into different forms of contaminantsin various ways. However,no significant correlation has been noticed between the p H value and the different forms of the heavy metal contents. Nevertheless,the effects of the organic matters on the chemical forms of heavy metals have been discovered in a great variety depending on the types of the heavy metals under study.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2017年第3期1171-1176,共6页
Journal of Safety and Environment
基金
国家自然科学基金项目(51408551)
浙江省公益技术应用研究计划项目(2016C33037
2015C33012
2017C33023)
宁波市科技计划项目(2016A610232
2015A610253
2017C50026)
国家级大学生创新计划项目(201710876005)
浙江省大学生科技创新项目(2017)
浙江省重中之重学科课题(CX2016014)
关键词
环境学
土壤
重金属
形态分析
污染评价
浙贝母
environmentalology
soil
heavy metal
speciation analysis
pollution evalution
Fritillaria thunbergii bulbus
