农田土壤—植物系统中钒的迁移富集规律

Migration and enrichment patterns of vanadium in the soil and plant system of farmland

钒(V)是维持生物体正常生命活动的必需微量元素之一,也是联合国环境规划署列入环境优先污染物的有害元素之一。研究V在土壤—植物系统中的迁移富集规律,对于深入了解其生态地球化学行为、保障农产品安全与人体健康具有重要现实意义。本文以山东临沂某地普通农田为例,对土壤、植物进行系统的采样,分析测试土壤与植物中的V与伴生元素的含量。采用描述性统计、相关性分析、聚类分析等统计方法与单因子污染指数法、潜在生态风险指数法、生物富集系数法等分析方法对研究区内V进行来源分析、污染评价以及V在土壤—植物系统的迁移转换规律的研究。结果表明:V在研究区内分布较为集中,其含量随着Fe、Ti含量的升高而升高,随SiO_(2)、Na_(2)O、Sr、CaO含量升高而下降。研究区内V主要来源于母岩风化,高含量部分与磁铁矿相关。根据单因子指数法与潜在生态风险指数法评价结果,V在研究区土壤内较为清洁,但区内伴生的Cd污染需引起注意。V在植物中主要富集在根部,植物对V的吸收能力总体上与土壤中Cu、Pb、Zn、Ni、Co、Cd、Cr的含量呈负相关,以Cr最为显著;与土壤中As的含量呈正相关。该研究丰富了V的生态地球化学理论,也为区域农业生产、环境质量评估和生态污染防治提供了科学依据。

Vanadium(V)is an essential trace element required by organisms for maintaining their normal life activities.It is also a harmful element listed as a priority environmental pollutant by the United Nations Environment Programme(UNEP).The study of the migration and enrichment patterns of V in the soil and plant system is of great practical significance for further understanding the ecological geochemical behavior of V and ensuring the safety of agricultural products and human health.This study systematically sampled the soil and plants in some ordinary farmland in Linyi City,Shandong Province and analyzed and tested the contents of V and its associated elements in the soil and plant samples.Moreover,this study conducted the source analysis and pollution assessment of V and investigated the migration and transformation patterns of V in the soil-plant system using statistical methods such as descriptive statistics,correlation analysis,and cluster analysis,as well as the single factor pollution index method,the potential ecological risk index method,and the biological enrichment coefficient method.The results are as follows:V is relatively concentrated in the study area,and its content increases with an increase in the Fe and Ti contents and decreases with an increase in the SiO_(2),Na_(2)O,Sr,and CaO contents;The V in the study area mainly originates from the weathering of parent rocks,and the parts with a high V content is related to magnetite;As shown by the results of the single factor index method and the potential ecological risk index method,V is relatively clean in the soils of the study area,but attention should be paid to the pollution of the associated Cd;V is enriched primarily in the roots of plants,and plants'absorption capacity of V is generally negatively correlated with the contents of Cu,Pb,Zn,Ni,Co,Cd,and especially Cr in soils and is positively correlated with the As content in soils.This study enriches the ecological geochemical theory of V and provides a scientific basis for regional agricultural production,environmental quality assessment,and ecological pollution control.