Monofluorinated analogues of polychlorinated biphenyls (F-PCBs): synthesis using the Suzuki-coupling, characterization, specific properties and intended use

An improved method, a palladium-catalyzed cross-coupling reaction the so-called Suzuki-coupling, was used to synthesize 19 monofluorinated analogues (F-PCBs) of polychlorinated biphenyls (PCBs), including analogues of PCBs 28, 52 and 81. The coupling of chlorinated and/or fluorinated isomers of aryl boronic acids with bromo- and/or iodobenzenes gave the desired F-PCB congeners in good to excellent yields. The self-coupling product of the aryl boronic acids was the major impurity, but this limitation could be minimized. The influence of ortho-substitution by chlorine on the reaction time was studied in detail. The F-PCBs were characterized by means of ¹H and ¹⁹F NMR and mass spectrometry (MS). F-PCBs show remarkably similar characteristics in many aspects to those of the corresponding non-fluorinated parent PCBs. Since fluorine is generally resistant to degradation, once incorporated into a substrate it functions as an indelible label that can be used to monitor structures and dynamics. F-PCBs may prove their usefulness as markers and tracers in mechanistic and toxicological studies. The aim of further research will be to test the suitability of fluorine as a sensitive probe in a broad range of applications, including synthesis, analytical, mechanistic and toxicological studies.     

Environmental regulation: A new approach

Environmental regulations traditionally have been developed to limit pollution emitted to a single environmental medium at a time. This approach has been followed for a variety of reasons—political, legal, and informational, to name a few. However, more efficient environmental management could be achieved if environmental standards were issued simultaneously across all media. In this way multimedia pollutant tradeoffs could be utilized and regulatory uncertainty could be reduced.     

GJB 151系列标准中电源线尖峰传导敏感度测试变化分析

从GJB 151系列标准的版本演变出发,梳理了CS106项目的发展轨迹。通过对比各版本中CS106项目的适用平台、测试方法、干扰信号特征等,得到了各版标准中该项目的主要差异。最后,结合美军461系列标准的发展变化,从四个方面分析了变化的原因,给出了电磁兼容标准建设发展的思考建议,为电磁兼容工程测试人员提供了参考。     

新兴污染物水环境保护标准及其实用型去除技术

近年来,在国内外的城市污水、地表水、饮用水中,频繁检出一些新兴污染物,严重威胁着生态安全和饮用水水质安全.传统的有机污染物综合指标,如化学需氧量(COD)、生化需氧量(BOD)等不能反映该类污染物的污染状况,也不能完全代表水质状况,因此建立控制新兴污染物的水环境保护标准十分必要.另外,从众多研究的去除技术中识别出高效、经济、可行的实用型去除技术对实际污水处理厂去除新兴污染物的意义重大.本文主要分析与介绍国内外有关新兴污染物的水环境保护标准现状,并基于发达国家的实际案例,总结了针对新兴污染物的一些实用型去除技术,以期对相关水环境保护标准的制定起到推动作用,并为后续污水处理厂的升级改造提供技术支持.     

水源地生态补偿标准动态测算模型及其应用

为响应政府号召、提供水源地保护环境经济手段支撑,在对现有生态补偿标准核算方法研究总结的基础上,提出水源地生态补偿标准动态测算模型,并应用于鹤地水库水源地生态补偿标准测算中.水源地生态补偿标准动态测算模型是把生态补偿过程分为试行?修复?稳定3个阶段,根据阶段特点及目标的不同,采用相应的测算方法：试行阶段采用条件价值评估法,修复阶段采用基于总成本修正模型和水资源价值法的博弈模型,稳定阶段采用水质污染赔偿法.结果显示,鹤地水库生态补偿试行阶段期限为2015年~2017年,补偿标准总额为14.4亿元;修复阶段期限为2018~2020年,补偿标准总额为89.4亿元;稳定阶段为2021年后,需每年计算补偿标准.水源地生态补偿标准动态测算模型实现了生态补偿标准核算的动态化,且该模型采用的具体核算方法认可度高?应用广泛?计算简单,便于推广.     

A modified toxicity testing method using tropical marine microalgae

Toxicity testing of four heavy metals(Cd, Cu, Mn and As) using four species of tropicalmarine phytoplankton, Chaetoceros calcitrans, Isochrysis galbana, Tetraselmis tetrahele and Tetraselmis sp., was carried out in multiwellplates with test volumes of 2 mL and the resultscompared to those of standard, large volume,shake-flasks. IC₅₀ values (concentrations of metalsestimated to inhibit 50% growth relative to thecontrol) were determined after 96 hours based onautomated O.D. readings measured in Elisa microplatesby a Multiskan spectrophotometer. Good agreement wasachieved between O.D. readings and cell countsindicating that this new method is a simple,economical, practical and rapid technique for toxicitytesting, and provides good reproducibility of IC₅₀ values. Results of the toxicity testsindicate that Cu was the most toxic metal (averageIC₅₀ values ranging from 0.04 to 0.37 mg L^-1), followed by Cd (0.06–5.7 mg L^-1), Mn (7.2–21.4 mg L^-1) and As (33.9–319.3 mg L^-1).Test species had different degrees of sensitivity tothe metals tested, with I.galbana and C. calcitrans the mostsensitive to Cu, Cd and Mn. Based on these findingsit is recommended that the existing Malaysian InterimStandards for Marine Water Quality for Cd and Cu be reviewed.     

环境监测技术的现状及发展趋势

根据日本环境质量标准发展的需求,结合欧洲新近实施的相关环境标准,分析了环境监测技术需求和发展方向.     

Renewable energy from gasification of manure: an innovative technology in search of fertile policy

After describing an innovative technology, the close-coupled gasification and cyclonic combustor, this article explores the policy issues that inhibit a superior sustainable solution fromflourishing. Discussion of technology includes defining biomass,explaining what biomass to energy means, what the advantages of biomass to energy are, and why gasification is a superior biomassto energy technology. Specifically the environmental benefits ofalternatives to landspreading of traditional manure management arediscussed, as well as the advantages of gasification versus traditional combustion techniques for high nitrogen fuels. The policy environment is explored, particularly regarding sustainability, manure management, and renewable energy. Artificial, non-sustainable barriers to renewable energy, and the impact of wide jurisdictional variability are discussed. North Carolina is identified as a unique jurisdiction to monitor because of its high volume of livestock manure, and laggard position in renewable energy advocacy. The authors contend that these two positions are unsustainable, and that pressures can beexpected to force the state to modify its renewable energy policies or risk losing market share in livestock production tomore pro-sustainable policy oriented states.     

国家环境标准样品在环境有机污染物分析中的应用

简介了在分析环境中的有机污染物时,标准样品作为替代物、基体加标物在样品前处理中的应用,及其作为仪器性能检验物、校正物、内标物在样品分析过程中的应用。     

Long Period Benzene Measurements in Urban Atmosphere

Periodogram analysis has been used as an interpretative tool of long period measurements of benzene concentration in urban atmosphere. By removing the request of evenly sampled data, the periodogram allows to extend spectral analysis to this kind of data, which usually suffer the "missing data" problem due to instrument vacancies. In this way it is possible to identify the periodic behaviour of data concentration and then reproduce it by means of harmonic functions even for very incomplete experimental information allowing a good evaluation of some important statistical properties of data.