基于土壤重金属污染和累积性评价的耕地环境质量类别划分与风险管控  

Classification and Risk Management of Cultivated Land Environmental Quality Based on Evaluation of Soil Heavy Metal Pollution and Accumulation

作　　者：张传华[1] 刘力[1] 代杰 李曼曼 张凤太 邓凌[3] ZHANG Chuanhua;LIU Li;DAI Jie;LI Manman;ZHANG Fengtai;DENG Ling(College of Management,Chongqing University of Technology,Chongqing 400054,P.R.China;Chongqing Jiangjin District Work Committee of Chinese Peasants and Workers Democratic Party,Chongqing 402218,P.R.China;Chongqing Socialist College,Chongqing 400064,P.R.China)

机构地区：[1]重庆理工大学管理学院,重庆400054 [2]中国农工民主党重庆市江津区工作委员会,重庆402218 [3]重庆社会主义学院,重庆400064

出　　处：《生态环境学报》2025年第2期311-320,共10页Ecology and Environmental Sciences

基　　金：国家社会科学基金重点项目(20AJY005);重庆市社科规划一般项目(2022NDYB80);2023年重庆市教育委员会人文社会科学研究规划一般项目(23SKGH256)。

摘　　要：以重庆彭水县大同镇为例,协同采集土壤-玉米样品50套,分析土壤及玉米样品中Cd、Hg、As、Pb和Cr的含量及土壤pH,综合考虑土壤重金属污染及累积性,开展耕地土壤环境质量类别划分,提出风险管控措施建议,以期为地质高背景区耕地土壤风险管控提供技术方法。结果表明,研究区耕地土壤以安全利用类和严格管控类为主,土壤存在明显重金属累积的点位占比为22%,主要的超标及累积因子为Cd和As,土壤重金属污染及累积问题显著。研究区耕地土壤环境质量类别以III类(安全利用类,无明显累积)为主,IV类(安全利用类,有明显累积)和VI类(严格管控类,无明显累积)耕地均分布在研究区西南部。研究区耕地土壤重金属超标整体受地质背景的影响,重金属累积主要与城镇生活污水、禽畜粪肥和部分复合肥施用等人为活动有关,由于外源输入,部分耕地土壤超标程度加剧趋势明显。研究区玉米样品的总体超标率为28%,超标因子为Cd。当土壤pH>6.5时,农产品超标风险显著降低。建议在耕地土壤重金属溯源断源的基础上,根据土壤及农产品污染程度,施用钙质土壤调理剂或钙镁磷肥进行土壤酸化治理,实现“边生产,边修复”,逐渐改善研究区土壤环境质量状况。Soil serves as the foundation for grain production and is an important cornerstone for national economic development.In recent years,owing to human activities and the geological background of certain regions,soil heavy metal pollution has become increasingly severe.Heavy metals are highly mobile in the environment,are easily absorbed by crops,enter the food chain,and pose a threat to human health.Effective risk management of contaminated farmlands is crucial to ensure food security.According to the“Environmental Quality Standards for Soils of Agricultural Land-Risk Control Standards for Soil Pollution(Trial)”(GB 15618-2018),farmland soils are classified and managed based on their total heavy metal content.The“Guidelines for the Remediation and Management of Contaminated Agricultural Land”(NY/T 3499-2019)stipulate that for safe-use farmland,pollution source control should be prioritized before remediation efforts.Thus,the primary approach to managing soil pollution risks in farmlands involves classifying environmental quality,tracing and eliminating pollution sources,and implementing pollution remediation.Studies have shown that soil heavy metal pollution is concealed,cumulative,and originates from diverse sources influenced by factors such as the geological background and human activities.Therefore,excessive heavy metal levels in farmland soils do not necessarily indicate exogenous pollution.Conversely,even if soil heavy metal concentrations are within limits,the presence of nearby pollution sources poses potential ecological risks owing to their accumulation.Currently,the classification of farmland soil environmental quality in many regions of China is based on soil pollution characteristics,neglecting the accumulation of soil heavy metals due to potential pollution sources.This oversight makes it difficult to accurately determine whether farmland soil is contaminated by exogenous sources during subsequent risk management,which affect precise source tracing and elimination.Therefore,managing the risk of

关 键 词：耕地 重金属污染 累积性评价 环境质量类别划分 

分 类 号：X53[环境科学与工程—环境工程] X825