寒区土壤重金属迁移转化与修复治理研究进展

A review of heavy metal migration transformation and remediation in cold region soils

随着寒区资源开发和工程建设规模逐渐扩大,将导致过量重金属持续进入冷生土壤圈中,进而影响寒区土壤生态环境。本文通过文献回顾,对寒区土壤重金属物质来源与排放、空间分布、迁移规律、转化机制以及修复与治理等五个方面进行梳理。寒区土壤重金属受人类活动影响显著,其中,工业排放、交通运输、矿业开发以及农业活动等是寒区土壤重金属的重要来源;重金属在土壤中具有不同分布特征且容易发生迁移,主要取决于人类活动和土壤母质两种因素,且土壤性质、重金属自身特性和外部环境等因素也对重金属分布和迁移转化有一定作用;重金属进入土壤对土壤质地、土壤温度、土壤水文以及植被等可以造成不同程度的影响,虽然固化稳定、生物炭和淋洗等修复方法可以用于部分寒区土壤重金属污染修复,但需要考虑季节性温度变化对修复效果的影响。因此,鉴于重金属对寒区土壤生态环境影响显著,未来研究仍需要继续加强对寒区土壤重金属监测和安全风险评估并进行及时、必要、积极的修复治理,以防止过量重金属进入寒区并对寒区土壤环境造成危害。

With the gradual expansion of the scale of resource development and engineering construction in the cold region,it will lead to the continuous entry of excessive heavy metals into the cold biosphere,which in turn will affect the soil ecological environment in the cold region.In this paper,we review five aspects of soil heavy metal sources and emissions,spatial distribution,migration patterns,transformation mechanisms,and remediation and treatment in cold regions through literature review.Soil heavy metals in cold regions are significantly affected by human activities,among which industrial emissions,transport,mining development and agricultural activities are important sources of soil heavy metals in cold regions.In addition,natural factors also have important contributions to the content of heavy metals in soil,mainly including permafrost degradation and soil weathering.Heavy metals have different distribution characteristics in the soil and are easy to migrate,which mainly depends on two factors,human activities and soil parent material,the nature of the soil,the properties of the heavy metals themselves and the external environment also play a role in the distribution and migration of heavy metals,Soil properties and characteristics of heavy metals themselves mainly affect the distribution and migration of local heavy metals.The climate environment can make heavy metals carry on long-distance transmission,and then affect the distribution and migration of heavy metals.Heavy metals entering the soil can have different degrees of influence on soil texture,soil temperature,soil hydrology and vegetation,etc.However,there are currently limited research findings on the remediation of heavy metals in cold region soils.Although remediation methods such as solidification and stabilization,biochar and drenching can be used for remediation of heavy metal contamination in some cold-region soils,the influence of seasonal temperature changes on the remediation effect needs to be considered.In view of the impact of heavy metals on the ecological environment of cold-region soils and the difficulty in the remediation of soil heavy metal pollution,future research needs to continue to strengthen the monitoring of heavy metals in cold-region soils,safety risk assessment and timely and necessary remediation and treatment,in order to prevent excessive heavy metals from entering the cold region and causing harm to the cold-region soil environment.