自然环境中微塑料样品的采集与分离方法

综述了自然环境中微塑料样品采集与分离方法的研究进展,介绍了水环境、土壤与沉积物、环境空气、生物体等不同介质中微塑料的采集方法、技术原理和使用条件,以及密度分离、筛选分离、滤膜过滤等分离提取和预处理方法,提出了建立统一的微塑料采样指南,开展空气中微塑料富集、采样、分离和检测标准方法研究等建议。     

环境中微塑料的定量分析方法研究进展

从数量浓度和质量浓度2种不同的量化角度,对现有的微塑料定量分析方法（目检法、光谱法和热分析法）进行了系统梳理和综合阐述,其中,目检法操作简便但准确度低,光谱法准确度高但耗时过长,热分析法简便快速但不利于溯源分析。在系统综述的基础上,对未来需要深入研究的方向作了分析和展望。     

泥沙水样中微塑料纤维的分离与泥沙去除研究

建立了一种泥沙水样中分离微塑料纤维和去除泥沙的方法。选取聚酰胺6(Polyamide 6,PA)、丙烯腈-丁二烯-苯乙烯共聚物(Acrylonitrile butadiene styrene copolymers,ABS)、聚丙烯(Polypropylene,PP)颗粒,制备长度(1±0. 25) mm,宽度(200±30)μm的微塑料纤维;分别混合不同质量(0,0. 01,0. 05,0. 25,1. 25,6. 25 g)经30%过氧化氢消解和饱和氯化钠(1. 2 g/m L)、碘化钠溶液(1. 8 g/m L)浮选后的自然泥沙;以探究在不同泥沙质量下,静置阶段投加氯化钠颗粒对玻璃漏斗中微塑料纤维分离效率以及泥沙去除率的影响,并与不投加氯化钠和容量瓶浮选法作比较。结果表明,在静置阶段添加氯化钠颗粒效果较优,对3种微塑料纤维的平均分离效率和泥沙的平均去除率分别为87. 78%和98. 33%。实验结论可为微塑料分离提取方法的优化提供参考。     

环境中微塑料检测分析方法研究进展

概述了目前较为常见的微塑料检测方法,包括目检法、光谱分析法和热分析法,归纳分析了各种方法的技术进展、研究成果及优缺点,指出微塑料形状、大小、聚合物种类等方面的定性、定量分析尤为重要,能够为微塑料污染防治、溯源和影响评估提供依据.通过对现有方法的调研总结,提出多种检测分析方法联用将成为研究微塑料的发展方向,未来仍需要改进现有技术或者开发新的检测方法,结合图像处理、深度学习、计算机视觉等手段,缩短识别时间,提高检测精度,进而为微塑料污染防治工程提供技术支撑.     

环境中土壤微塑料研究热点及趋势可视化研究

为探究微塑料的研究现状、热点及趋势,以Web of Science核心合集数据库及中国知网(CNKI)数据库为数据来源,利用CiteSpace等软件绘制作者及机构共现网络图谱、区域分布特征图谱、关键词共现网络图谱和参考文献共被引图谱等,对环境微塑料尤其是土壤微塑料的研究现状及热点进行可视化分析。结果表明:微塑料研究自2016年开始逐步加强,其中土壤微塑料的研究热度在2021—2022年迅速上升;对于土壤微塑料,丰度分布、污染机制和健康风险等是当前研究的热点;完善土壤微塑料检测方法体系,探寻合适的土壤微塑料污染治理和管控方法及对策,对于维护生态安全和保障人体健康具有重要意义。     

垃圾渗滤液中微塑料分析的消解方法评价

微塑料(MPs)是近年来国内外关注度极高的新兴污染物,建立实际环境样品中MPs的分析方法是开展相关研究的基础。对于复杂污水样品而言,样品的消解过程至关重要,将极大地影响MPs的准确分析。选择垃圾渗滤液为典型复杂污水样品,采用样品浊度和色度变化、残余悬浮固体量、MPs在颗粒物中的占比为评价指标,对盐酸消解、30%过氧化氢消解及芬顿试剂消解3种常用消解方法的消解效果进行了比较。结果表明,30%过氧化氢对垃圾渗滤液样品的消解效果最佳,MPs在全部颗粒物中的占比达63.7%,极大地缩减了后续MPs定性分析的时间,降低了分析难度,且对渗滤液中MPs的回收率也高达(103±3)%。在此基础上,讨论了消解效果与过氧化氢投加量/样品浊度(V_H2O2/T₁)的关系。当V_H2O2/T₁为0.15～0.20 mL/NTU时,样品残余悬浮固体量最低,消解效果最佳。     

土壤微塑料监测技术现状及方法标准化建议

系统梳理土壤微塑料监测全过程技术方法,包括样品采集和制备、识别与定量、质量保证与质量控制(QA/QC)等环节,比较各方法优缺点,探讨土壤中微塑料监测方法标准化措施,建议完善土壤微塑料监测全过程QA/QC,制定涵盖全流程的监测技术规范,有序建立针对不同监测目标的分析方法标准体系,为土壤微塑料的监测与评估提供技术支撑。     

环境中的微塑料：赋存、检测及其危害

近年来,由个人护理品及废旧塑料直接或间接产生的微塑料不断地在各种环境介质中被检出,且微塑料会对生态系统产生各种危害,因此对微塑料的研究受到越来越广泛的关注。阐述了微塑料在水体、沉积物、沙滩和生物体中的赋存情况,介绍了微塑料的采集与分离方法,以及定性与定量分析方法。指出微塑料对环境及生物体产生的危害,提出现阶段研究存在的主要问题,并对今后的研究方向进行了展望。     

典型污水处理厂微塑料赋存特征研究

于2021年对镇江市3家典型污水厂水样开展微塑料调查,采用电子显微镜和拉曼光谱仪对水样进行检测分析.结果表明:样品中检出14种微塑料,其中聚乙烯(PE)占比在40％左右,聚丙烯(PP)、聚苯乙烯(PS)、聚对苯二甲酸乙二醇酯(PET)等的占比在5％～40％,尼龙(PA)、聚碳酸酯(PC)、聚甲醛(POM)、聚甲基丙烯酸...     

分子光谱技术在水体微塑料监测中的应用

水域、陆地和空气中的微塑料污染不仅对人们赖以生存的生态系统有潜在危害,而且对人类的身体健康存在持续性危害。针对这些污染问题开展研究的首要任务之一就是需要鉴定微塑料的成分,从而明确可能产生污染的源头以及引起污染的途径。分子光谱技术是鉴别微塑料最常用的分析方法之一,尤其是红外光谱法和拉曼光谱法。建立了基于分子光谱技术的水体微塑料检测方法,可实现对水体中1～5 000μm尺寸范围内的微塑料的自动化测试。其中,尺寸大于10μm的微塑料颗粒物可以通过显微红外光谱仪进行检测,尺寸大于1μm的微塑料颗粒物可以通过显微拉曼光谱仪进行检测。该方法操作简单、检测速度快、结果呈现直观,可作为微塑料检测的有力工具。     

典型湖泊水华特征及相关影响因素分析

通过2011-2015年对太湖、巢湖和滇池水华高发季节的连续监测,以藻类密度和水华面积为判据评价了3个湖体的水华情况及变化趋势,探讨了水华发生的主要影响因素。结果表明：太湖水华程度以\"轻度水华\"为主,巢湖水华程度以\"轻微水华\"为主,滇池水华程度以\"中度水华\"为主;太湖、巢湖和滇池水华规模均以\"零星性水华\"为主;太湖和巢湖藻类密度与水温、pH、溶解氧、总氮、总磷和高锰酸盐指数均呈显著正相关,与透明度呈显著负相关,与氨氮无显著相关性;滇池藻类密度与水温、总磷和高锰酸盐指数均呈显著正相关,与透明度和氨氮呈显著负相关,与pH、溶解氧和总氮无显著相关性。     

珠江广州段水体微塑料的分布特征及迁移规律

全球海洋塑料污染日益严重,河流是陆地产生的微塑料向海洋传输的重要渠道。珠江微塑料的入海通量排名处于世界前列,其中流经广州市区的虎门入海口的贡献量远高于其他入海口。为探究珠江广州段支流水体微塑料的污染现状并厘清其影响因素,文章对珠江广州段(包括支流和入海口)18个典型采样点位的表层水体微塑料进行了综合分析。结果显示,微塑料的污染丰度为0.123~25.2个/m³。微塑料的主要类型包括聚乙烯、聚丙烯、聚苯乙烯等,其占比远高于其他类型微塑料。珠江广州段接收广州市区及周边城市排放的生活、农业和工业废水,其中纤维主要来自纺织品的洗涤,聚乙烯和聚丙烯均为生活中的常用塑料,聚苯乙烯和聚丙烯多用于生产各类塑料产品(如塑料玩具、泡沫箱等)。在4类监测断面(点)中,入境断面和监控断面的微塑料丰度远高于背景点和入海口。流经人口密集、城市化程度高的区域的支流微塑料丰度远高于其他支流,入海口微塑料丰度最低。可见,人类活动是影响微塑料在不同河段分布的最主要因素。     

Distribution of Heavy Metals in Surface Sediments from an Antarctic Marine Ecosystem

The concentrations of lead, cadmium, copper,chromium, iron, manganese and zinc in surfacesediments collected from Potter Cove, in the 25de Mayo Island (King George Island), Antarctica, andits drainage basin, were measured by atomic absorptionspectroscopy. The obtained results were use todetermine the areal and vertical distribution of themetals of in the Cove and potential sources of thesemetals to this environment. The geochemical datasuggest that most of the metals found in Potter Coveconstitute a redistribution of autochthonous materialswithin the ecosystem. Therefore, the metalconcentrations can be considered to be present atnatural background levels in surface sediments.     

Impact of Channelization on Oyster Production: A Hydrodynamic-Oyster Population Model for Galveston Bay, Texas

A hydrodynamic-oyster population dynamics model was developed to assess the effect of a change in ship channel configuration under different freshwater inflow regimes and different future hydrologies on oyster (Crassostrea virginica) populations in Galveston Bay, Texas. The population dynamics model includes the effects of environmental conditions, predators, and the oyster parasite Perkinsus marinus on oyster populations. The hydrodynamic model includes the effects of wind stress, river runoff, tides, and oceanic exchange on the circulation of the Bay. Simulations were run for low, mean, and high freshwater inflow conditions under the present (1993) hydrology and predicted hydrologies for 2024 and 2049 that include anticipated water diversion projects to satisfy the freshwater demands of population growth in metropolitan Houston, Texas. Simulation results show that oyster biomass was predicted to increase after enlargement of the ship channel. Oyster biomass is expected to increase on about 53% of total reef acreage when averaged over a 50-yr time span. Oyster reef acreage characterized by increased biomass after channel enlargement increases moderately under the present hydrology and the 2049 hydrology, but decreases slightly in 2024. Lower biomass in 2024 is due to reduced freshwater inflow and increased saltwater intrusion that pushes the optimal areas for oyster growth somewhat farther upbay than in 2049. Declines in oyster biomass, noted in most simulations in downbay reaches, were more than balanced by increased oyster biomass upbay. The differential between upbay and downbay reefs can be explained by an increase in mortality from Perkinsus marinus downbay and saltwater intrusion upbay that expands the area characterized by moderate salinities. The 20th century history of Galveston Bay is one of expansion of isohaline structure and increased oyster production as a result of anthropogenic modification of bay physiography. The salinity gradient of the 1990s, however, is not in equilibrium with the distribution of hard substrate required for oyster growth, that reflects an earlier equilibrium with the pre-1900s hydrodynamics. Increased saltwater intrusion is normally disadvantageous to oyster populations; but, in this case, channel enlargement further expands the salinity gradient upbay and outward (east and west) from the channel. As a result, in most years, oyster biomass is increased because moderate salinities cover more of the pre-1900s reef tracts where hard substrate is plentiful.     

Development of a Provisional Physical Habitat Index for Maryland Freshwater Streams

Provisional physical habitat indices were developed and validatedfor Maryland Coastal and Non-Coastal Plain streams using variables (commonly called metrics) that best discriminated reference and degraded conditions based on biological, chemicaland land use data from the 1994–97 Maryland Biological Stream Survey (MBSS). These habitat indices contained variables that described structural, hydrological, vegetative and aesthetic components of stream habitat. Variables with the best discriminatory power for Coastal Plain streams were: instream habitat, velocity/depth diversity, pool/glide/eddy quality, embeddedness, maximum depth and aesthetic rating. Physical habitat variables with the best discriminatory power for Non-Coastal Plain sites were: instream habitat, velocity/depth diversity, riffle/run quality, embeddedness, number of rootwads and aesthetic rating. The overall classification efficiency forindex validation was 76% for both indices pooled over both strata. Scaled physical habitat index values (0–100) for bothstrata identified nearly twice as many good sites (31%) as very poor sites (16%). More than half the Maryland sites werein the poor to fair range (53%).     

C/N ratio and fossil pigments in sediments ofsome Estonian lakes: an evidence of human impact andHolocene environmental change

The content of carbon (C), nitrogen(N), fossil carotenoids (TC) and chlorophyllderivatives (CD) in the sediments of five Estonianlakes was analysed. Historical records of man-inducedchanges on catchments were used for the interpretationof the obtained data. On the basis of the C/N ratiosit was estimated that the planktonic matter formed ca.25% (C/N ratio 24) to 90% (C/N ratio 8) of theorganic pool matter of lake sediments. In eutrophicLake Ruusmäe the fraction of the phytoplanktonproduced in lakes was highest, amounting toapproximately 80–95% of the deposited organic matter.Remarkable C/N changes were noted in the sedimentsfrom lakes Matsimäe and Viitna, where the contentof planktonic matter has increased during lastdecades, reflecting an increase in recreationalactivity around these lakes. The variations in pigmentconcentrations in the sediments of lakes Matsimäeand Ruusmäe could be explained by changes in theland-use that have altered the intensity of primaryproduction and conditions of TC and CD degradationbefore the final burial.     

Metal Pollution Assessment of Sediment and Water in the River Hindon, India

The metal pollution in water and sediment of the River Hindon in western Uttar Pradesh (India) was assessed for Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. The metal concentrations in water showed wide temporal variation compared with bed sediment because of variability in water discharge and variations in suspended solid loadings. Metal concentrations in bed sediments provided a better evaluation of the degree and the extent of contamination in the aquatic environment, Santagarh and Atali being the most polluted sites of the river. The ratio of heavy metals to conservative elements (Fe, Al, etc.) may reveal the geochemical imbalances due to the elevated metal concentrations normally attributed to anthropogenic sources. Metal/Al ratios for the bed sediments of the river Hindon were used to determine the relative mobility and general trend of relative mobility occurred Fe > Mn > Zn > Cr > Ni > Pb > Cu > Cd.