摘要
研究微塑料(microplastics,MPs)对稻田土壤-水界面中重金属空间分布和迁移的影响机制,可为微界面环境中MPs和重金属交互作用及生态风险评估提供理论支撑和科学依据。2021年7月对采自东北地区稻田的土壤添加不同浓度不同粒径的MPs,借助薄膜梯度扩散技术(DGT)在毫米尺度上获取稻田土壤-水微界面生物有效态重金属元素的原位高分辨信息,并根据Fick第一扩散定律评估不同MPs添加处理下重金属元素的迁移特征和释放通量。结果表明:(1)稻田土壤-水微界面生物有效态Mn、Co、Fe、Ni、Zn、Pb、Cu和Cd浓度在剖面上具有显著的空间分布差异;(2)MPs的添加显著降低了有效态Cu(-50.7%~8%,P<0.001)、Zn(-17.1%~-4.1%,P<0.001)和Cd(-16.7%~-2.2%,P<0.001)的浓度;(3)土壤MPs的添加改变了有效态Cu的迁移方向,使土壤由Cu源转化成Cu汇,说明MPs对Cu存在明显的吸附效应;(4)不同粒径MPs的添加对生物有效态Ni的影响差异较大,大粒径(80μm)MPs增加了其浓度,小粒径(10μm)则相反。
Research on the mechanisms of microplastics(MPs)on the spatial distribution and migration of heavy metals at the soil-water interface in paddy fields provides theoretical support and a scientific basis for studying the interaction between MPs and heavy metals at the micro-interface environment,as well as assessing the ecological risk.In July 2021,black soils from paddy fields in Northeast China were collected for a rice seedling culture experiment.The experimental treatments included fertilization and no fertilization,with four MP addition groups(SH,10 mm MP 40 g;SL,10 mm MP 4 g;BH,80 mm MP 40 g;BL,80 mm MPs 4 g)and a control group(CK)for each treatment.The experiment began on July 5th,2021,and lasted 73 days,with four replicates of each group.On the last day of the experiment,high-resolution in-situ information on bioavailable heavy metals at the paddy soil-water micro-interface was obtained at the millimeter scale using the diffusive gradient thin film(DGT)technique.The migration characteristics and release flux of heavy metals under the different MP treatments were evaluated based on Fick's first law of diffusion.Results show:(1)There were significant spatial distribution differences in the concentrations of bioavailable Mn,Co,Fe,Ni,Zn,Pb,Cu,and Cd at the soil-water micro-interface of paddy fields.(2)The addition of MPs significantly reduced the concentrations of bioavailable Cu(-50.7% to 8%,P<0.001),Zn(-17.1%to-4.1%,P<0.001),and Cd(-16.7% to -2.2%,P<0.001).(3)The addition of MPs to soil changed the migration direction of bioavailable Cu,transforming the soil from a source of Cu into a sink,indicating significant adsorption of Cu by MPs.(4)The impact of different MPs particle sizes on bioavailable Ni varied,with larger MP particles(80 mm)increasing Ni concentration and smaller MP particles(10 mm)decreasing Ni concentration.
作者
朱晓艳
王琪琛
姜懿真
武忠
柳钟惠
陈吉孝
王钰琳
袁宇翔
ZHU Xiao-yan;WANG Qi-chen;JIANG Yi-zhen;WU Zhong;LIU Zhong-hui;CHEN Ji-xiao;WANG Yu-lin;YUAN Yu-xiang(Key Laboratory of Songliao Aquatic Environment,Ministry of Education,Jilin Jianzhu University,Changchun 130118,P.R.China;State Key Laboratory of Black Soils Conservation and Utilization,Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences,Changchun 130102,P.R.China)
出处
《水生态学杂志》
CSCD
北大核心
2024年第3期10-20,共11页
Journal of Hydroecology
基金
吉林省自然科学基金(YDZJ202201ZYTS480,20240602034RC)
国家自然科学基金面上项目(42271129)
吉林省教育厅优秀青年项目(JJKH20240378KT)
黑土地保护与利用科技创新工程专项(XDA28100304)。
关键词
微塑料
土壤-水微界面
重金属
原位高分辨率信息
迁移特征
microplastics
soil-water interface
heavy metals
in-situ high-resolution bioavailability
migration characteristics
