高锰酸钾预氧化强化处理受污染的水库水

考察了高锰酸钾强化常规工艺处理受污染水库水效能．进行生产性试验对比了投加高锰酸钾前后处理水浊度、颗粒物、CODMn及藻类的去除效果,并对高锰酸钾强化除污染的可能作用机制进行了探讨。结果表明：投加高锰酸钾使得澄清池平均出水浊度由4．490NTU降低至3．995NTU;出厂水平均浊度由0．670NTU降低至0．463NTU;颗粒物去除率由71．72％提高至83．86％;澄清池出水平均CODM。由3．21mg／L降低至2．86mg／L;出厂水平均CODM。由2．99mg／L降低至2．62mg／L;藻类总数去除率由36．49％提高至71．27％．且藻类种属也相应减少。高锰酸钾能有效地强化受污染水库水中不同污染物的去除效能,显著地提高出水水质。     

秸秆焚烧期间空气中细颗粒的组分特征

分析并探讨了南京市秸秆焚烧期间细颗粒中水溶性阴离子和铵,有机碳(OC)和元素碳(EC),以及Cu、Zn、Pb、Si等38种元素的含量和浓度.结果表明:细颗粒( PM2.5)水溶性离子中硫酸根浓度最高,其次是铵根离子,硝酸盐和氯离子,氟离子和亚硝酸盐最低.秸秆焚烧期间细颗粒样品中离子含量占26％,Si元素和金属所占份额为...     

居民经手口途径摄入含PAHs颗粒物的致癌风险评价

为评价居民经手口途径暴露于被PAHs污染室外土壤和室内灰尘颗粒的致癌风险以及与之相关各个参数的重要程度,本文构建了经手口途径暴露于这两种颗粒物的概率风险模型,运用蒙特卡罗模拟方法评价了居民的致癌风险,探究了主要的风险来源及关键的暴露参数.结果表明,幼儿、儿童和青少年所承受的风险较大;婴儿、成年人和老年人较小.婴儿致癌风险超过10~(-6)的概率为2%左右;幼儿和青少年超过10~(-6)的概率在5%左右,但不超过10~(-4);儿童超过10~(-6)的概率在15%左右,有0.1%左右的概率超过10~(-4);成年人和老年人超过10~(-6)的概率分别在1%和0.1%左右.室内灰尘颗粒是主要的风险来源,占91%左右;室内硬表面灰尘是室内致癌风险的主要来源,占65%左右.与致癌风险相关性最大的因素为:手口途径发生的频次(FQ)、灰尘颗粒中PAHs的等效斜率(PEFj)、灰尘在室内硬表面的含量(DSLHS)、颗粒物从手掌皮肤表面到口腔的转移率(SE)和灰尘在室内软表面的含量(DSLSS).     

2013年1月中国中东部大气重污染期间上海颗粒物的污染特征

2013年1月,我国中东部地区连续遭受多场大范围、长时间、高强度的灰霾天气.期间,本研究采用在线连续观测手段测量了上海市城区大气中气态污染物、颗粒物的质量浓度、细颗粒物的化学组分等,获得了高污染过程中颗粒物的污染特征.观测结果显示,1月份期间PM₁₀、PM_2.5与PM_1.0平均浓度分别为(125±75) μg·m^-3、(82±54) μg·m^-3和(44±27) μg·m^-3,PM_2.5/PM₁₀为65.0%±13.0%,能见度小于10.0 km的累计时间长达284 h,占整月小时数的38.2%.灰霾期间大气PM_2.5中SO₄^2-、NO₃^-、NH₄⁺和OM分别占PM_2.5的21.5%±4.9%、22.8%±5.9%、15.9%±3.1%和20.4%±4.3%,其中,二次组分(SNA+SOA)占PM_2.5的65.7%±8.4%,表明灰霾期间二次组分对PM_2.5的贡献较大;灰霾期间还测得较高的SOR和NOR,分别为0.335±0.121和0.229±0.066,说明SO₄^2-和NO₃^-的生成效率较高;较高的/比值(1.137±0.438)表明灰霾期间机动车的污染较明显.研究发现,随着PM_2.5质量浓度不断地增加,SNA的比例明显上升,期间NH₄⁺对SO₄^2-、NO₃^-等酸性物质的中和发挥了重要作用.研究结果显示,灰霾期间,因受低温和高浓度颗粒物的影响,上海地区的大气对有机物的氧化能力明显减弱,昼夜OC/EC值差别不大.     

全生物降解地膜原料颗粒对土壤性质、小麦生长和养分吸收转运的影响

全生物降解地膜是解决白色污染问题的有效途径之一,但其对土壤-植物系统的影响尚不清楚.为全生物降解地膜大面积应用的安全性评价提供依据,采用盆栽试验研究了全生物降解地膜原料颗粒种类（H、 S和X）和用量(2.5、 10和40 g·kg^-1)对土壤理化性质、生物学性质及植物生长和养分吸收转运的影响.结果表明,3种全生物降解地膜原料颗粒显著提高土壤pH,但对土壤有机质含量影响不显著,H地膜颗粒中高用量和S地膜颗粒低中用量时对土壤硝化作用及土壤氮的有效性有积极作用,而X地膜颗粒则表现为抑制作用;H地膜颗粒使土壤有效磷含量提高,S和X无显著影响;X地膜颗粒使土壤有效钾含量提高,S和H无显著影响. 3种全生物降解地膜颗粒对土壤酶活性的影响因地膜种类、用量和酶的类型的不同而异,随着地膜颗粒用量提高,3种土壤酶活性均呈现下降趋势.对小麦（Triticum aestivum L.）生长而言,除低中用量的S处理外,其余处理均抑制小麦的生长,其中X地膜颗粒对小麦根、茎叶和籽粒生物量抑制作用最大且随地膜颗粒用量提高小麦生物量抑制效果越明显.对小麦养分而言,在地膜颗粒低用量时促进氮吸收、高用...     

What have we known so far for fluorescence staining and quantification of microplastics: A tutorial review

• Fluorescence staining provides a fast and easy method to quantify microplastics. • Factors that influence staining are summarized to obtain an optimum staining effect. • Natural organic matter can be stained by dye and interfere with quantification. • Fluorescence staining is applied in both field and laboratory studies. • Future work involves developing new dyes and automated image-analysis methods. Understanding the fate and toxicity of microplastics (MPs,<5 mm plastic particles) is limited by quantification methods. This paper summarizes the methods in use and presents new ones. First, sampling and pretreatment processes of MPs, including sample collection, digestion, density separation, and quality control are reviewed. Then the promising and convenient staining procedures and quantification methods for MPs using fluorescence dyes are reviewed. The factors that influence the staining of MPs, including their physicochemical properties, are summarized to provide an optimal operation procedure. In general, the digestion step is crucial to eliminate natural organic matter (NOM) to avoid interference in quantification. Chloroform was reported to be the most appropriate solvent, and 10–20 μg/mL are recommended as optimal dye concentrations. In addition, a heating and cooling procedure is recommended to maintain the fluorescence intensity of MPs for two months. After staining, a fluorescence microscope is usually used to characterize the morphology, mass, or number of MPs, but compositional analysis cannot be determined with it. These fluorescence staining methods have been implemented to study MP abundance, transport, and toxicity and have been combined with other chemical characterization techniques, such as Fourier transform infrared spectroscopy and Raman spectroscopy. More studies are needed to focus on the synthesis of novel dyes to avoid NOM’s interference. They need to be combined with other spectroscopic techniques to characterize plastic composition and to develop image-analysis methods. The stability of stained MPs needs to be improved.     

A comparison of SEM-EDS with ICP-AES for the quantitative elemental determination of estuarine particles

Suspended particulate matter (SPM) is a key component regulating the biogeochemistry of natural and contaminant moieties in estuaries. Individual particle analyses can complement conventional bulk analyses of SPM, but are rarely undertaken. This study used scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDS) of particles to quantify a range of elements in the reference estuarine sediment PACS-2. This approach was compared with a bulk SPM analysis based on inductively coupled plasma-atomic emission spectrometry (ICP-AES). The median concentrations of Al, Fe, Mg, and Ca for the two approaches were similar, and accuracy for both methods was good. SEM-EDS analysis was also satisfactory for K. Agreement was poorer for Mn and Ti, which were present at trace concentrations. Increasing the number of particles examined by SEM-EDS should improve the analysis. SEM-EDS analysis of SPM from the Tamar Estuary, UK, revealed marked geochemical differences between particle sub-populations.Selected article from 6th European Meeting on Environmental Chemistry, Belgrade, 2005, organised by Prof. Dr. Branimir Jovancicevic and the European Association of Chemistry and the Environment (ACE, www.research.plymouth.ac.uk/ace)     

Line intersect sampling: Ell-shaped transects and multiple intersections

The probability of selecting a population element under line intersect sampling depends on the width of the particle in the direction perpendicular to the transect, as is well known. The consequence of this when using ell-shaped transects rather than straight-line transects are explicated, and modifications that preserve design-unbiasedness of Kaiser's (1983) conditional and unconditional estimators are presented. A case against treating multiple intersections as multiple probabilistic events is argued on the basis, also, of preserving design-unbiased estimation.     

大气中PM_(2.5)的现状分析及新的思考

PM2.5是对空气中直径小于或等于2.5μm的固体颗粒或液滴的总称,又叫细颗粒物或入肺颗粒物。为解除目前我国大部分地区灰霾天气的困扰并探索其形成原因,文章主要综述了PM2.5的形成、危害及防治措施。通常用PM2.5来表示每立方米空气中这种颗粒的含量,该值越高,就代表空气污染越严重。PM2.5对人体危害极大,其大小与相应疾病的发病率,死亡率成正比。空气中的PM2.5的浓度可以通过重量法等进行测量。以微生物过滤为辅助,降低工厂,汽车的废气,尾气排放从而减少PM2.5的污染,也可以增加生活环境中净化空气的绿色植被,利用静电除尘的方法来改善空气质量。     

重型柴油车对空气质量的影响及其排放的控制

通过对柴油车污染物排放的特征和机动车排放清单的分析,探讨了重型柴油车对我国城市空气质量的影响及其排放的控制.重型柴油车排放大量的氮氧化物和颗粒物,其中氮氧化物为大气中产生二次细粒子以及臭氧的重要前体物之一,导致区域性灰霾的形成,而柴油颗粒物是影响健康的一个主要有毒空气污染物,尤其是其中粒径为30～100 nm的超细粒子...