滨海湿地环境中微塑料表面性质及形貌变化  

Surface properties and changes in morphology of microplastics exposed in-situ to Chinese coastal wetlands

作　　者：周倩[1,2] 涂晨[1,2] 张晨捷 章海波[1,3] 付传城 李远 李连祯[1,2] 熊宽旭[1] 徐笠 骆永明[1,2,4] Qian Zhou;Chen Tu;Chenjie Zhang;Haibo Zhang;Chuancheng Fu;Yuan Li;Lianzhen Li;Kuanxu Xiong;Li Xu;Yongming Luo(Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation,Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences,Yantai 264003,China;Center for Ocean Mega-Science,Chinese Academy of Sciences,Qingdao 266071,China;Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province,School of Environmental&Resource Sciences,Zhejiang A&F University,Hangzhou 311300,China;Key Laboratory of Soil Environment and Pollution Remediation,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;Beijing Research Center for Agricultural Standards and Testing,Beijing Academy of Agriculture and Forestry Sciences,Beijing 100097,Chin)

机构地区：[1]中国科学院烟台海岸带研究所中国科学院海岸带环境过程与生态修复重点实验室,烟台264003 [2]中国科学院海洋大科学研究中心,青岛266071 [3]浙江农林大学环境与资源学院浙江省土壤污染生物修复重点实验室,杭州311300 [4]中国科学院南京土壤研究所中国科学院土壤环境与污染修复重点实验室,南京210008 [5]北京市农林科学院北京农业质量标准与检测技术研究中心,北京100097

出　　处：《科学通报》2021年第13期1580-1591,共12页Chinese Science Bulletin

基　　金：国家自然科学基金(41771351,41991330);中国科学院前沿科学重点研究项目(QYZDJ-SSW-DQC015);国家重点研发计划(2016YFC1402202)资助。

摘　　要：海岸带湿地是微塑料的重要聚集区.目前,对海岸带真实湿地土壤环境中微塑料表面形貌和性质变化研究甚少.本研究选取我国北方温带的黄河口盐沼湿地和南方亚热带的北部湾红树林湿地,以聚苯乙烯发泡和聚乙烯薄膜为受试微塑料对象,通过原位土壤掩埋(地下暴露)和非掩埋(地上暴露)定位试验和定期采样,观察和分析微塑料表面形貌、官能团、比表面积和疏水性等变化,以揭示南北典型生物地理海岸带湿地环境微塑料表面性质及形貌变化特征.在形貌上,南方北部湾红树林湿地中发泡微塑料表面出现更多的凹坑和孔洞,地上暴露的发泡18个月后,表面发生脆化和易脱落现象,而地下暴露的未出现此现象;对于比表面积,黄河口盐沼湿地原位土壤掩埋发泡和薄膜的更高;对于羰基指数,黄河口盐沼湿地土壤环境中发泡和薄膜表面的增长速率更快,地上暴露的微塑料更容易老化;对于表面疏水性,南北两类湿地土壤中掩埋薄膜表面疏水性均降低.对于微塑料类型,发泡和薄膜型微塑料均以大孔和介孔为主,发泡表面形貌更易发生变化,但薄膜比表面积变化更大.可见,滨海土壤环境微塑料表面性质及形貌变化与湿地类型及条件、微塑料种类及其暴露方式和时间等多因素有关,但对这些变化的机理有待深入研究.综上,本研究可为我国海岸带环境微塑料表面微界面化学过程和环境行为研究及其风险管控提供科学依据.Coastal wetlands are key areas of accumulation of microplastics.However,until now only a few studies have focused on the surface properties and morphological changes in microplastics in the real coastal wetland environment.Here,two typical biogeographic coastal soils,the Yellow River Estuary salt marsh wetland in the temperate zone and the Beibu Bay mangrove wetland in the subtropical zone,were selected for study.Polystyrene foams and polyethylene films were used and exposed within two coastal wetlands sites through in situ soil burial(underground exposure)and surface placement(above-ground exposure).The samples were sampled after 6,12,18 and 24 months of exposure to reveal the characteristics of the surface properties and morphological changes in microplastics in typical wetlands from the southern and northern biogeographic coastal zones.The surface morphology,microstructures and attached materials were observed using scanning electron microscopy using an energy dispersive spectrometer.Surface properties of the microplastics,i.e.the surface roughness,specific surface area,pore size distribution,functional groups and hydrophobicity,were analyzed by using atomic force microscopy,a surface area analyzer,a mercury porosimeter,Fourier transform infrared spectrometry and a contact angle meter.The surface morphology of the polystyrene foams in the Beibu Bay mangrove wetland exhibited more pits and holes than those in the Yellow River Estuary salt marsh wetland.The polystyrene foams exposed aboveground in the Beibu Bay mangrove wetland showed embrittlement and exfoliation after 18 months,while those exposed underground did not show such features.The specific surface areas of the polystyrene foams and the polyethylene films in the Yellow River Estuary salt marsh wetland were higher than those in the Beibu Bay mangrove wetland.The pore distributions on the surfaces of the two microplastic types mainly comprised macropores and mesopores.However,the porosity of the polyethylene film in the Yellow River Estuary salt marsh we

关 键 词：微塑料 盐沼 红树林 海岸带湿地 定位试验 表面变化 

分 类 号：X53[环境科学与工程—环境工程]