硝基芳香烃废水处理技术研究进展

本文综述了硝基芳香烃废水处理技术的研究现状及在实际工程中的应用现状 ,这些技术的原理主要基于物理、化学、生物等方面的作用。同时本文还展望了此类废水处理技术的应用前景 ,采用生物处理及其他多种处理方法协同作用已成为发展趋势。     

Mixed uncertainty analysis of polycyclic aromatic hydrocarbon inhalation and risk assessment in ambient air of Beijing

This article presents the application of an integrated method that estimates the dispersion of polycyclic aromatic hydrocarbons (PAHs) in air, and assesses the human health risk associated with PAHs inhalation. An uncertainty analysis method consisting of three components were applied in this study, where the three components include a bootstrapping method for analyzing the whole process associated uncertainty, an inhalation rate (IR) representation for evaluating the total PAH inhalation risk for human health, and a normally distributed absorption fraction (AF) ranging from 0% to 100% to represent the absorption capability of PAHs in human body. Using this method, an integrated process was employed to assess the health risk of the residents in Beijing, China, from inhaling PAHs in the air. The results indicate that the ambient air PAHs in Beijing is an important contributor to human health impairment, although over 68% of residents seem to be safe from daily PAH carcinogenic inhalation. In general, the accumulated daily inhalation amount is relatively higher for male and children at 10 years old of age than for female and children at 6 years old. In 1997, about 1.73% cancer sufferers in Beijing were more or less related to ambient air PAHs inhalation. At 95% confidence interval, approximately 272–309 individual cancer incidences can be attributed to PAHs pollution in the air. The probability of greater than 500 cancer occurrence is 15.3%. While the inhalation of ambient air PAHs was shown to be an important factor responsible for higher cancer occurrence in Beijing, while the contribution might not be the most significant one.     

多溴联苯醚对芳香烃受体的激活作用及其介导毒性的研究进展

多溴联苯醚(polybrominated diphenyl ethers,PBDEs)是一类全球广泛存在的有机污染物,由于具有环境持久性,远距离传输,生物可累积性及对生物和人体有毒害效应等特性,是当前环境科学的热点研究对象之一.PBDEs的毒性包括生殖毒性、神经毒性、内分泌干扰、DNA损伤、免疫影响等,对人类以及环境具有潜在的威胁.芳香烃受体(aryl hydrocarbon receptor,AhR)是一种配体激活转录因子,诱导许多编码药物代谢酶的基因,可以被二噁英强效激活并引发一系列毒性.PBDEs具有与二噁英相似的结构,而被认为是一种潜在的AhR配体,但是PBDEs通过AhR介导的毒性机理仍然不明确.本文介绍和讨论了近10多年来PBDEs对AhR激活作用的研究,以及诱导的基因表达和毒性效应.虽然各文献的研究手段以及结论不尽相同,大多数研究表明大部分PBDEs对AhR的激活效果较为微弱,但仍有些PBDE需要引起重视.例如,BDE-126在大鼠肝细胞中的激活作用比其同系物更为突出,BDE-99可以激活斑马鱼胚胎中的AhR.此外,大多数羟基化或甲氧基化多溴联苯醚在家禽胚胎肝细胞、大鼠肝癌细胞中可以激活AhR,且可能比PBDEs具有更高的毒性和生物积累性.     

一种生产低硫汽油的预处理方法

日前,美国SK公司成功开发了一种直接生产低硫汽油(ULSD)的新工艺。在这种独特的工艺中,首先对加氢脱 硫(HDS)之前的催化原料采用双吸附塔床脱除其中的含氮化合物,而低氮原料能在不太苛刻的条件(较低温度)下 被加氢处理,产生形成低硫含量的加氢流出液(废水)。     

Emission factors of polycyclic aromatic hydrocarbons from domestic coal combustion in China

Domestic coal stove is widely used in China, especially for countryside during heating period of winter, and polycyclic aromatic hydrocarbons （PAHs） are important in flue gas of the stove. By using dilution tunnel system, samples of both gaseous and particulate phases from domestic coal combustion were collected and 18 PAH species were analyzed by GC-MS. The average emission factors of total 18 PAH species was 171.73 mg/kg, ranging from 140.75 to 229.11 mg/kg for bituminous coals, while was 93.98 mg/kg, ranging from 58.48 to 129.47 mg/kg for anthracite coals. PAHs in gaseous phases occupied 95% of the total of PAHs emission of coal combustion. In particulate phase, 3-ring and 4- ring PAHs were the main components, accounting for 80% of the total particulate PAHs. The total toxicity potency evaluated by benzo[a]pyrene-equivalent carcinogenic power, sum of 7 carcinogenic PAH components and 2,3,7,8-tetrachlorodibenzodioxin had a similar tendency. And as a result, the toxic potential of bituminous coal was higher than that of anthracite coal. Efficient emission control should be conducted to reduce PAH emissions in order to protect ecosystem and human health.     

芳香烃菲与基因碱基的非共价结合及驱动机制

疏水芳香烃类化合物能够导致基因遗传性的变化,理解这些化合物对基因污染的前提是必须首先阐明污染物-基因碱基间相互作用及驱动机制.使用等温吸附-光纤固相萃取和定量-构效关系的方法,研究了模型化合物菲与4种基因碱基间的弱相互作用,并揭示了分子驱动机制.结果表明,p H=7.0条件下,腺嘌呤与菲间引力较弱;而鸟嘌呤、胞嘧啶和胸腺嘧啶对菲为分配吸附,引力较强.红外光谱和弱力等值面的分析表明,鸟嘌呤与腺嘌呤分子能够通过2组CN环(CN6环和5环)与菲的2个相互毗邻的苯核同时发生π-π引力作用;而胞嘧啶和胸腺嘧啶仅与菲弧角位置的碳原子通过电子"赠体-受体"发生静电引力作用.当环境体系变成酸性时,腺嘌呤对菲的吸附增强(分配,1/n=1),但胸腺嘧啶对菲的吸附变弱;碱性条件下,由于胞嘧啶和胸腺嘧啶存在羰基取代基,作为电子赠体的含氧嘧啶脱质子化,表面负电性增强,分子平面极化减弱,π电子更易于与菲弧角位的碳原子发生电子"赠体-受体"作用.能量计算的结果表明,对基因碱基作用位点的预测结果可信,属于自发的非共价成因的物理结合.该研究将为深入揭示芳香烃的基因污染提供理论基础,对于防治芳香烃污染、保障生态安全有重要意义.     

乙醇汽油对国六直喷汽油车排放特性的影响

选择5台国六直喷汽油车采用3种不同组分的E10乙醇汽油和1种不含含氧化合物的国VI汽油，按照国六排放标准开展了WLTC循环测试，研究乙醇和基础油组分对污染物排放的影响规律.结果表明，多数国六直喷汽油车的CO、THC和PM排放有所降低，NO_x排放无明显差异，PN排放微增，所有样车的CO、THC和PM平均排放降低为6%、7%和14%.E10乙醇汽油中的重质芳香烃含量增高时，PN排放明显增加，PN排放与PMI指数呈现较强的正相关关系.     

北京奥运时段VOCs浓度变化、臭氧产生潜势及来源分析研究

挥发性有机物(VOCs)是大气中光化学污染臭氧(O3)的重要前体物,其在大气中的浓度水平往往直接影响着臭氧的污染水平.以2008年夏季北京大气中VOCs浓度观测资料为基础,分析了VOCs浓度和组分随时间的变化特征,比较了各组分对臭氧产生的影响潜势,并利用主成分分析法研究了VOCs主要来源.结果表明,北京大气总VOCs在上午和下午的浓度分别是34.38×10-9(体积分数)和27.13×10-9(体积分数),组分中以烷烃最高,芳烃次之,烯烃最低,下午大气中VOCs浓度显著低于上午,烯烃、芳烃和烷烃依次下降28%、26%和15%;其中1,2,4-三甲苯等效丙烯浓度最高(8.05×10-9C),其次为间对二甲苯(6.97×10-9C)、甲苯(6.41×10-9C)和1,3,5-三甲苯(5.64×10-9C);芳烃对大气O3生成贡献最大(47%),其次是烯烃(40%),烷烃最低(13%).北京大气中VOCs主要来源于机动车(28%)、溶剂挥发(19%)、液化气泄漏(15%)和工业排放(12%).为遏制近年来夏季O污染加重趋势,北京应大力减少VOCs排放,特别是芳香烃的排放量.     

长沙大气中VOCs研究

应用大气采样罐采样技术和色谱-质谱联用（GC-MS）技术,对2008年长沙市大气中76种挥发性有机物（VOCs）的组分及其质量浓度水平进行测试,比较了各组分对臭氧产生的影响潜势,同时对其主要来源进行简单分析.结果表明,长沙大气总VOCs在上午和下午的浓度分别是38.4×10-9（体积分数）和22.7×10-9（体积分数）,下午大气中VOCs浓度显著低于上午;季节变化呈现VOCs冬季浓度远高于夏季VOCs浓度,组分中以卤代烃最高,烷烃、芳烃次之,烯烃最低,OH消耗速率最高的物质是间、对二甲苯（10.71×10-9 C,碳单位体积比,下同）;其次为1,2,4-三甲苯（6.04×10-9 C）和1,3,5-三甲苯（2.23×10-9 C）.芳烃对大气O3生成贡献最大（66%）,其次是烯烃（26%）,烷烃最低（8%）.高浓度的异戊烷和丙烷说明了机动车排放和液化石油气是VOCs来源之一,苯/甲苯的特征比值接近0.8,远高于机动车尾气排放特征比值0.5;说明溶剂和涂料挥发是其主要来源之一.