ICP-MS在环境分析中的质谱干扰及其消除

针对环境领域20个无机元素的ICP-MS分析,总结了同量异位素、氧化物和双电荷、多原子离子等质谱干扰,探讨了影响质谱干扰的因素,提出了消除或降低每个元素质谱干扰的方法:选取合适的同位素、编辑校正方程、选择合适的模式、设置合理的等离子条件等,为建立ICP-MS相关环境标准方法提供参考。     

气相分子吸收光谱法测定水中氨氮干扰因素的研究

气相分子吸收光谱法测定成分复杂氨氮实际样品时,干扰因素造成测定结果不准确,而现有的标准方法和文献对干扰物质的研究不全面,制约了仪器的应用。该文系统地开展干扰因素的研究,提出干扰因素的消除方法,用加标回收率验证消除的有效性。结果表明,亚硫酸盐、硫化物等还原性物质对测定产生负干扰;石油烃、N,N-二甲基甲酰胺(DMF)等挥发性有机物、有机胺类以及亚硝酸盐对测定产生正干扰。根据不同干扰类型,通过加入适量酸性重铬酸钾溶液、在酸性条件下加热煮沸、预蒸馏等方法可消除干扰,消除干扰后加标回收率为84%~120%。生活污水、石化企业废水等6种典型水样消除干扰后,气相分子吸收光谱法和纳氏试剂分光光度法测定氨氮有较好的可比性,干扰消除方式有效。     

监测仪器使用中的电干扰及其防止

随着环境科学的发展,环境监测数据的资料已成为国家制定规划和立法的重要依据。因此,保证监测数据的可靠性就显得极为重要。以往我们注意的大多是化学方面引起干扰。本文着重介绍了由电引起的干扰(以下所指的干扰均为电干扰)以及防止方法,希望能引起监测人员的重视。 一、干扰和干扰源 所谓干扰,即有用信号以外的噪声或造成恶劣影响的变化部分的总称。干扰来自干扰源,在人们生活的环境中存在着各种各样的干扰源。通常干扰又分为外部干扰和内部干     

环境内分泌干扰物的作用机理及其生物检测方法

环境污染物的内分泌干扰问题近年来引起了极大的关注,大量研究工作集中于对环境内分泌干扰物的作用机理及其生物检测方法的研究。在总结国内外相关研究的基础上,对环境内分泌干扰物的类型及其主要作用机理进行了概括总结;对环境内分泌干扰物的体外生物检测方法的最新研究进展给予了评述;并对环境内分泌干扰物检测技术在环境中的应用进行了探讨;指出有关环境内分泌干扰物作用机理研究的成果能直接导致新的生物检测方法的发展,丰富了环境内分泌干扰物的检测技术类型。     

用火焰原子吸收法测定镀铬泥渣中的铁、镍、铜、锌、铅

我们曾对镀铬泥渣中铬的原子吸收测定进行了研究,本文重点研究镀铬泥渣中Fe、Ni、Cu、Zn、Pb测定时共存元素的干扰及其消除方法。 实验证明,大量Ni、Si的存在严重干扰铁的测定,大量Cu的存在严重干扰Ni的测定。采用标准加入法以消除Ni对Fe的干扰;采用沉淀法,萃取法分离铁与镍;在标液中加入等量铜来消除大量铜对测定镍的干扰,都难免繁琐费时。本文采用加入十二烷基硫酸钠或柠檬酸作干扰抑制剂,消除了大量铜对镍及大量硅对铁、锌测定的干扰;用降低乙炔流量,提高火焰温度的方法消除了二倍量的镍对铁测定的干扰,拟定了用火焰原子吸收法,不经分离直接测定镀铬废水处理后的泥渣中铁、镍、铜、锌、铅的测定程序。样品分析精密度均小于±4％,铁、镍、铜、铅的标准加入回收率为96—106％,锌为90—115％,用于实际样     

铁——EDTA络合滴定法

本文报告了以磺基水杨酸为络合滴定指示剂、在酸性介质中用EDTA溶液进行总铁的测定。试验了20余种阳离子和8种阴离子对铁测定的干扰情况,发现Cu~(2+)、Al~(3+)、Bi~(3+)、Sb~(3+)对测定有一定的干扰,并提出了消除Cu~(2+)、Al~(3+)、Ni~(2+)干扰的分离方法。F~-亦干扰铁的测定。     

水和废水中阴离子表面活性剂测定干扰因素试验研究

对二氮杂菲萃取分光光度法测定水和废水中阴离子表面活性剂的主要干扰因素进行了试验研究.设计了温度过低、浑浊带色和混溶乳化3种干扰试验方案,探讨了各干扰因素在不同工况下的试验结果、影响程度及消除措施.提出温度过低须在测定前提高环境温度,以确保显色反应完全;浑浊带色须在测定中采用色(浊)度校正法消除干扰;混溶乳化可在测定中利...     

沼泽湿地水生无脊椎动物完整性指数构建与健康评价

依据2017年5、7、9月对三江平原19处沼泽湿地(参照湿地6处,受损湿地13处)的水生无脊椎动物采样结果,应用生物完整性理论和方法,构建水生无脊椎动物完整性指数,评价三江平原沼泽湿地健康状况。通过对27个候选指标的分布范围、判别能力和相关性分析,筛选出总分类单元数、扁卷螺科百分比、龙虱科百分比、刮食者百分比4个指标构成水生无脊椎动物完整性指数核心指标。采用比值法计算各指标参数值,将各参数值加和得到水生无脊椎动物完整性指数值。根据参照湿地水生无脊椎动物完整性指数值的25%分位数值确定评价标准,对小于25%分位数的值进行三等分,确定三江平原沼泽湿地健康评价标准:≥2.58,无干扰;1.72～2.58,轻度干扰;0.86～1.72,中度干扰;0～0.86,重度干扰。结果表明:所调查的三江平原沼泽湿地有78.95%受到不同程度的干扰(其中47.37%受到了中重度干扰),21.05%属于无干扰。     

环境糖皮质激素受体干扰物的研究进展

综述了糖皮质激素受体干扰物的作用机制和生态效应,列举了多种活性筛选方法,并根据性质对干扰物进行了种类的划分。在当前环境糖皮质激素受体干扰物研究的基础上,指出了作用机制的研究不全面、个体生物筛选方法匮乏、缺少可信的活性模拟预测技术等问题,并提出了应借助模式生物完善作用机制研究,在此基础上建立稳定、高通量的个体生物活性筛选方法和动力学过程模拟替代技术用以活性预测等发展方向。     

氯酸钠对废水COD测定的干扰研究

氯酸钠是污水处理厂处理污水时常用的一种氧化剂,会对COD的测定产生负干扰。有的污水处理厂对含过量氯酸钠的污水未进行处理而直接外排;也有的污水处理厂为逃避环保部门的监管,在外排口投入过量氯酸钠,干扰COD测定,人为降低污水COD测定值。因而,研究氯酸钠对废水COD测定的干扰具有重要的现实意义。通过对标准样品和实际样品进行检测,发现氯酸钠对COD测定的干扰程度(真实值与测定值的差值)随着氯酸钠浓度的增加而增大。当氯酸钠浓度在100~1 000 mg/L范围内时,干扰值的大小与氯酸钠浓度呈显著正相关(P<0.05,r=0.997 4),且相同浓度氯酸钠对不同浓度COD测定产生的干扰无显著性差异。从追踪反应过程中不同形式氯元素含量的角度,进一步探究了氯酸钠对COD测定的干扰机理,发现氯酸钠对COD测定的干扰来自两个反应过程,分别是氯酸钠在消解过程中与还原性物质的反应、未完全反应的氯酸钠在滴定过程中与硫酸亚铁铵的反应,并且两个反应过程都会对COD的测定产生负干扰。根据干扰机理,研究建立了干扰校正方法,即校准曲线法。此方法具有较好的精密度和正确度,可以满足实际废水样品的测定要求。     

Disparate perceptions about uncertainty consideration and disclosure practices in environmental assessment and opportunities for improvement

The need to better address uncertainties in environmental assessment (EA) is well known, but less known is how those involved in, or affected by, EA processes understand and perceive uncertainties and how uncertainties are considered and disclosed. Based on a survey of 77 Canadian EA practitioners, regulators, and interest groups, this paper explores uncertainties in the EA process, uncertainty consideration and disclosure in EA practice and decision-making, and opportunities for improved disclosure. Nearly 80% of participants indicated that all EAs contain uncertainty; however, uncertainty disclosure was described as poor. Only 15% indicated that uncertainties are sufficiently acknowledged in practice and, when disclosed, considered by decision makers. Perceptions about uncertainty differed significantly between those who conducted EAs compared to those potentially affected by development, suggesting that either communication about uncertainty is poor, or participants' understandings about what is considered ‘good’ practice are very different. Almost half of the participants believe that there is overconfidence in impact predictions and mitigation measures, and the majority indicated that if uncertainties were more openly reported then EA would be a better tool for informing decisions. Most participants did not believe that EAs that openly disclose uncertainties lack credibility; and contrary to proponents' tendencies to limit disclosure, participants perceived limited risk of disclosure in terms of project approval. The majority of participants did not believe that there was sufficient guidance available on how to report uncertainties, or on how to use that information in decision-making. Results indicate a substantial need to better understand how uncertainties are viewed and dealt with in EA; the importance of uncertainty disclosure and consideration in EA; and the risks and benefits of uncertainty disclosure to proponents, decision makers, and the public. We identify several opportunities for improving the practice of uncertainty consideration and disclosure.     

Avoiding climate change uncertainties in Strategic Environmental Assessment

This article is concerned with how Strategic Environmental Assessment (SEA) practice handles climate change uncertainties within the Danish planning system. First, a hypothetical model is set up for how uncertainty is handled and not handled in decision-making. The model incorporates the strategies ‘reduction’ and ‘resilience’, ‘denying’, ‘ignoring’ and ‘postponing’. Second, 151 Danish SEAs are analysed with a focus on the extent to which climate change uncertainties are acknowledged and presented, and the empirical findings are discussed in relation to the model. The findings indicate that despite incentives to do so, climate change uncertainties were systematically avoided or downplayed in all but 5 of the 151 SEAs that were reviewed. Finally, two possible explanatory mechanisms are proposed to explain this: conflict avoidance and a need to quantify uncertainty.     

Cokriging optimization of monitoring network configuration based on fuzzy and non-fuzzy variogram evaluation

A number of optimization approaches regarding monitoring networkdesign and sampling optimization procedures have been reported inthe literature. Cokriging Estimation Variance (CEV) is a usefuloptimization tool to determine the influence of the spatial configuration of monitoring networks on parameter estimations. Itwas used in order to derive a reduced configuration of a nitrateconcentration monitoring well network. The reliability of the reduced monitoring configuration suffers from the uncertainties caused by the variographer's choices and several inherent assumptions. These uncertainties can be described considering thevariogram parameters as fuzzy numbers and the uncertainties by means of membership functions.Fuzzy and non-fuzzy approaches were used to evaluate differencesamong well network configurations. Both approaches permitted estimates of acceptable levels of information loss for nitrate concentrations in the monitoring network of the aquifer of the Plain of Modena, Northern Italy. The fuzzy approach was found torequire considerably more computational time and numbers of wellsat comparable level of information loss.     

A multicriteria analytical framework for sustainability evaluation under methodological uncertainties

Multicriteria analysis is widely used to perform sustainability evaluation for purposes such as decision making or progress assessment following a chosen sustainable development concept. The stages of multicriteria analysis include indicator selection, data characterization, normalization, weighting, and aggregation. However, due to the various framings of sustainability, non-equivalent approaches could be adopted at each stage, introducing methodological uncertainty. Consequently, depending on the methods chosen, divergent and conflicting conclusions or decisions may result. This paper addresses the issue of methodological uncertainties in sustainability evaluation by analyzing how methodological uncertainties arise during multicriteria analysis, then proposing an analytical framework that employs uncertainty and sensitivity analyses to quantify and manage the effects of methodological uncertainties. The consideration of methodological uncertainties in the structure of multicriteria sustainability evaluation shifts the analysis from deterministic to probabilistic, which is advantageous to arrive at robust and homogenized sustainability conclusions or decisions.     

微小流量大气采样器自动检定装置的研究

介绍了微小流量大气采样器自动检定装置的检测原理 ,给出了该检定装置用于计算的数学模型 ,主要通过对各分量标准不确定度进行分析和计算 ,得到该检定装置测量的扩展不确定度 ,并证明建立该自动检定装置适用于微小流量大气采样器的检定工作     

Fragmentary provisions for uncertainty disclosure and consideration in EA legislation,regulations and guidelines and the need for improvement

The consideration and disclosure of uncertainties is fundamental to a credible EA process, but little is known about the nature and type of requirements and guidance available to proponents, practitioners and decision makers about how to deal with uncertainties. This paper examines the provisions for considering and disclosing uncertainties in EA. Methods are based on a comparative review of uncertainty provisions in EA legislation, regulations and guidance documents under Canadian federal, provincial and territorial jurisdictions. Results show 10 types of provisions applied at different stages of the EA process with considerable jurisdictional variability and incoherence. The most common provision was that decision makers can request that project proponents provide more information, followed by the preparation of contingency plans, and that practitioners document their assumptions about data reliability. Most of these provisions were found in guidelines, versus legislation or regulations; and most addressed impact management, with very few provisions for addressing uncertainty during EA review and decision making. Current practices of uncertainty (non)disclosure and (non)consideration in EA can be explained, in part, by the superficial nature and limited extent of the requirements and guidance made available to EA practitioners, proponents, and decision makers. The existing requirements placed on proponents and practitioners to disclose and consider uncertainties are necessary, but insufficient. Stronger, more coherent and transparent requirements for those tasked with EA review and decision making to consider uncertainty information when disclosed, and the development of practical guidance on how to do so, are needed.     

An Inexact Fuzzy-robust Two-stage Programming Model for Managing Sulfur Dioxide Abatement Under Uncertainty

In this study, an inexact fuzzy-robust two-stage programming (IFRTSP) method is developed for tackling multiple forms of uncertainties that can be expressed as discrete intervals, probabilistic distributions and/or fuzzy membership functions. The model can reflect economic penalties of corrective measures against any infeasibilities arising due to a particular realization of system uncertainties. Moreover, the fuzzy decision space can be delimited into a more robust one with the uncertainties being specified through dimensional enlargement of the original fuzzy constraints. A management problem in terms of regional air pollution control has been studied to illustrate the applicability of the proposed approach. Results indicate that useful solutions for planning the air quality management practices have been generated. They can help decision makers identify desired pollution-abatement strategy with minimized system cost and maximized environmental efficiency.     

Uncertainty assessment of mapping mercury contaminated soils of a rapidly industrializing city in the Yangtze River Delta of China using sequential indicator co-simulation

Accurate characterization of heavy-metal contaminated areas and quantification of the uncertainties inherent in spatial prediction are crucial for risk assessment, soil remediation, and effective management recommendations. Topsoil samples (0–15 cm) (n = 547) were collected from the Zhangjiagang suburbs of China. The sequential indicator co-simulation (SIcS) method was applied for incorporating the soft data derived from soil organic matter (SOM) to simulate Hg concentrations, map Hg contaminated areas, and evaluate the associated uncertainties. High variability of Hg concentrations was observed in the study area. Total Hg concentrations varied from 0.004 to 1.510 mg kg⁻¹ and the coefficient of variation (CV) accounts for 70%. Distribution patterns of Hg were identified as higher Hg concentrations occurred mainly at the southern part of the study area and relatively lower concentrations were found in north. The Hg contaminated areas, identified using the Chinese Environmental Quality Standard for Soils critical values through SIcS, were limited and distributed in the south where the SOM concentration is high, soil pH is low, and paddy soils are the dominant soil types. The spatial correlations between Hg and SOM can be preserved by co-simulation and the realizations generated by SIcS represent the possible spatial patterns of Hg concentrations without a smoothing effect. Once the Hg concentration critical limit is given, SIcS can be used to map Hg contaminated areas and quantitatively assess the uncertainties inherent in the spatial prediction by setting a given critical probability and calculating the joint probability of the obtained areas.     

原子荧光光度法同时测定水中砷、硒的不确定度分析

对原子荧光光度法测定水样中砷、硒浓度的影响因素进行分析,对各因素的不确定度进行计算和评估。结果表明,影响其测量不确定度主要因素是原子荧光强度值带来的不确定度,其它因素是次要的。     

Optimal Expansion Strategy for a Sewer System under Uncertainty

Because of fast urban sprawl, land use competition, and the gap in available funds and needed funds, municipal decision makers and planners are looking for more cost-effective and sustainable ways to improve their sewer infrastructure systems. The dominant approaches have turned to planning the sanitary sewer systems within a regional context, while the decentralized and on-site/cluster wastewater systems have not overcome the application barriers. But regionalization policy confers uncertainties and risks upon cities while planning for future events. Following the philosophy of smart growth, this paper presents several optimal expansion schemes for a fast-growing city in the US/Mexico borderlands—the city of Pharr in Texas under uncertainty. The waste stream generated in Pharr is divided into three distinct sewer sheds within the city limit, including south region, central region, and north region. The options available include routing the wastewater to a neighboring municipality (i.e., McAllen) for treatment and reuse, expanding the existing wastewater treatment plant (WWTP) in the south sewer shed, and constructing a new WWTP in the north sewer shed. Traditional deterministic least-cost optimization applied in the first stage can provide a cost-effective and technology-based decision without respect to associated uncertainties system wide. As the model is primarily driven by the fees charged for wastewater transfer, sensitivity analysis was emphasized by the inclusion of varying flat-rate fees for adjustable transfer schemes before contracting process that may support the assessment of fiscal benefits to all parties involved. Yet uncertainties might arise from wastewater generation, wastewater reuse, and cost increase in constructing and operating the new wastewater treatment plant simultaneously. When dealing with multiple sources of uncertainty, the grey mixed integer programming (GIP) model, formulated in the second stage, can further allow all sources of uncertainties to propagate throughout the optimization context, simultaneously leading to determine a wealth of optimal decisions within a reasonable range. Both models ran for three 5-year periods beginning in 2005 and ending in 2020. The dynamic outputs of this analysis reflect the systematic concerns about integrative uncertainties within this decision analysis, which enable decision makers and stakeholders to make all-inclusive decisions for sanitary sewer system expansion in an economically growing region.