铝电解工业PM2.5超细粉尘的控制技术研究

分析了铝电解工业PM2.5的来源,估计电解铝生产产生的PM2.5大约为66万t/a,加上铝电解工业其他工段产生的粉尘,整个铝冶炼行业产生的PM2.5粉尘达到80万～100万t/a以上。进行铝电解工业废气排放PM2.5控制技术的研究,实际上是对布袋除尘器过滤技术的研究,包括除尘器内部流场控制技术、用于电解铝行业袋式除尘器专用滤料技术、滤袋上滤饼及清灰控制和烟气平衡自适应控制技术的研究。阐述了有关研究方法及阶段性研究成果,以及下一步的研究目标。     

Characterisation of airborne particles collected within and proximal to an opencast coalmine: South Wales,U.K

Airborne particulate matter has been collected from within,and proximal to, an opencast coal mine in south Wales. Thiswork forms the first part of a three year project to collectand characterise, then determine the possible toxicology ofairborne particles in the south Wales region. High-resolutionField Emission SEM has shown that the coal mine dusts consistlargely of an assemblage of mineral grains and vehicle exhaustparticles. SEM-EDX has shown that the mineralogical make-up ofthe PM10 is complex, heterogeneous, and constantly changing.These findings are supported by analytical TEM-EPXMA.However, patterns can be determined relating the mineralogicalcomposition of the airborne particles to collection locationsand mining activities within the opencast. At our studyopencast, Park Slip West, quartz, which has known healtheffects, never exceeded 30% of the total collection mass, andaverage levels were much less. Vehicle exhaust emissions wasthe largest source in terms of particle numbers. The mass ofairborne particulate matter within the pit averagedapproximately twice that of outside the pit: importantlyhowever, this higher mass was due to relatively large, andnon-respirable, mineral grains. This study demonstrates that the physicochemical andmineralogical characterisation of airborne particles frommining and quarrying is essential to quantify the respirablefraction, and to identify potentially hazardous componentswithin the PM10.     

涡流技术的试验研究与工程应用

本文介绍了一种新型涡流烟气净化装置,并通过模拟试验及工程应用研究了涡流装置、中心力场等有关参数及除尘脱硫的技术经济综合指标。     

Impact of the composition of combustion generated fine particles on epithelial cell toxicity: influences of metals on metabolism

Inhaled airborne particulate matter (PM) represents a potentially significant health hazard to humans. Exposure to PM strongly correlates with pulmonary inflammation and incidences of severe respiratory distress, including increased hospital admissions for breathing disorders, asthma, emphysema, and chronic bronchitis. PM generated from the combustion of fuel oils and coals contain a number of water-soluble transition metals including Fe, V, and Zn.

We have evaluated the impact of PM types with varying composition collected from the combustion of oils and coals on the health and metabolism of lung cell cultures. Three colorimetric assays (sulforhodamine B (SRB), Janus green, and MTT) have been adapted to quantify the impact of PM on rat lung alveolar type II epithelial cells (RLE-6TN cells). The PM toxicity metrics evaluated were inhibition of cell proliferation (SRB and Janus green) and inhibition of cellular metabolism (MTT). Cell proliferation is inhibited in a consistent dose-dependent manner by PM concentrations from 25 to 250 μg/ml. At a level of 100 μg/ml, oil-derived PM diminishes cell metabolism by as much as 40% relative to controls; the degree of inhibition is strongly dependent on PM particle size and metal content. Conversely, coal-derived PM at the same dosage diminishes cell metabolism by no more than 20% relative to controls. All three assays provide highly repeatable results and consistent toxicity rankings of the PMs evaluated. Overall, metabolic inhibition as measured by the MTT assay was deemed the most appropriate metric for PM toxicity, primarily due to its applicability with in vivo-like confluent cell monolayers.     

袋式除尘器滤袋接缝方法对PM_(2.5)过滤效率的影响

针对袋式除尘器超低排放及对PM_(2.5)细颗粒物的捕集控制问题,选用分别经缝合、热熔两种制袋工艺制作的滤袋进行试验,探讨不同袋身接缝方法对袋式除尘器滤袋PM_(2.5)过滤效率的影响。结果表明:1 m/min过滤风速时,清洁状态下热熔滤袋对PM_(2.5)的过滤效率要比缝合滤袋高12.59%,而集尘状态下随滤袋表面粉尘负荷的不同,热熔滤袋对PM_(2.5)的过滤效率要比缝合滤袋高8.68%~11.18%;随过滤风速增加,缝合滤袋对PM_(2.5)过滤效率的衰减幅度要远大于热熔滤袋;滤袋表面尘饼的形成和分布的均匀性是缩小缝合滤袋与热熔滤袋间过滤效率差距的重要因素。     

强电场介质装置对实际环境PM2.5的净化效果

针对室内环境PM_(2.5)污染问题,设计了一台空气净化器,以强电场介质(Intense Field Dielectric,IFD)装置作为其核心过滤元件。在上海某办公室,以香烟烟雾为PM_(2.5)发生源,测试了净化器的一次过滤效率、风量、能耗、臭氧发生量,以及不同档位运行工况下室内PM_(2.5)质量浓度衰减情况和换气次数,并计算了各档位的洁净空气量(Clean Air Delivery Rate,CADR)和净化效能。结果表明,IFD装置能够有效净化实际环境中的高浓度PM_(2.5),其臭氧发生量符合环境要求。空气净化器在2档运行时,CADR和净化效能均较大。     

风量调节方式对室内污染物浓度的影响分析

针对不同室外空气质量条件,利用MATLAB/Simulink分别对新回风比例不变、新风量不变改变回风量、回风量不变改变新风量的变风量空调系统室内PM_(2.5)质量浓度和CO2体积分数进行了模拟分析。模拟结果表明:对于新回风比例不变的系统,室内PM_(2.5)稳定质量浓度与室外PM_(2.5)质量浓度有关,而与回风量和额定回风量的比值R1无关;但室内PM_(2.5)质量浓度下降速度与R1有关。对于新风量不变改变回风量的系统,室内PM_(2.5)质量浓度主要受回风量影响。对于回风量不变改变新风量的系统,室外PM_(2.5)质量浓度和新风量是影响室内PM_(2.5)质量浓度的主要因素。     

Chemical characteristics of aerosols at coastal station in Hong Kong.Ⅱ.Environmental behavior of trace elements during the April 1995 to April 1996

An one-year of sampling aerosol program was carried out during the period of April 1995 to April 1996 at coastal region, Cape D‘Aguilar, in Hong Kong. The trace element composition of aerosol particles(TSP and PM10) were measured and analyzed by using the Instrumental Neutron Activation Analysis(INAA) and Inductive Couple Plasma-Mass Spectrometry(ICP-MS) techniques. The results showed that the polluted elements such as: V, Zn, As, Pb, Cd, Sb, I, Se, Bi, with high enrichment factor( E. F) values, are derived from anthropogenic sources ,while Sc, AI, Fe, Mn, Sm, La, Sr are less than 10 in E. F, these elements are related the crust and soil. The concentration of the trace elements are present seasonal variation i.e. summer low and winter high, whereas the V or noncrustal V(V^* ) present summer high and winter low, this phenomenon might be explained by local or regional oil combustion sources. Use three type of elemental ratio, e.g. La/Sm, Mn^*/V^* and Bi/Al indicate that both TSP and PM10 of La/Sm ratios are mainly related to soil and dust, Mn^*/V^* are probably represent fossil combustion and Bi/Al are possibly associated with refuse incineration, ferromanganese alloys and aluminum production. The varimax rotation factor analysis for trace elements was performed. By means of the absolute principal component analysis (APCA) and multiple regression, the contribution of trace elements to possible sources and overall means of trace elements were estimated. The results showed that the present station is impacted by the anthropogenic species, although the quantities are different during the summertime and wintertime.     

南京市可吸入颗粒物数浓度变化及尺度分布

采用南京市近期颗粒物粒子数浓度的观测资料，对颗粒物中可吸人颗粒物(PM10)进行了分析。结果表明：近10年来南京地区可吸人颗粒物的数浓度显著增加，平均增加近4倍；PM10数浓度主要受生产活动和大气层结变化影响，日变化呈现两高两低变化趋势。观测期间，可吸人颗粒物中主要成分是细粒子，PM25数量平均占PM10总数量的99％以上。     

大连市“十五”期间大气环境中SO2、NO2、PM10污染状况分析

根据大连市大气污染特点，通过对SO2、NO2、PM10年均值、月均值以及各功能区年均值和采暖期与非采暖期的污染状况进行玢析。得出大连市大气环境中SO2、NO2、PM10的主要来源及污染程度。结果表明，3项污染指标的年均值均符合国家环境空气质量二级标准：SO2呈缓慢增长趋势，NO2、PM10无明显变化趋势。