城市中心街道交通隧道废气排放模拟

利用风洞试验、模式预测和现场监测的方法,对某城市中心街道交通隧道汽车废气的扩散特征作了模拟研究。结果表明,环境中汽车尾气污染程度与隧道中汽车行驶工况、车流量、气象条件（温度、风速、风向）等诸多因素有关。随着环境风速减小或环境气温升高,隧道外废气浓度显著增加。隧道出口至离出口90m处的引道范围是污染物高浓度区域,但废气排放对引道两侧离地面较高的匝道影响较小。对模式预测结果和风洞测量结果、现场监测结果作了比较,一致性良好     

The traffic emission and its impact on air quality in Guangzhou area

A comprehensive field measurement was set up in Guangzhou City of China and the key was placed on NOx and O3 pollution. The results indicated that the average driving speed of vehicle was only 14 km/h in downtown with high frequency of idle and acceleration. Upward fluxes of CO and NO were observed in Dongfeng street. NOx annual mean concentration in urban area increased year by year, and NOx was identified as the most important pollutant since 1995. Photochemical smog pollution was serious in general,spatial and seasonal distribution of O3 was observed. O3 concentration was kept in a high level in autumn, and its formation was restrained in summer due to frequent thunderstorm and high humidity. The numerical simulation showed the average concentration     

Effects of traffic pollution on the genetic structure of Poa annua L. populations

The genetic composition of Poa annua L, populations with a series of traffic pollution was studied by starch electrophoresis. Five enzyme systems were stained. The results showed that: (1) Traffic pollution can dramatically change genotypic frequencies at some loci of P. annua populations. Significant deviations from HardyWeinberg equilibrium were observed on loci Fe - 1 and Me due to the excess of heterozygotes in some populations.(2) The effective number of alleles per locus and the observed and expected heterozygosity were higher in the pollution series than in the clear control site(Botanic Park population), but the increase was not related with the pollution extent. (3) Most genetic variation was found within populations, and only 6.21% was among populations of the polluted series. Slightly higher differentiation( FST = 7.98%) was observed when the control population was included. (4) The calculated gene flow(Nm) is 2.8841 per generation. The mean of genetic identity is 0.9864 and the genetic distance average to 0.0138.     

城区大气颗粒物中有机氯农药的含量与分布

采用FA-3型气溶胶粒度分布采样器采样,对北京和天津2个样点夏季大气中不同粒径颗粒物上有机氯农药残留量进行分析.在所有分级样品中均检测出δ-HCH,p,p'-DDD和p,p'-DDT,其他有机氯农药只在部分样品中被检出.北京样中HCHs(α-HCH+β-HCH+γ-HCH+δ-HCH)含量为0.240ng/m3,DDTs(p,p'-DDT+p,p'-DDD+p,p'-DDE)含量为0.962ng/m3,天津样品中HCHs含量为0.581 ng/m3,DDTs含量为1.874ng/m3.天津样中有机氯农药残留明显高于北京样.大气颗粒物上的有机氯农药粒径分布特征为:北京样中HCHs和DDTs含量随粒径均呈单峰分布,而天津样中HCHs呈三峰态分布,DDTs呈较弱的单峰态分布.HCHs和DDTs两类化合物的质量中值直径和分散度分别在2.1～2.5μm和3.1～3.7μm范围内.      

2018~2020年北京市交通监测站点大气污染特征分析

基于北京市34个空气质量监测站点收集的5种主要污染物浓度（NO₂、CO、O₃、PM_2.5、PM₁₀）数据,对2018~2020年北京市5个交通站点污染物浓度进行分析,并与11个城市评价站点及2个背景点（密云水库、定陵）进行对比.结果表明：（1）3a间各污染物浓度年际变化总体呈下降趋势,除PM₁₀外,交通站点各污染物浓度降幅均大于城市评价站点.2020年交通站点NO₂降幅最大,比2018年下降了31.37%.除个别时期外,5种污染物浓度在交通站点比城市评价站点普遍高出3%~50%.且以NO₂最为突出.（2）2018~2020年各监测站点不同污染物浓度的季节变化特征表现不同.O₃夏季高、冬季低,最高值出现在2018年6月;其余4种污染物浓度基本表现为冬季高、夏季低;2018年3月受沙尘及不利气象条件影响,污染物浓度出现了极高值.（3）为研究新冠肺炎疫情对交通污染排放的影响,比较了5种污染物的浓度变化.与2019年同期相比,疫情后三个阶段的NO₂下降最为显著.交通站点NO₂、CO、PM_2.5平均降幅比城市评价站点高出了4.81%、10.21%、4.38%.     

成都市大气细颗粒物组成和污染特征分析(2012-2013年)

为了解成都市大气细颗粒物的污染特征,于2012年5月-2013年5月在成都市城区开展了每6 d采集1次样品的长期颗粒物观测.利用十万分之一分析天平、热光碳分析仪、离子色谱、电感耦合等离子体质谱(ICP-MS)分别分析了颗粒物样品的质量浓度、有机碳/元素碳、水溶性离子、无机元素等,同步收集了污染物在线观测数据、气象数据和卫星遥感数据.结果表明,采样期间,成都市可吸入颗粒物(PM₁₀)和细粒子(PM_2.5)浓度颗粒物浓度分别高达(129.7±76.4)和(91.6±54.3) μg·m^-3,PM_2.5中以二次无机离子(SNA,43.6%)和有机物(OM,31.2%)污染最为突出,其次为土壤组分(Soil,13.8%)、元素碳(EC,5.0%)和微量元素(Trace,0.8%);1月、3月、5月和10月是污染较重的月份.通过比较揭示了不同污染源影响下的典型污染特征.生物质燃烧期间,成都城区PM_2.5浓度达214.3 μg·m^-3,PM_2.5/PM₁₀比达0.89,其中OM贡献增加至57.2%,K⁺浓度达8.7 μg·m^-3,OC/EC比达8.3,SNA比重下降;而沙尘传输期间,PM_2.5浓度为122.6 μg·m^-3,仅占PM₁₀浓度的0.28,PM_2.5中土壤组分比例剧增至77.3%,SNA和无机元素的比重明显下降;静稳天气下PM_2.5浓度为261.0 μg·m^-3,各组分比重并无明显变化,硝酸盐和铵盐比例稍有增加.     

公路隧道空气中多环芳烃的污染现状及影响因素分析

用XAD－2吸附树脂和玻璃纤维滤膜（GF）同时采集隧道空气中气态和颗粒态的多环芳烃（PAHs）,超声提取样品中的PAHs,采用梯度淋洗和程序化可变波长荧光检测器相结合的高效液相色谱法测定9种只有代表性的多环芳烃,分析并讨论了隧道空气中多环芳烃的浓度、存在形态及其影响因结果表明,九凰山公路隧道空气中PAHs污染非常严重,9种PAHs的总量平均达78．8μg/m³,所测PAHs的种类及浓度与过往车辆所用燃料有关,其存在形态与环境温度有关,人体暴露PAHs的量与其在空气中的浓度成正比     

Effect of traffic restriction on atmospheric particle concentrations and their size distributions in urban Lanzhou, Northwestern China

During the 2012 Lanzhou International Marathon, the local government made a significant effort to improve traffic conditions and air quality by implementing traffic restriction measures. To evaluate the direct effect of these measures on urban air quality, especially particle concentrations and their size distributions, atmospheric particle size distributions(0.5–20 μm) obtained using an aerodynamic particle sizer(model 3321, TSI, USA) in June 2012 were analyzed. It was found that the particle number, surface area and volume concentrations for size range 0.5–10 μm were(15.0±2.1) cm-3,(11.8±2.6) μm2/cm3and(1.9±0.6) μm2/cm3, respectively, on the traffic-restricted day(Sunday), which is 63.2%, 53.0% and 47.2% lower than those on a normal Sunday. For number and surface area concentrations, the most affected size range was 0.5–0.7 and 0.5–0.8 μm, respectively, while for volume concentration, the most affected size ranges were 0.5–0.8, 1.7–2.0 and 5.0–5.4 μm. Number and volume concentrations of particles in size range 0.5–1.0 μm correlated well with the number of non-CNG(Compressed Natural Gas) powered vehicles, while their correlation with the number of CNG-powered vehicles was very low, suggesting that reasonable urban traffic controls along with vehicle technology improvements could play an important role in improving urban air quality.     

兰州市交通要道颗粒物污染状况及其致突变活性的研究

采用现场监测，色－质联用分析以及小鼠骨髓微核试验方法，评价了兰州市交通要道颗粒物的污染状况，分析了颗粒提取物（PE）的有机组成及致突变活性。结果表明，兰州市总悬浮颗粒物（TSP）污染严重。颗粒提取物中含有近100种有机化合物，其中包括致癌性多环芳烃。微核试验显示PE具有致突变活性，对人群健康的影响不容忽视。     

Traffic emission and its impact on air quality in Guangzhou area

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杭州高架道路交通噪声污染现状与防治对策

对杭州上塘-中河高架道路临路第一排敏感点交通噪声监测结果表明,两侧敏感点噪声超标严重。在21个监测点中,昼间超标为8个,最大超标3.9dB,夜间21个点全部超标,最大超标16.2dB。根据噪声污染程度分级,上塘-中河高架道路交通噪声污染属中度污染水平。建设低噪声路面,设置隔声屏障,对敏感点采取安装通风隔声窗等措施,是缓解高架道路交通噪声污染的有效措施。     

Seasonal features of aerosol particles recorded in snow from Mt. Qomolangma （Everest） and their environmental implications

To assess the seasonality of aerosol deposition and anthropogenic effects on central Himalayas, a 1.85-m deep snow pit was dug on the northern slope of Mr. Qomolangma (Everest). Based on the morphology and energy dispersive X-ray (EDX) signal, totally 1500 particles were classed into 7 groups: soot; aluminosilicates; fly ash; calcium sulfates; Ca/Mg carbonates; metal oxides; and biological particles and carbon fragments. The size distribution and number fractions of different particle groups exhibited distinct seasonal variations between non-monsoon and monsoon periods, which are clearly related to the differences in air mass pathways. Specifically, the relative abundance of soot in non-monsoon period (25%) was much higher than that in monsoon period (14%), indicating Mr. Qomolangma region received more anthropogenic influence in non-monsoon than monsoon period.     

长春市典型高架公路大气环境颗粒物中重金属污染特征

于2014年4—11月对长春市典型高架公路大气颗粒物PM_(2.5)和PM_(10)进行采样,对颗粒物中主要重金属元素的浓度进行了分析,并采用变异系数法、地积累指数法和富集因子法对大气颗粒物重金属污染情况进行评价.研究表明,道路施工期间,PM_(2.5)和PM_(10)中重金属的浓度普遍低于道路运行通车后的浓度,而采暖期重金属的浓度又高于非采暖期的浓度.重金属元素在PM_(2.5)中的含量占PM_(10)中总含量的比例均超过50%,说明颗粒物越细越容易富集重金属.Zn、Fe和Mn的变异系数较小,说明来源稳定,自然源占主导地位.富集因子法表明,Zn的富集程度极强,Mn无富集.Cr和Cd的变异系数较大,受人为活动干扰严重,在道路施工期间二者富集程度较轻,道路通行加之采暖后富集程度加强,主要来源为汽油和煤的燃烧.Pb、Cu和Ni的变异系数在0.56~0.76之间,有一定的人为干扰,Pb和Ni在高架公路施工期富集程度较轻,道路运行及取暖期富集程度显著,主要来源是交通源;Cu富集程度强,主要来源可能是油燃烧、建筑扬尘.     

苏州地区水稻土重金属污染源解析及端元影响量化研究

利用国家土壤质量标准和当地背景值评价了苏州地区表层水稻土重金属(Pb、Cd、As、Hg、Cu、Zn、Ni、Cr)的污染(富集)状况.结果发现,苏州地区土壤Cd、Hg、As、Pb、Zn、Cu、Cr和Ni平均含量分别是0.23、0.23、9.14、35.36、103.36、35.75、77.12和33.18μg·g-1;除As外,其余7种重金属平均含量皆明显高于当地土壤背景值.通过与中国土壤环境质量标准(GB15618—1995)相比,发现苏州地区土壤中Cd和Hg是8种重金属中风险最高的.地质累积指数分析表明,苏州水稻土重金属Cd、Hg、Pb、Cu和Zn出现了污染,其中以Cd和Hg的污染程度最突出,约80%的土壤样品出现了Pb轻度污染.因子得分-多元回归法(PCS-MLR)估算表明,70%的土壤Cd来自与有色金属或磷有关的人为活动;土壤中约50%的Pb和72%的Hg源于大气沉降的贡献;土壤的Zn和Cu污染主要来自与有色金属或磷有关的人为活动,该端元对土壤Zn和Cu的影响率分别为53%和45%.     

Characterization of the airborne bacteria community at different distances from the rotating brushes in a wastewater treatment plant by 16S rRNA gene clone libraries

Biological risks of bioaerosols emitted from wastewater treatment processes have attracted wide attention in the recent years. However, the culture-based analysis method has been mostly adopted for detecting the bacterial community in bioaerosols, which may result in the underestimation of total microorganism concentration as not all microorganisms are cultivable. In this study, oligonucleotide fingerprinting of 16S rRNA genes was applied to reveal the composition and structure of the bacterial community in bioaerosols from an Orbal oxidation ditch in a Beijing wastewater treatment plant (WWTP). Bioaerosols were collected at different distances from the aerosol source, rotating brushes, and the sampling height was 1.5 m which is the common respiratory height of a human being. The bacterial communities of bioaerosols were diverse, and the lowest bacterial diversity was found at the sampling site just after the rotating brush rotating brush. A large proportion of bacteria in bioaerosols were affiliated with Proteobacteria and Bacteroidetes. Numerous bacteria present in the bioaerosols also emerged in water, indicating that the bacterial community in the bioaerosols was related to that of the aerosols’ sources. The forced aeration of rotating brushes brought about observably distinct bacterial communities between sampling sites situated before and after the rotating brush. Isolation sources of closest relatives in bioaerosols clone libraries were associated with the aqueous environment in the WWTP. Common potential pathogens in bioaerosols as well as those not reported in previous research were also analyzed in this study. Measures should be adopted to reduce the emission of bioaerosols and prevent their exposure to workers.     

BaP和Cd单一复合对BaP蚯蚓亚细胞分配的影响

选用钙离子通道阻断剂氯化镧（LaCl₃）和巯基蛋白阻断剂N-乙马来酰亚胺（NEM）对赤子爱胜蚓进行预暴露,然后构建BaP单一或Cd-BaP复合污染,研究不同阻断剂对BaP在蚯蚓不同亚细胞组分（Fraction C：细胞溶质组分;Fraction D：固体颗粒组分;Fraction E：细胞碎片组分）中分配积累特征的影响.结果表明,无论单一或复合污染,BaP主要分布于细胞碎片组分中（占55.42%~69.96%）,其次为固体颗粒组分（占27.91%~32.90%）,在细胞溶质组分中的浓度最低（占2.13%~11.67%）.单一BaP污染下,两种阻断剂对BaP的作用相近,即LaCl₃和NEM的加入均能不同程度地促进3个亚细胞组分中BaP的积累.而在Cd和BaP复合污染下,两种阻断剂对BaP的分布积累的影响略有不同,LaCl₃能够促进复合污染下BaP在3个亚细胞组分中的积累,而NEM促进了复合污染下BaP在固体颗粒组分和细胞碎片组分中的积累,但抑制了BaP在细胞溶质组分中的积累,浓度从原来的0.99mg/kg降低至0.59mg/kg.因此,钙离子通道和巯基蛋白可能参与BaP在蚯蚓亚细胞的分配积累,相比单一污染,Cd的复合污会进一步改变BaP的积累分配特征.     

PAHs pollution from traffic sources in air of Hangzhou, China: Trend and influencing factors

Introduction China is experiencing rapid economic and populationgrowth. The rapid growth and increasing fossil fuel energyconsumption have resulted in large amounts of pollutants suchas TSP, SO2, NOx and hydrocarbons to be emitted intoambient atmosphere. Nowadays, national routine monitor haspaid much attention to TSP, SO2 and NOx. Highconcentrations of SO2 and NOx can lead to an increase ofregional levels of acid deposition and tropospheric ozon, thu…     

气浮过程中的界面相互作用

首先讨论了水体颗粒物的基本性质以及气泡的形成过程，而后对气液界面上胶体颗粒的吸附进行分析。其次讨论了气浮过程中，气泡与颗粒物之间的相互作用。对气泡与颗粒物之间的碰撞进行分析。结合紊流气浮的理论与应用，在气浮过程中的界面相互作用分析的基础上。设计了一种新型集成的溶气气浮水处理工艺，即逆流共聚气浮工艺，并对其运行情况进行了研究。探讨了其中的界面相互作用对气浮效果的影响，进一步与传统工艺进行了对比。     

电厂燃煤飞灰中重金属富集规律的实验研究

研究了电厂燃煤排放的４级粒径不同的飞灰中铜、钴、铅、镍、铬、镉、砷、铍的含量及其分布。发现大多数金属在粒径１μｍ左右的细微粒子中有富集特性,其变化趋势与不同飞灰的孔隙特性变化一致,即随飞灰粒径的减小,飞灰的比表面积和孔体积增大,飞灰中金属的浓度也增多。同时比较了２种工况下金属在飞灰中的不同分布,分析了影响飞灰富集特性的各种因素,如飞灰的孔隙特性、燃烧工况、化学吸附作用、矿物质的汽化－凝结作用等,并     

芜湖市交通区表层土壤多环芳烃与黑碳研究

采集芜湖市交通区和对照绿地共40个表层土壤（0~5cm）样品.应用气相色谱-质谱联用仪（GC-MS）测定样品中26种多环芳烃（PAHs）及甲基多环芳烃的浓度,应用化学热氧化法（CTO-375,BC_CTO）、湿化学氧化法（K₂Cr₂O₇/H₂SO₄,BC_Cr）分别测定样品中黑碳（BC）的含量,分析交通区表层土壤PAHs、BC的分布特征、影响区域、相互关系,并利用石油污染指标、多特征比值、正定矩阵因子分解法（PMF）对表层土壤样品中的PAHs进行来源解析.结果表明：表层土壤中PAHs、BC_Cr、BC_CTO的含量均值分别为3.63μg/g,10.23g/kg,2.93g/kg,浓度范围分别为0.075~28.76μg/g,3.78~27.13g/kg,1.07~10.36g/kg.土壤中PAHs、BC的浓度受距路远近影响,距路越近,浓度越高;且呈现出重要交通节点、路口 > 干路、支路 > 绿地的趋势,干支路无显著差异;车流量不是影响交通区土壤PAHs、BC浓度的决定因素,车辆的运行状态是其主导因素.土壤中PAHs以中高环为主.表层土壤中PAHs与两类BC都具有较好的相关性,对照绿地相关性不显著,表明BC对PAHs在土壤中的累积有重要影响,但受其他因素干扰.源解析表明表层土壤样品中PAHs主要来源于交通源.