苏州市沙尘天气下灰霾污染规律研究

结合2010年苏州市出现的一次典型沙尘天气,利用环境空气自动监测数据、气象观测数据及后向轨迹模型等资料,对此次沙尘污染过程进行分析,探究苏州沙尘天气下灰霾污染的规律.结果表明:苏州沙尘天气主要是北方冷空气活动频繁,高空维持较强西北气流造成沙尘颗粒物长程传输造成的;沙尘影响过程中环境空气中可吸入颗粒物浓度明显升高,其他灰霾特征污染物也有所增长,大气能见度降低并伴随城市灰霾现象发生.     

沈阳地区冬季空气颗粒物输送路径及潜在源分析

文章利用2016～2017年冬季沈阳地区气象数据和环境空气污染物浓度数据,综合分析沈阳地区冬季环境空气污染特征,分析颗粒物输送路径以及潜在源区贡献情况.结果表明,沈阳地区冬季污染时段内PM2.5是主要污染物,PM2.5平均浓度达到149μg/m3,最大值达到273 μg/m3.沈阳地区环境空气颗粒物除来源于本地排放外,...     

长春市区冬季空气中颗粒物污染日特征分析

根据长春市环境监测中心站2011－2012年冬季市区各监测点位环境质量监测数据对市区冬季环境空气中颗粒物污染典型日特征进行了分析,分别对交通、水、煤炭对环境空气中的颗粒物影响变化特征进行了比对,浅析了长春市区冬季颗粒物污染的日变化特点,为今后城市环境空气污染防治提供了宝贵的实践经验。     

内江市环境空气颗粒物相关性分析

本文根据内江市城区环境空气自动站2014年10月~2015年9月小时监测数据,研究内江市环境空气中颗粒物(PM10和PM2.5)与其他气态污染物、气象条件的相关性,根据分析结果提出内江市大气污染防治措施。     

可吸入颗粒物与细颗粒物对空气质量等级的影响分析

本文采用青田建设大楼空气自动监测站2013年11月、12月连续24小时自动监测数据,分析了可吸入颗粒物(PM10)与细颗粒物(PM2.5)对空气质量等级评价带来的影响。结果表明,《环境空气质量标准》(GB3095-2012)标准中细颗粒物的引入更能准确地反映出空气质量变化状况,特别是当空气污染时,采用细颗粒物评价更具与人群对空气质量直观感觉的相符性。     

汉中市环境空气颗粒物污染成因分析与防治对策

该文运用汉中市环境保护监测站1985－2000年环境监测数据、汉中市环境保护局2000年环境统计报表、陕西省环境质量报告书和调查，分析了汉中市环境空气中总悬浮颗粒物污染成因，提出了防治与减少污染的对策。     

中外环境空气质量标准比较

颁布实施并于1996年修订且于2000年进行了修改的国家环境空气质量标准(GB3095—1996)已不能适应当前和今后国家环境空气质量管理及评价工作的需求,迫切需要修订. 针对1996年以来国外环境空气质量标准的新进展,研究了美国、欧盟、世界卫生组织(WHO)等国家、地区和组织的环境空气质量标准,就主要污染物控制项目、浓度限值、达标的统计要求及标准实施要求等进行了对比和讨论. 结果表明,PM₁₀,SO₂,NO₂,CO和Pb等仍是绝大多数国家共同控制的污染物,发达国家增加了PM_2.5项目,并有增加苯、重金属等污染物的趋势. 中国未规定污染物达标的统计要求,更没有具体的环境质量标准实施要求,相对放宽了环境空气质量标准,建议未来中国环境空气质量标准修订工作中应综合考虑上述问题.      

天津市环境空气质量现状特征分析研究

利用天津市环境空气监测数据及相关资料,统计分析其环境空气质量状况.结果表明,2013年天津市环境空气质量达标率为40％,重度及以上污染日有49天,主要发生在冬季,超标日的首要污染物以细颗粒物、可吸入颗粒物和臭氧为主.在空气质量污染物构成中,细颗粒物占比为29.43％,其次为可吸入颗粒物占比22.18％,表明天津市大气污染以颗粒物为主.细颗粒物与可吸入颗粒物的月均浓度线性相关系数为0.918 4,占比为64％.除臭氧以外的五项主要污染物在冬季污染最重,夏季污染较轻,臭氧浓度变化与气温变化保持一致,夏季最高,冬季最低.在市域内,滨海新区、蓟县和西青空气质量较好,红桥、宁河和北辰空气质量较差;气态污染物比颗粒物的空间分布更受局地排放的影响,而颗粒物污染分布具有区域性趋势.     

岫岩城区环境空气质量现状及变化趋势分析

通过鞍山市岫岩县城区近五年来环境空气例行监测的数据分析。评价了岫岩城区环境空气质量状况，并通过图示对其变化趋势进行定量描述，同时对该地区环境空气污染特征进行了分析。     

沈阳市采暖期空气可吸入颗粒物重金属组分特征研究

以沈阳市2012—2013年采暖期环境空气中可吸入颗粒物为研究对象,运用微波消解——电感耦合等离子体发射光谱法,测定了PM10中的9种重金属成分,结合相应的环境空气质量自动监测数据,进行了对比分析以及相关性分析,结果表明:城区的PM10浓度低于郊区,但SO2和NO2浓度高于郊区;PM10中,采暖初期Pb,Cr,Ni,As含量远大于中后期;郊区Fe,Mn,Zn,Pb,Hg含量高于市区,工业区Cu高于其他区;Pb,Cr,Ni,As极显著正相关,与Mn极显著正相关,而与Cu,Hg极显著负相关;Zn与Mn,Cu极显著正相关,Cu与Hg极显著正相关。     

双级气浮法处理洗毛废水

阐述了用双级气浮法处理洗毛废水的全部过程及结果.用一种单元操作—双级气浮,加一次药—CK—Ⅱ型洗毛废水处理剂,使排放水的各项指标均达到GB8978—88三级标准,接近二级标准.     

公路施工中空气污染物净化成本对企业财务状况的影响研究

公路建设企业为了不违反施工中空气污染物排放标准,需要追加环保投入,购买先进的空气污染物净化设备,这种情况必然给企业财务状况带来一定的影响。传统的净化技术采用自然通风法来稀释公路施工中的空气污染物,通过空气的流通降低污染物浓度,用于施工段通风的能耗费用和建设费用过大,会给企业造成较大的财务负担。采用ESP技术达到了空气污染物高净化度指标,节省了企业空气污染物净化成本费用。由于企业整个施工项目收益会随着净化成本的降低而增加,所以该技术会对企业财务状况产生一定的影响,污染物净化负债的支付、净化收益费用、支出和产品成本随着净化成本的增加而减少。     

基于WRF-Chem模拟的玉溪市大气环境容量精细估算

云南高原的清洁大气环境及其潜在变化是一个值得深入研究的大气环境问题.本文选择云南高原重要工业城市—玉溪作为研究区域,基于中尺度空气质量模式WRF-Chem,开展玉溪市的大气环境容量模拟估算.同时,以2015年冬、春、夏、秋季主要大气污染物模拟为基础,采用以我国环境空气质量标准(GB3095—2012)为约束目标的WRF-Chem模拟迭代大气环境容量算法,设置3 km的精细分辨率,计算得到2015年玉溪市一次PM_(10)、一次PM_(2.5)、SO_2、NO_x和CO的大气环境容量分别为1.284×10~4、0.854×10~4、1.917×10~4、1.796×10~4和51.556×10~4t·a~(-1).最后,研究了整个玉溪市区域和城区大气环境容量的季节变化特征,结果发现,各污染物冬季大气环境容量最小,除PM_(2.5)外的污染物均在春季大气环境容量最大.玉溪市城区剩余容量占全市的比例均在40%左右,反映了工业发展和城市化带来的大气环境的城乡差异及可能的环境变化效应.     

文山城空气质量监测点位优化研究

用网格实测法对文山城空气质量监测点位进行优化研究,全城共均匀布设12个网格点,2002年4月,连续20d监测了各点大气中SO2、NO2和TSP的浓度,运用模糊聚类法对监测数据进行分析,并综合城市规划、人口分布、污染特征等因素,优选出足以反映文山城空气质量状况的3个最佳监测点.经检验,优选点位的代表性较好,结果满意.     

纳米TiO_2/聚糠醛复合材料NTP的制备及其光催化活性

以糠醛和纳米TiO2为前驱物制备了TiO2/共轭高分子复合材料NTP,并通过TEM、XRD和UV-Vis等技术对其进行了表征。结果表明,NTP为具有活性基团和不同长度共轭链的高分子,其中聚糠醛与TiO2以Ti-O-C相键合;该复合材料对光的吸收拓宽至整个紫外-可见光区。在自然光照射及空气氧存在的温和条件下,前驱物(mg(TiO2):ml(Furfural)=1:80)经350℃热处理30 mins制得的TiO2/P复合材料于1 min内可将所给定染料废水彻底降解褪色。     

Whole-body 3D kinematics of bird take-off: key role of the legs to propel the trunk

Previous studies showed that birds primarily use their hindlimbs to propel themselves into the air in order to take-off. Yet, it remains unclear how the different parts of their musculoskeletal system move to produce the necessary acceleration. To quantify the relative motions of the bones during the terrestrial phase of take-off, we used biplanar fluoroscopy in two species of birds, diamond dove (Geopelia cuneata) and zebra finch (Taeniopygia guttata). We obtained a detailed 3D kinematics analysis of the head, the trunk and the three long bones of the left leg. We found that the entire body assisted the production of the needed forces to take-off, during two distinct but complementary phases. The first one, a relatively slow preparatory phase, started with a movement of the head and an alignment of the different groups of bones with the future take-off direction. It was associated with a pitch down of the trunk and a flexion of the ankle, of the hip and, to a lesser extent, of the knee. This crouching movement could contribute to the loading of the leg muscles and store elastic energy that could be released in the propulsive phase of take-off, during the extension of the leg joints. Combined with the fact that the head, together with the trunk, produced a forward momentum, the entire body assisted the production of the needed forces to take-off. The second phase was faster with mostly horizontal forward and vertical upward translation motions, synchronous to an extension of the entire lower articulated musculoskeletal system. It led to the propulsion of the bird in the air with a fundamental role of the hip and ankle joints to move the trunk upward and forward. Take-off kinematics were similar in both studied species, with a more pronounced crouching movement in diamond dove, which can be related to a large body mass compared to zebra finch.     

Aerosol characterization in a city in central China plain and implications for emission control

Extensive studies on aerosol chemistry have been carried out in megacities in China, however, aerosol characterization in Central China Plain (CCP) is limited. Here we conducted real-time measurements of fine particle composition with a time-of-flight aerosol chemical speciation monitor in Kaifeng, Henan province in October 2019. Our results showed that nitrate and organics constituted the major fraction of non-refractory PM_2.5 for the entire study, on average accounting for 34% and 33%, respectively. However, aerosol composition was substantially different among four periods due to different meteorological conditions and chemical processing. For instance, nitrate presented the lowest contribution during the first period due to evaporative loss associated with high temperature (T), and then rapidly increased during polluted periods as a function of relative humidity (RH). Positive matrix factorization analysis showed the dominance of secondary organic aerosol (SOA) in OA, and also the changes in OA composition under different T and RH levels. In addition, this study is unique with two periods of local emission controls. Back trajectory and coefficient of divergence analysis showed that air pollution in CCP was overall homogeneously distributed. As a result, the effectiveness of local emission controls in this region was strongly affected by meteorological conditions and regional transport. We found that one of the periods with emission control even showed the highest concentrations for the entire study. Our results point towards the limited effect of local emission controls in mitigating air pollution in CCP, and highlight the importance of joint emission controls under unfavorable meteorological conditions.     

2013—2018年北京市大气PM2.5持续高暴露对居民因病入院的急性影响

为探讨以细颗粒物（PM_2.5）持续高浓度暴露为特征的大气污染事件对于人群因病入院的急性影响,收集2013—2018年北京市大气PM_2.5浓度、气象因素数据和人群因病入院数据,以PM_2.5浓度〔75.0 μg/m3、150.0 μg/m3、第95百分位数（205.8 μg/m3）〕和持续时间（≥2 d、≥3 d）联合定义6种持续高暴露情景,采用基于quasi-Poisson回归的广义相加模型开展时间序列分析,获得不同情景下PM_2.5对人群因病入院的急性影响.结果表明:①对于全人群研究发现,相较于非持续高暴露情景,持续2 d及以上的重污染（PM_2.5浓度>150.0 μg/m3）情景引起非意外总疾病和心脑血管系统疾病的发病风险均显著增加,增幅分别为5.0%（95% CI,1.2%~9.0%）和5.6%（95% CI,1.8%~9.5%）.②亚组人群分层分析发现,持续2 d及以上的重污染情景下,男性、女性、0~64岁、65~74岁、75岁及以上等亚组人群的非意外总疾病和心脑血管系统疾病的发病风险均显著增加;当出现极端PM_2.5暴露浓度（>205.8 μg/m3）且持续3 d以及上时,女性和0~64岁、65~74岁人群的非意外总疾病和心脑血管系统疾病的发病风险均显著增加.③因呼吸系统疾病入院分析发现,仅在PM_2.5浓度>150 μg/m3且持续时间≥2 d的情景下,观察到0~64岁人群的发病风险显著增加,增幅为3.4%（95% CI,0.2%~6.6%）.研究显示,以PM_2.5持续高暴露为特征的大气污染事件对人群因病入院有显著影响.      

后奥运时期京津冀区域大气本底夏季污染变化

为探索后奥运时期京津冀区域大气本底污染状况及变化趋势,在中国科学院华北兴隆大气本底观测站,对夏季大气主要污染物(NO_x、SO₂、O₃和PM_2.5)进行了连续3年的在线观测,结合气流轨迹模式对大气污染物的传输路径及贡献率进行了分析. 结果表明:兴隆站大气本底夏季ρ(NO_x)、 ρ(SO₂)、 ρ(O₃)和ρ(PM_2.5)的平均值分别为(11.5±5.9)、(8.3±7.0)、(137.6±38.4)和(50.9±33.0)μg/m3;首要污染物为O₃和PM_2.5,ρ(O₃)和ρ(PM_2.5)日均值超过GB 3095─2012《环境空气质量标准》二级标准〔ρ(O₃)为200 μg/m3,ρ(PM_2.5)为75 μg/m3〕的天数分别为102和60 d,占观测期间有效天数的39%和23%,表现为大气氧化性增强、二次污染逐年上升;受偏南气流影响,太行山沿线区域和山东半岛—渤海湾地区是兴隆夏季大气本底污染的主要贡献区域,特别是京津冀城市区域夏季高浓度O₃和PM_2.5,对华北区域大气本底污染物浓度的整体上升具有重要影响.      

In-vehicle VOCs composition of unconditioned, newly produced cars

The in-vehicle volatile organic compounds （VOCs） concentrations gains the attention of both car producers and users. In the present study, an attempt was made to determine if analysis of air samples collected from an unconditioned car cabin can be used as a quality control measure. The VOCs composition of in-vehicle air was analyzed by means of active sampling on Carbograph 1TD and Tenax TA sorbents, followed by thermal desorption and simultaneous analysis on flame ionization and mass detector （TD-GC/FID-MS）. Nine newly produced cars of the same brand and model were chosen for this study. Within these, four of the vehicles were equipped with identical interior materials and five others differed in terms of upholstery and the presence of a sunroof; one car was convertible. The sampling event took place outside of the car assembly plant and the cars tested left the assembly line no later than 24 hr before the sampling took place. More than 250 compounds were present in the samples collected; the identification of more than 160 was confirmed by comparative mass spectra analysis and 80 were confirmed by both comparison with single/multiple compounds standards and mass spectra analysis. In general, aliphatic hydrocarbons represented more than 60% of the total VOCs （TVOC） determined. Depending on the vehicle, the concentration of aromatic hydrocarbons varied from 12% to 27% of total VOCs. The very short period between car production and sampling of the in-vehicle air permits the assumption that the entire TVOC originates from off-gassing of interior materials. The results of this study expand the knowledge of in-vehicle pollution by presenting information about car cabin air quality immediately after car production.