离子色谱法同时测定土壤中可溶性Na^、K^＋、Mg^2＋、Ca^2＋

应用离子色谱法（IC）同时测定土壤中可溶性Na^、K^＋、Mg^2＋、Ca^2＋。以CS12A阳离子交换柱分离,稀硫酸为淋洗液,电导检测器检测,对土壤中的Na^、K^＋、Mg^2＋、Ca^2＋进行同时测定。方法具有较宽的线性范围和较高的灵敏度。在0～40mg／L内呈良好的线性关系,土壤中Na^、K^＋、Mg^2＋、Ca...     

乌鲁木齐市采暖季空气质量变化趋势分析

为了定量评价乌鲁木齐市采暖季空气污染近五年的治理成效,给环境治理决策提供科学依据,运用回归分析方法,对乌鲁木齐市采暖季空气质量的浓度、级别和变化规律进行回归分析。分析结果表明,PM10、SO2、NO2三项污染物的浓度都有所下降,空气质量级别的污染天数呈现明显的月变化规律。乌鲁木齐市采暖季空气的重污染状况有所遏制,但SO2污染凸现,在下一步的治理工作中,加强尘污染治理的同时要加大对SO2的治理力度。     

街谷地区CO污染现状分析

本文分析了典型街谷地区ＣＯ污染的现状及其浓度的垂直分布和水平分布的变化情景。由监测结果可知,街谷地区ＣＯ浓度是较高的,而且峰值出现在采暖期。     

生物过滤技术在大气污染控制中的应用

生物过滤是控制大气污染的经济有效技术,具有较好的发展前景。本文介绍了生物过滤技术处理废气的研究,应用历史,现状,和生物过滤理论,分析了工艺的使用范围,设计及运行控制要点,列举了应用的范例。     

离子色谱法测定饮用水和面包中的溴酸根

选用ＡＳ９－ＨＣ高容量阴离子交换色谱柱,不需处理除去干扰离子,可直接进样。测定了两种水样,其中一种检出溴酸根,方法检出根０．００５ｍｇ．１＾－１水样加标回收率９１．３－９３．４％。采用全新的自动化样品处理技术－加速溶剂萃取萃取面包中的溴酸根。经ＡＳ９－ＳＣ阴离子交换色谱柱分离,选择最佳淋洗条件。电导检测,方法检 ０．０７ｍｇ．１＾－１,对十二种市售包进行测定,均未检出溴酸根,样品加标回收率７９．９     

大气污染指示植物的研究

自50年代以来.为寻找一种经济、实用和灵敏的方法来监测环境变化,开展了大量大气污染指示植物的研究.这些工作包括用植物叶片典型症状、树皮、草本植物、附生植物指示气体污染(O_3、PANs、NO_x、SO_2、HF、乙烯等)、粉尘以及重金属污染.进入80年代以后,有关研究集中到利用植物富集的污染物含量结合计算机等先进技术指示和监测大气环境变化及进行大气质量评价.本文对国内外开展的大气污染指示植物研究的历史及其主要方法作了简要介绍,并就利用植物指示和监测大气污染的若干问题进行了探讨.     

The application of generalized linear mixed models to multi-level sampling for insect population monitoring

Iwao's quadratic regression or Taylor's Power Law (TPL) are commonly used to model the variance as a function of the mean for sample counts of insect populations which exhibit spatial aggregation. The modeled variance and distribution of the mean are typically used in pest management programs to decide if the population is above the action threshold in any management unit (MU) (e.g., orchard, forest compartment). For nested or multi-level sampling the usual two-stage modeling procedure first obtains the sample variance for each MU and sampling level using ANOVA and then fits a regression of variance on the mean for each level using either Iwao or TPL variance models. Here this approach is compared to the single-stage procedure of fitting a generalized linear mixed model (GLMM) directly to the count data with both approaches demonstrated using 2-level sampling. GLMMs and additive GLMMs (AGLMMs) with conditional Poisson variance function as well as the extension to the negative binomial are described. Generalization to more than two sampling levels is outlined. Formulae for calculating optimal relative sample sizes (ORSS) and the operating characteristic curve for the control decision are given for each model. The ORSS are independent of the mean in the case of the AGLMMs. The application described is estimation of the variance of the mean number of leaves per shoot occupied by immature stages of a defoliator of eucalypts, the Tasmanian Eucalyptus leaf beetle, based on a sample of trees within plots from each forest compartment. Historical population monitoring data were fitted using the above approaches.     

Visualization and localization of bromotoluene distribution in Hedera helix using NanoSIMS

Some plants are known as indoor air purifiers. A large number of studies report kinetic purification results for an extensive panel of plants, i.e. the pollutant concentration (volatile organic compounds, as known as VOC, most of the time) is continuously monitored by gas chromatography. However, only a few papers describe the mechanisms involved in such processes. This study deals with the use of secondary ion mass spectrometry imaging as an efficient tool to locate atmospheric pollutant as bromotoluene within the Hedera helix plant (leaf, roots) and the substrate on which it was previously grown. Hedera helix plants have been placed in a pollution chamber with control of the exposure parameters. Plant and soil samples excised were transferred into a fixative solution of glutaraldehyde and paraformaldehyde for a few days, were dehydrated using ethanol and were embedded with resin. Cross sections were made from the pale brown solids obtained. Then, a device using a cathodic pulverization device capable of depositing a few nanometers of gold atoms over the sample was used to make the surface electronically conductive for the NanoSIMS. Hence, polluted and unpolluted samples of Hedera helix and substrates were obtained following a careful procedure that allowed for the discrimination between polluted and nonpolluted ones. Nanoscale spatial resolution was an invaluable tool (NanoSIMS) to achieve this, and proved that VOCs, such as bromotoluene, were actually trapped by plants such as Hedera helix.     

Factors influencing on the bioaccessibility of polybrominated diphenyl ethers in size-specific dust from air conditioner filters

Size-specific concentrations and bioaccessibility of polybrominated diphenyl ethers (PBDEs) in dust from air conditioner filters were measured, and the factors influencing the PBDE bioaccessibility were determined. Generally, the PBDE concentrations increased with decreasing dust particle size, and BDE209 (deca-BDE) was generally the predominant congener. The bioaccessibility ranged from 20.3% to 50.8% for tri- to hepta-BDEs, and from 5.1% to 13.9% for BDE209 in dust fractions of varied particle size. The bioaccessibility of most PBDE congeners decreased with increasing dust particle size. The way of being of PBDE (adsorbed to dust surface or incorporated into polymers) in dust significantly influenced the bioaccessibility. There was a significant negative correlation between the tri- to hepta-BDE bioaccessibility and organic matter (OM) contents in dust. Furthermore, tri- to hepta-BDE bioaccessibility increased with increasing polarity of OMs, while with decreasing aromaticity of OMs. The tri- to hepta-BDE bioaccessibility significantly positively correlated with the surface areas and pore volumes of dust. Using multiple linear regression analysis, it was found that the OM contents and pore volumes of dust were the most important factors to influence the tri- to hepta-BDE bioaccessibility and they could be used to estimate the bioaccessibility of tri- to hepta-BDEs according to the following equation: bioaccessibility (%) = 45.05 − 0.49 × OM% + 1.79 × pore volume. However, BDE209 bioaccessibility did not correlate to any of these factors.     

天然沸石床处理受污染景观水体的试验

采用天然沸石滤床对富营养化景观湖水进行净化试验,结果表明,天然沸石滤床能有效地净化受污染的湖水,CODCr、氨氮、总磷和浊度的去除率分别为35.8%、95.0%、66.7%和78.0%,沸石能有效地去除水中的氨氮,其作用机理包括离子交换和生物硝化两种作用。