南京地区大气气溶胶及水溶性无机离子特征分析

于2010~2011年在南京市城郊两个采样点收集了气溶胶样品,并利用离子色谱(IC)法分析了其中的水溶性无机离子成分.结果表明,采样期间除了夏季,其他3个季节南京城郊气溶胶污染都较严重.南京城郊气溶胶谱分布特征基本在0.65~2.1μm和5.8~9μm粒径段出现峰值.PM2.5与能见度的相关性很大.城郊离子总质量浓度均是春冬季高于夏秋季,四季阴离子质量浓度明显高于阳离子,且这一特征在细粒子上表现明显.水溶性离子在气溶胶中所占比例是夏秋冬季城区高于郊区.南京城郊NO3-/SO42-年均值表明采样期间燃煤仍然是主要污染源,且该比值夏季最低,冬季最高.NH4+、K+、NO3-和SO42-主要富集在细粒子上;Na+、Cl-和NO2-在粗粒子和细粒子上都有富集;Ca2+、Mg2+和F-主要在粗粒子上富集.因子分析(FA)的方法表明南京城区气溶胶主要有3个来源.     

杭州市大气气溶胶光学厚度研究

利用2011~2012年杭州国家基准气候站内太阳光度计(CE-318)观测资料,分析杭州市气溶胶光学厚度(AOD)和Angstrom波长指数(α)的变化特征.结果表明,2011~2012年杭州市AOD500nm年平均值为0.86?0.47,α440~870nm年平均值为1.25?0.23.AOD季节变化特征不明显,主要与该地区天气形势以及内外源影响密切相关.α季节变化差异也不大,受北方带来的沙尘气溶胶影响,春季α略偏低.AOD呈现单峰型日变化特征,峰值出现在15:00,谷值出现在06:00,午后AOD明显升高主要与强烈的太阳辐射引起光化学反应产生的二次气溶胶以及近地层气溶胶在湍流输送作用下向城市上空扩散有关.从频率分布来看,AOD和α频率分布均呈现明显的单峰特征,并且较好的符合对数正态分布.α在高值区间1.1~1.7出现频率为77.8%,表明杭州市以平均半径较小的气溶胶粒子为主,属于城市-工业型气溶胶类型.杭州市AOD的高值(1.0)主要表现为粗模态气溶胶以及细模态气溶胶的吸湿增长.     

Dry deposition of PM10 over the Yellow Sea during Asian dust events from 2001 to 2007

Dry deposition velocities and fluxes of PM10during Asian dust events over the Yellow Sea from 2001 to 2007 were investigated using observation data in Qingdao, China and Jeju, Korea. The dry deposition velocities of PM10 during dust events over the Yellow Sea ranged from 0.19 to 8.17 cm/sec, with an average of 3.38 cm/sec. Dry deposition fluxes of PM10during dust events over the Yellow Sea were in the range of 68.5–2647.1 mg/(m2·day), with an average of 545.4 mg/(m2·day), which is 2–10 times higher than those reported by other studies for both dust and non-dust periods. It was estimated that 2.6 × 1011–48.7 × 1011g dust particles deposit to the Yellow Sea during dust events through dry deposition every year. Compared with the results in previous studies, it was found that the dry deposition of PM10over the Yellow Sea during dust events in the years with high frequency of dust could account for a large or overwhelming fraction of the annual total dry deposition. Backward air mass trajectory analysis showed that dust events influenced Jeju mainly originated from the desert regions located in Mongolia and Inner Mongolia, China. There were 119 backward trajectories influenced both Qingdao and Jeju during 15 dust events from 2001 to 2007, accounting for 61.3% of the total trajectories of 194, indicating that Qingdao and Jeju were usually on the same pathway of dust transport downwind from source areas.     

Characteristics of secondary inorganic aerosol and sulfate species in size-fractionated aerosol particles in Shanghai

Sulfate, nitrate and ammonium(SNA) are the dominant species in secondary inorganic aerosol, and are considered an important factor in regional haze formation. Size-fractionated aerosol particles for a whole year were collected to study the size distribution of SNA as well as their chemical species in Shanghai. SNA mainly accumulated in fine particles and the highest average ratio of SNA to particulate matter(PM) was observed to be 47% in the fine size fraction(0.49–0.95 μm). Higher sulfur oxidation ratio and nitrogen oxidation ratio values were observed in PM of fine size less than 0.95 μm. Ion balance calculations indicated that more secondary sulfate and nitrate would be generated in PM of fine size(0.49–0.95 μm). Sulfur K-edge X-ray absorption near-edge structure(XANES) spectra of typical samples were analyzed. Results revealed that sulfur mainly existed as sulfate with a proportion(atomic basis) more than 73% in all size of PM and even higher at 90% in fine particles. Sulfate mainly existed as(NH4)2SO4 and gypsum in PM of Shanghai. Compared to non-haze days, a dramatic increase of(NH4)2SO4 content was found in fine particles on haze days only, which suggested the promoting impact of(NH4)2SO4 on haze formation. According to the result of air mass backward trajectory analysis, more(NH4)2SO4 would be generated during the periods of air mass stagnation. Based on XANES, analysis of sulfate species in size-fractionated aerosol particles can be an effective way to evaluate the impact of sulfate aerosols on regional haze formation.     

空调病房真菌气溶胶浓度及粒径分布特征

医院室内空气真菌污染会影响医护人员、病人及陪护人员的健康,其影响程度不仅与空气真菌的种类和浓度有关,还与真菌气溶胶粒径及分布特征有关,不同粒径的真菌气溶胶影响人体健康的作用机制不同.本研究对重庆某综合医院的普通病房进行空气真菌取样,系统分析了病房空气真菌浓度、种属及粒径分布特征.通过分析实验数据,发现病房空气真菌浓度与病人患病类型及人员密度无关,主要影响因素为温湿度与季节变化.冬夏各科室病房真菌粒径分布特征大致呈正态分布,粒径的百分比从Ⅰ级~Ⅲ级各级所占比例逐渐增大,Ⅲ级~Ⅴ级所占比例总体最大,Ⅴ级~Ⅵ级所占比例逐渐降低.冬夏不同科室病房的空气真菌孢子中值直径没有显著差异,真菌孢子的中值直径小于3.19μm.病房冬夏优势菌属基本相同,主要为青霉属、曲霉属及交链孢霉属,与其它建筑相比并无显著性差异.因此,病房空调系统设计应提高对粒径为1.1~4.7μm真菌孢子的过滤效率,病房的日常卫生维护与空调系统运行管理时应有针对性地选择适宜的抑菌除菌方法和设备.     

结合激光雷达分析2014年春季南京地区一次大气污染过程

利用环境监测数据、气象数据以及数值模拟结果,结合激光雷达数据反演的气溶胶消光系数,分析了2014年5月26日至6月1日南京地区一次典型的大气污染过程.本次污染过程受到外源性沙尘和烟尘输入以及本地污染排放叠加影响.气象因素对污染物的生消起到了重要作用,低压、逆温等因素阻碍污染物扩散,最终强降雨的出现使本次污染过程终结.整个污染过程中大气边界层高度偏低且变化不大,大气形势稳定,污染物扩散困难.激光雷达可以有效探测气溶胶的垂直分层结构,能直观准确地反映出污染物的分布聚集情况以及时空变化,对大气污染监测具有重要意义.     

资讯

要闻3月15日,环境保护部党组书记、部长周生贤主持召开环境保护部党组中心组(扩大)学习会,传达学习十一届全国人大五次会议和全国政协十一届五次会议精神,动员部署开展"基层组织建设年"活动。     

气溶胶灭火系统及其误喷事故原因分析

气溶胶灭火系统在运行过程中误喷事故屡屡发生。所谓误喷，即灭火装置在无火灾的情况下非正常启动而喷放灭火剂。出现误喷以后整个系统所属部件提供者都受牵连，常常引起相关厂家、使用单位和管理部门的相互争议、推诿，严重影响着气溶胶灭火技术的健康发展。为此，有必要从烟火技术理论及系统中各部件所起的功能作用加以论述，以求统一认识，找出误喷症结和解决办法，消除误喷事故的发生。     

2006年春季石家庄市沙尘天气与PM_(10)污染

文章应用气象资料和环境监测逐时资料,对2006年春季石家庄市出现的沙尘天气过程中PM10浓度变化,及其与污染源、天气形势、风、周边环境等的关系进行分析。结果表明,沙尘天气的首要污染物均是PM10,PM10的变化曲线呈正态分布,春季中度及以上污染日均出现在污染日当日或次日。造成石家庄沙尘天气污染源分本地型、外来型以及两者共同影响型三种。本地型沙尘污染强度取决于风速大小及强风持续时间,PM10浓度变化与风速呈正相关。而外来型污染多发生在地面弱气压场,PM10浓度变化与风速呈反相关。文章总结出沙尘天气污染预警的几个必要条件,可供实际的空气质量预警参考。     

大气气溶胶物质来源研究进展

大气气溶胶物质来源研究是在气污染研究极为重要的内容，它对污染物质的追踪评价具有较大的意义，本文较为系统地讨论了大气气溶胶物质来源研究的现状，从气溶胶的特征上分别论述气溶胶物质来源的矿物学（颗粒），无机化学和有机化学研究的进展。