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271.
超高效液相色谱串联质谱法检测鱼体中的全氟化合物   总被引:2,自引:0,他引:2  
采用超高效液相色谱-串联质谱联用法(UPLC-ESI-MS/MS),建立了检测1种贝类和2种鱼类的肌肉组织中11种全氟化合物(PFCs)的分析方法.采用碱液消解做为样品前处理法,选Carbon/NH2双层SPE小柱做为净化小柱,并以ACQUITY UPLC BEH C18为分析柱,甲醇和2 mmol.L-15%甲醇乙酸铵溶液为梯度淋洗液.所选定的11种全氟化合物在6 min内就可以达到良好分离,外标法定量.平均回收率在72.1%—93.6%之间,相对标准偏差在0.6%—9.5%之间,实际检出限在3.4—26.7 pg.g-1.  相似文献   
272.
Acacia longifolia, a highly invasive species that invades coastal ecosystems in Mediterranean areas, produces significant impacts at different scales. Abundant foliage and thick canopies create a dense atmosphere that led us to hypothesise that the release of volatile organic compounds (VOCs) could play a role in the reduction of biodiversity observed in invaded areas. Therefore, we suggested that VOCs emitted by A. longifolia could exert inhibitory effects on physiological and biochemical parameters of native species. Using glass chamber bioassays, we evaluated the effect of aerial contact between VOCs from different plant parts of A. longifolia material and some native species. Volatile chemical composition was further analysed using GC-MS. Our results indicated that VOCs produced a notably reduction of seed germination. Furthermore, volatiles from leaves and flowers significantly decreased root length, shoot length and biomass for all species. Proline and malondialdehyde content did not significantly increase after contact with VOCs. Finally, chemical profile of VOCs from flowers, leaves and litter was significantly different, both qualitatively and quantitatively. As far as we know, our results constitute the first evidence of phytotoxicity induced by VOCs from A. longifolia, suggesting that flowers and leaves could influence its surrounding environment through VOCs release.  相似文献   
273.
In this study, the current situation of five types of toxic organics and endocrine disrupters in the sediments of rivers around Beijing, i.e., polycyclic aromatic hydrocarbons (PAHs), phthalic acid esters (PAEs), organic chlorinated pesticides (OCPs), estrogens (Es), and bisphenol A (BPA), which included 56 contaminants, was analyzed and compared with that registered by the historical literatures. The ecological risks were also assessed. The total concentration of PAHs, PAEs, OCPs, Es, and BPA ranged from 232.5 ng·g–1 to 5429.7 ng·g–1, 2047.2 ng·g–1 to 18051.5 ng·g–1, 4.5 ng·g–1 to 11.7 ng·g–1, 18.1 ng·g–1 to 105.2 ng·g–1, and 36.3 ng·g–1 to 69.6 ng·g–1, respectively. Among these five types of organic compounds, the concentration levels of PAHs and OCPs have decreased significantly in the last ten years, while those of PAEs and Es had an upward trend compared with the previous studies. BPA still remained at a moderately high level, as it was ten years ago. The risks of the PAEs in all of the sample sites, and fluoranthene, benzo[a]anthrene, and benzo[a]pyrene in the Wenyu River sediment, were relatively high. These results supplemented the database of toxic organics’ concentration levels in the sediments of Beijing rivers.
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274.
Treating water contaminants via heterogeneously catalyzed reduction reaction is a subject of growing interest due to its good activity and superior selectivity compared to conventional technology, yielding products that are non-toxic or substantially less toxic. This article reviews the application of catalytic reduction as a progressive approach to treat different types of contaminants in water, which covers hydrodehalogenation for wastewater treatment and hydrogenation of nitrate/nitrite for groundwater remediation. For hydrodehalogenation, an overview of the existing treatment technologies is provided with an assessment of the advantages of catalytic reduction over the conventional methodologies. Catalyst design for feasible catalytic reactions is considered with a critical analysis of the pertinent literature. For hydrogenation, hydrogenation of nitrate/nitrite contaminants in water is mainly focused. Several important nitrate reduction catalysts are discussed relating to their preparation method and catalytic performance. In addition, novel approach of catalytic reduction using in situ synthesized H2 evolved from water splitting reaction is illustrated. Finally, the challenges and perspective for the extensive application of catalytic reduction technology in water treatment are discussed. This review provides key information to our community to apply catalytic reduction approach for water treatment.
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275.
近年来,汽油车尾气排放已成为城市大气污染的主要来源之一.为减少油耗、温室气体和大气污染物的排放,汽油直喷技术(GDI)、醇类燃料替代以及混合动力系统等新兴技术被应用到汽车产品中,该研究对GDI发动机汽车、醇类燃料车和混合动力车的颗粒物(PM)、氮氧化物(NOx)、总碳氢化合物(THC)的排放研究进行梳理和总结,综合评估先进动力技术和醇类燃料的环境影响.结果表明:GDI汽油车的PM排放因子为进气道喷射(PFI)汽油车的1.2~5倍,加装汽油颗粒物捕集器(GPF)后GDI汽油车的PM排放大幅下降,同时具备催化能力的GPF可减少NOx和THC排放.与汽油车相比,乙醇燃料车PM排放量减少了35%~56%,尾气THC排放减少了10%~44%,但挥发性有机物(VOCs)蒸发排放增加了20%~41%,其主要来自于日呼吸损失.各类型车辆的NOx排放差异较小,比较结果存在一定的不确定性.混合动力车相比传统内燃机汽车污染物减排优势明显,可积极推广其在公共交通和私家车队中的应用.建议今后研究应着重关注以下几个方面:①GDI和混合动力车在实际条件下排放污染物的环境影响;②醇类燃料车VOCs蒸发排放控制技术及相关法规标准的完善;③新兴技术汽油车排放污染物的生成机理及其影响因素.   相似文献   
276.
为掌握印刷行业VOCs(挥发性有机化合物)污染特征,进一步科学合理地推进印刷行业VOCs减排,利用“气袋法采样+实验室FID检测”以及便携式非甲烷总烃测试仪对京津冀地区25家典型印刷企业VOCs排放情况进行检测.基于21类含VOCs原辅材料的VOCs含量及时应使用环节废气VOCs浓度的监测结果,得出不同类型原辅材料VOCs含量水平,以及产污环节的VOCs废气浓度水平.结果表明:①油墨VOCs含量范围为0.05%~76.9%,胶印油墨、凹印油墨、柔印油墨和网印油墨符合GB 38507—2020《油墨中可挥发性有机化合物(VOCs)含量的限值》中含量限值的样品数分别占抽检样品总数的98.3%、85.7%、66.7%和100.0%,VOCs含量水平差别较大.②润版液、清洗剂、胶粘剂、光油等原辅材料VOCs含量水平分别为0.4%~45.0%、3.0%~98.7%、0.1%~60.0%、0.1%~50.0%,其中溶剂型样品VOCs含量明显高于水性、UV样品.③从生产过程VOCs产污水平来看,同类工艺的烘干环节VOCs产污浓度普遍高于印刷、清洗、润版等环节;采用溶剂型油墨、胶粘剂、光油的生产工艺VOCs产污浓度(100.0~5 000.0 mg/m3)明显高于其他工艺类型(10.0~500.0 mg/m3);VOCs产污浓度最高的为采用溶剂型油墨的凹版印刷工艺(300.0~5 000.0 mg/m3),其次为采用溶剂型胶粘剂的干式复合工艺(300.0~1 000.0 mg/m3)和采用溶剂型光油的上光工艺(200.0~1 000.0 mg/m3).研究显示,平版胶印、柔印、丝印、复合、上光等工艺均可通过源头替代达到较低的VOCs产污浓度水平(≤50.0 mg/m3),但凹印工艺在采用水性墨替代后VOCs产污浓度水平为50.0~500.0 mg/m3,仍需采取高效的末端处理措施.   相似文献   
277.
为掌握不同涂料类型废气之间的排放差异,基于溶剂型、水性、溶剂型辐射固化(ultra-violet,UV)、水性UV和粉末等不同涂料类型,选取典型家具制造企业进行废气采样,对比研究不同涂料类型废气挥发性有机物(volatile organic compounds,VOCs)排放浓度和组分差异,并对不同涂料类型废气的臭氧生成潜势(ozone formation potential,OFP)和二次有机气溶胶生成潜势(secondary organic aerosol formation potential,SOAFP)进行分析.结果表明,溶剂型涂料废气的总挥发性有机化合物(total volatile organic compound,TVOC)浓度、OFP和SOAFP均高于水性、溶剂型UV、水性UV和粉末涂料废气.不同涂料类型有组织废气VOCs浓度水平和组成差异较大.溶剂型涂料和溶剂型UV涂料废气以芳香烃和含氧挥发性有机物(oxygenated volatile organic compounds,OVOCs)为主,芳香烃的占比分别为41.91%~60.67%和42.51%~43.00%,OVOCs的占比分别为24.75%~41.29%和41.34%~43.21%.水性涂料、水性UV涂料和粉末涂料废气中VOCs占比最高的是OVOCs,占比分别为54.02%~62.10%、55.23%~64.81%和42.98%~46.45%.溶剂型涂料废气的主要组分为苯乙烯(14.68%),水性涂料废气的主要组分为甲缩醛(14.61%),溶剂型UV涂料和水性UV涂料废气的主要组分均为乙酸丁酯(15.36%和20.56%),粉末涂料废气的主要组分是3-乙氧基丙酸乙酯(20.19%).芳香烃对溶剂型涂料和溶剂型UV涂料废气的OFP贡献最大,分别为79.84%和80.32%.水性涂料和水性UV涂料废气OFP的主要贡献者是芳香烃(51.48%和36.71%)和OVOCs(42.30%和41.03%).芳香烃(43.46%)、OVOCs(28.06%)和烯烃(25.24%)是粉末涂料OFP的主要贡献者.芳香烃是溶剂型涂料、水性涂料、溶剂型UV涂料、水性UV涂料和粉末涂料废气SOAFP的绝对贡献者,占比均超过99%.  相似文献   
278.
Abstract:  The utility of a species can be divided into its direct, indirect, and options values. In the marine environment, direct consumptive values predominate and often lead to overexploitation at the expense of significant options values derived through bioprospecting for natural products. We surveyed the waters of the Egyptian Red Sea coast (Gulf of Aqaba [north] and the Red Sea [south]) for species of sea cucumbers and analyzed extracts from species for a range of bioactivities with potential biomedical applications. All habitat types were surveyed within these regions. We found 22 species of sea cucumber of which two, Holothuria fuscogilva and Holothuria flavomaculata , were recorded in Egypt for the first time. Although none of the species identified were unique to the Gulf of Aqaba, 10 species were only found in the Red Sea sector. Bioassay results showed that although no species had antibacterial activity, most extracts exhibited activity against Candida and Leishmania but were most active against a LoVo mammalian carcinoma cell line. Our most significant finding was the intraspecific variation in bioactivity in individuals collected from different habitat types and sectors of the coast. This variation may reflect the effect of environment on secondary metabolite production or may indicate significant genetic diversity between populations within a species. Our results indicate a potentially significant options value to sea cucumbers through bioprospecting. Given the importance of economic development in countries such as Egypt and the perceived low conservation value of invertebrates such as sea cucumbers, the linking of these factors to conservation is vital for the maintenance and sustainable exploitation of these animals .  相似文献   
279.
全氟化合物的生物富集效应研究进展   总被引:5,自引:0,他引:5  
研究污染物的生物富集效应,对于预测污染物在生物体内的含量、建立环境标准以及评估污染物的生态风险具有重要的意义。结合近年来国内外报道的有关全氟化合物(PFCs)的生物浓缩因子(BCF)、生物富集因子(BAF)、生物放大因子(BMF)和营养级放大因子(TMF)等参数,对PFCs的生物富集效应及其影响因素进行了综述。研究结果表明,氟代碳原子数高于7的PFCs一般在生物体或食物链(网)上具有生物富集效应,而氟代碳原子数低于7的PFCs的生物富集效应较低。PFCs的理化性质(碳链长度、碳链末端基团类型和是否含有支链等)、生物的种类及其生理生化参数(体长、体重和性别等)和环境条件(生态系统的组成、水温和污染物含量等)等都影响PFCs在生物体内或食物链(网)上的富集。综观当前研究成果,PFCs在食物链(网)上生物放大效应研究主要集中于极地地区海洋食物网,应加强其他区域(特别是典型污染区域)、各种类型食物网(如淡水食物网和陆生食物网)上PFCs的生物富集效应及其影响因素研究,为全面评估PFCs的生态风险提供基础数据。  相似文献   
280.
Identification and determination of polycyclic aromatic hydrocarbons (PAHs) in Diesel exhaust in the working environment and assessment of workers’ occupational exposure to these suspected human carcinogens were the aim of this experimental investigation.

The range of exposure factors calculated on the basis of 9 individual PAH concentrations determined in personal air samples shows that time-averaged concentration of these compounds did not exceed the Polish Maximum Admissible Concentration (MAC) value for PAHs, that is, 2 μg·m–3. The highest concentrations of PAHs were determined in the breathing zone of forklift operators. The maximum exposure factor was 0.427 μg·m–3 (about 1/4 of MAC).  相似文献   
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