Characteristics Of PM2 Research Articles

2013~2016년 제주 PM2.5 화학조성 변화 및 고농도 발생 특성

2013~2016년 제주 PM2.5 화학조성 변화 및 고농도 발생 특성

감쇄 전반사 FTIR 기법을 이용한 광주광역시 봄철 PM2.5의 화학적 특성 분석

감쇄 전반사 FTIR 기법을 이용한 광주광역시 봄철 PM2.5의 화학적 특성 분석

A study on the Emission Characteristics of FPM and CPM in Power Plants

As people have become more aware of fine particulate matter (PM2.5) recently, there have been growing concerns over the harmful impact of PM2.5 on human health. Since stationary sources are a major source of PM2.5 emission, measures to manage and reduce PM2.5 emission from the stationary sources need to be taken. PM2.5 primary emissions from stationary sources contain a filterable and condensable portion. Filterable PM are particles directly emitted from a stack in a solid or liquid form at stack conditions and captured in the filter of a sampling train. Condensable PM is a material that stays as gas within the stack but is condensed, diluted and/or cooled into solid or liquid particles in the ambient air immediately after discharge from the stack. In this study, the emission characteristics of filterable and condensable PM from power plants are investigated. The average filterable PM2.5 concentration from two coal-fired power plants ranged from 1.85 to 2.02 mg/m3 and that from an LNG power plant was 0.02 mg/m3. The average condensable PM2.5 concentrations from the coal-fired power plants and the LNG plant were 9.08-12.20 mg/m3 and 1.02 mg/m3, respectively.

An investigation on characteristics of PM<sub>10</sub> concentration distribution in school environment using meta-analysis

An investigation on characteristics of PM<sub>10</sub> concentration distribution in school environment using meta-analysis

Analysis of Chemical Components and Sources of PM2.5 During Autumn and Winter in Yangquan City

PM2.5 samples were collected from October 15, 2017 to January 23, 2018 in the Yangquan urban area. The characteristics of PM2.5 and its main chemical components on clean and polluted days were analyzed, and source apportionment of PM2.5 was conducted using enrichment factor analysis (EF) and positive matrix factorization (PMF). The results showed that the ratios of secondary inorganic ions (SO42-, NO3-, and NH4+) to PM2.5 on polluted days was 23.83%, which is 2.43 times higher than that on clean days, indicating that secondary inorganic pollution was more significant on polluted days. The enrichment degree of anthropogenic elements Cd, Sb, Sn, Cu, Pb, Zn, and As on polluted days was higher than that on clean days. The results of the PMF source apportionment showed that the main sources of PM2.5 in Yangquan are coal combustion, dust, motor vehicles, secondary aerosols, and industry, with contributions of 29.26%, 23.83%, 19.34%, 16.01%, and 11.57%, respectively. The contribution of motor vehicle emissions to PM2.5 on polluted days is 20.57%, which is higher than that on clean days (17.82%), while the contribution of coal combustion sources to PM2.5 on polluted days is 23.04%, which is significantly lower than that on clean days (33.75%). The stationary weather on polluted days caused the contribution of motor vehicle emissions to PM2.5 to increase compared with on clean days, while the contribution of coal combustion sources to PM2.5 was decreased. The results show that air pollution control should pay more attention to the control of coal combustion and dust during autumn and winter in Yangquan, and further strengthen the control of motor vehicles to reduce their contribution to pollution.

Functionalized cellulose to remove surfactants from cosmetic products in wastewater

A flocculant composed of paper mulberry dicarboxylic cellulose (PM-DCC) made from using paper mulberry (Broussonetia kazinoki Siebold and Zucc.) has been developed to reduce the amount of inorganic coagulants needed to remove surfactants in wastewater. The characteristics of PM and soda pulp were determined according to the degree of polymerization, α-cellulose, lignin, free sugar, and extract contents. FTIR, XRD, the aldehyde content, the carboxyl content and coagulant-flocculation experiments were conducted to confirm the properties of PM-DCC and paper mulberry dialdehyde cellulose (PM-DAC). A dramatic removal efficiency (95.62 %) was revealed when 0.3 % PM-DCC was added into a linear alkylbenzene sulfonate (LAS) solution with 1% FeCl3·6H2O at pH 2. This means that PM-DCC contributes to both a lower amount of inorganic coagulant needed and a reduction of water pollution by an ecofriendly method.

Estimation of spatially continuous daytime particulate matter concentrations under all sky conditions through the synergistic use of satellite-based AOD and numerical models

Satellite-derived aerosol optical depth (AOD) products are one of main predictors to estimate ground-level particulate matter (PM10 and PM2.5) concentrations. Since AOD products, however, are only provided under high-quality conditions, missing values usually exist in areas such as clouds, cloud shadows, and bright surfaces. In this study, spatially continuous AOD and subsequent PM10 and PM2.5 concentrations were estimated over East Asia using satellite- and model-based data and auxiliary data in a Random Forest (RF) approach. Data collected from the Geostationary Ocean Color Imager (GOCI; 8 times per day) in 2016 were used to develop AOD and PM models. Three schemes (i.e. G1, A1, and A2) were proposed for AOD modeling according to target AOD data (GOCI AOD and AERONET AOD) and the existence of satellite-derived AOD. The A2 scheme showed the best performance (validation R2 of 0.74 and prediction R2 of 0.73 when GOCI AOD did not exist) and the resultant AOD was used to estimate spatially continuous PM concentrations. The PM models with location information produced successful estimation results with R2 of 0.88 and 0.90, and rRMSE of 26.9 and 27.2% for PM10 and PM2.5, respectively. The spatial distribution maps of PM well captured the seasonal and spatial characteristics of PM reported in the literature, which implies the proposed approaches can be adopted for an operational estimation of spatially continuous AOD and PMs under all sky conditions.

Variation characteristics and meteorological influencing factors of PM_(2. 5)mass concentration in Xi'an City from 2015 to 2018

To master the variation characteristics of PM_(2. 5) mass concentration in Lianhu district and Yanta district of Xi'an City and its relationship with meteorological conditions. From 2015 to 2018, according to the environmental monitoring data of six main urban areas in Xi'an City in 2012, including NO_2, SO_2, PM_(10), PM_(2. 5), CO and O_3, air samples were collected in the relatively heavy polluted Lianhu district and the relatively light Yanta district of Xi'an City. The mass concentration test of PM_(2. 5) was carried out in accordance with the Ministry of Environmental Protection's "Determination of atmospheric articles PM_(10) and PM_(2. 5) in ambient air by gravimetric method "(HJ 618-2011). According to the Ambient air quality standards(GB 3095-2012), the average daily secondary concentration limit(75 μg/m~3) was used for statistical analysis and evaluation according to different annual, regional and seasonal test result. Meteorological data of Xi'an City were collected, including daily average temperature, daily average pressure, daily average relative humidity, daily average wind speed, daily precipitation, maximum temperature and minimum temperature, and the relationship between PM_(2. 5)concentration and meteorological factors was analyzed. A total of 660 air samples were collected and qualified, the median concentration of PM_(2. 5) was 71 μg/m~3. 356 air samples were qualified, and the pass rate was 53. 94%. The sample pass rate for each year from high to low was 2017>2018>2016>2015(P<0. 001), The average level of PM_(2. 5) mass concentration from high to low was 2015>2016>2017>2018(P<0. 001). There was no significant difference in the sample pass rate and PM_(2. 5)mass concentration between Lianhu district and Yanta district(P>0. 05). The qualified rate of samples from high to low in different seasons was summer>spring> autumn>winter(P<0. 05). The average concentration of PM_(2. 5) in different seasons from high to low was winter>autumn>spring>summer(P<0. 001). Mean temperature, mean air pressure, average wind speed, average relative humidity, precipitation and lowest temperature were significantly correlated with PM_(2. 5) mass concentration(P<0. 001). The determination coefficients of multiple regression analysis of meteorological factors in Lianhu and Yanta regions were 0. 390 and 0. 373, respectively. The air quality in Lianhu district and Yanta district of Xi'an City had improved year by year, and the pollution of PM_(2. 5) in autumn and winter was more serious. Meteorological conditions affected the concentration level of PM_(2. 5) in the atmosphere.

Exhaust characteristics of PM from unsteady pool flame

Exhaust characteristics of PM from unsteady pool flame

北京野鸭湖湿地观测站PM<sub>2.5</sub>变化特征及其与气象因素的关系

北京野鸭湖湿地观测站PM<sub>2.5</sub>变化特征及其与气象因素的关系

Oxidation characteristics of PM formed by quenching process of a laminar diffusion flame

Oxidation characteristics of PM formed by quenching process of a laminar diffusion flame

Corrigendum: Experimental study on production and emission characteristics of PM 2.5 from industrial fluidized bed boilers

Requests that it is necessary to clearly define names of two Corresponding authors of the paper EXPERIMENTAL STUDY ON PRODUCTION AND EMISSION CHARACTERISTICS OF PM2.5 FROM INDUSTRIAL FLUIDIZED BED BOILERS by Songsong ZHANGa, Qian DUb* , and Guoli QIa <br><br><font color="red"><b> Link to the corrected article <u><a href="http://dx.doi.org/10.2298/TSCI190828001Z">10.2298/TSCI190828001Z</a></b></u>

DANGERS AND PREVENTIVE MEASURES DURING PRODUCTION OF POLYMERIC MATERIALS BASED ON POLYAMIDES

In the article were considered dangers that arise up during production and processing of polymeric materials. Actuality of theme is related to that nowadays production of polymeric materials occupies one of the leading places in chemical and petrochemical industry. With the aim of improvement operating properties of polymeric materials will be added to their composition different additives (curing agents, plasticizers, catalysts, greases, stabilizators and other auxiliary substances) or fillers (particles, or fibres of different sizes and forms). Such approach allows considerably improve physico-mechanical and tribological characteristics of PM, however additives, fillers and polymers in the moment of their processing can have bad influence on the human body. Character of unfavorable action of synthesis products of PM on the human body is in the first turn determined by toxicity of monomers that are used for their producing. Plasticizers can be the reason of poisoning, as additives are toxic, and their operating on the organism can be even more expressed, than polymer’s one. Both the production of polymeric materials and their processing in products, accompanied by liberation in the air of working zone gaseous substances and dust, various by the nature of action, would cause to different changes in the organism of workers, depending on their concentration and duration of influence. The range of these violations is wide enough - from the changes of separate indexes of homoeostasis to development of serious and chronic intoxications and diseases, the clinical displays of that depend on predominance of those or other components that are used for the production of polymeric materials and processing products therefrom. As monomers are the basic components of these materials, so exactly from character of their operating on the organism and depends clinical presentation of professional pathology, that will progressed of workers. To avoid a traumatism, negative influence on health and professional morbidity is possible by sticking technologies of production of polymeric materials and technicians of safety, that are considered in this article.

Analysis of ship emission characteristics under real-world conditions in China

The actual emission characteristics of CO, THC, NOx, and PM from 50 ships were tested by a portable emission measurement system. Statistical analysis of emission data was carried out based on model years and engine types. The results show that with the increase of the model year, the specific emissions of pollutants increase gradually, that is, the stage I ships (before 2000 years) emit more pollutants. For CO, the specific emissions for stage Ⅱ ships (between 2001 and 2010 years) increase by 3.99%–26.39% compared with those for stage Ⅲ ships (between 2011 and 2016 years), and for stage I and Ⅱ ships, the maximum specific emissions increase by 25.34%–36.95 under the same operating modes; The specific emissions of THC are similar to those of CO. The specific emissions of THC increase by 45.84%–52.97% for stage I and Ⅱ ships and the weighted emissions of stage Ⅱ ships are 9.37% higher than that of stage Ⅲ. For NOx, the specific emissions of stage I, Ⅱ and Ⅲ ships are gradually reduced by 1.64%–13.44% and 6.83%–23.19% respectively, and the specific emissions under cruise condition are increased by 16.15%–36.47% compared with maneuvering condition. Due to the limitation of fuel products and test methods, PM emission characteristics are slightly different from other pollutants for different stage ships, but weighted emissions considering errors are reduced by 22.49%–25.59%. For different engine types, the specific emissions of high speed engines are higher than those of medium speed engines, especially for CO and THC pollutants, which are 16.05%–36.61% and 6.52%–73.31% higher respectively; On the contrary, for NOx, the emissions for each stage ships are reduced by 8.21%–8.82% compared with those for other stages, and PM has no consistent trend. At the same time, compared with foreign experimental data (European, USA, Sweden, et al.), the emissions of domestic ships, traveling on major routes (Yangtze river basin and Shandong coastal area and so on) in China, are about 1.1–5.11 times than that of other countries.

Characteristics of PM2.5 at a High-Altitude Remote Site in the Southeastern Margin of the Tibetan Plateau in Premonsoon Season

The Tibetan Plateau (TP) is one of the world’s most sensitive areas for climate change. Previous studies have revealed that air pollutants emitted from South and Southeast Asia can be transported to and have a negative impact on the TP. However, the majority of the investigators have focused on the pollutant transport processes from South Asian regions (i.e., India and Bangladesh) and parts of Southeast Asia, while the regions adjacent to the southeast fringe of the TP (i.e., Burma and the Sino-Burmese border) have been neglected. Here, fine particulate matter (PM2.5) samples were collected during the period 11 March to 13 May 2018 at Gaomeigu, a high-altitude remote site in the southeastern margin of the TP. Characteristics, sources of PM2.5, and the potential source regions for different chemical components were investigated. During the sampling time, PM2.5 mass loadings ranged from 3.79 to 54.57 µg m−3, with an arithmetic mean concentration of 20.99 ± 9.80 µg m−3. In general, major peaks of organic carbon (OC) and elemental carbon (EC) always coincided with high loadings of K+ and NO3−, which implies that common combustion sources caused these species’ concentrations to covary, while the daily variations of crustal elements showed different trends with the other chemical compositions, suggesting different source regions for crustal materials. Five source factors were identified as possible aerosol sources for PM2.5 by positive matrix factorization (PMF). They are the mining industry (5.3%), characterized by heavy metal elements; secondary formation (18.8%), described by the high concentrations of NH4+ and SO42−; traffic-related emissions (26.7%), dominated by carbonaceous species (especially soot-EC) and some metal elements; fugitive dust (15.2%), represented by crustal elements (Ti, Fe, and Mn), Ca2+, and Mg2+; and biomass burning (34.0%), which is typified by high concentrations of K+, NO3−, char-EC, primary OC, and secondary OC. The concentration-weighted trajectory (CWT) analysis results showed that the northeast part of Burma is the potential source region for high concentrations of EC and NO3− due to biomass burning emissions, while the tourism industry surrounding Gaomeigu gave strong grid cell values of SO42− as well as moderate values of EC and NO3−. Moreover, the mining industry in the southwest direction of Gaomeigu has important impacts on the zinc concentrations.

Characteristics of PM2.5 and SNA components and meteorological factors impact on air pollution through 2013–2017 in Beijing, China

Beijing, one of the world's largest cities, has been tackling its severe air pollution problems in the past decades, and achieved pronounced reduction on PM2.5 concentration from 99.4 μg/m3 to 69.4 μg/m3 during 2013–2017. This study focused on the variation trends of SO42−, NO3− and NH4+ (SNA) of PM2.5 during this effective improvement period, through a five-year PM2.5 sampling project in urban area. Measurement showed that SNA presented a noticeable decline trend, from 16.6 ± 19.8 μg/m3 to 9.7 ± 13.3 μg/m3 for SO42−, from 16.5 ± 16.2 μg/m3 to 13.1 ± 16.9 μg/m3 for NO3−, from 10.2 ± 10.1 μg/m3 to 9.1 ± 9.9 μg/m3 for NH4+. However, their proportions presented different variations, a decline trend from 14.3 ± 7.7% to 12.9 ± 6.6% for SO42−, a raise trend from 15.2 ± 7.2% to 16.0 ± 7.7% for NO3− and from 9.6 ± 3.7% to 11.7 ± 4.4% for NH4+. The concentration and proportion of SNA significantly increased in heavy polluted days (HPD) compared to non-heavy polluted days (NHPD) through 2013–2017. The ratio of NO3−/SO42− was lower in HPD than NHPD in 2013–2015. However, it was generally larger in 2016 and 2017, indicating the importance of NO3− in the formation of PM2.5 pollution. SOR increased obviously through 2013–2017, which was mainly owed to the enhanced atmospheric oxidation and the regional transport related to regional annual emission variations. HPD mainly occurred in autumn and winter, which was generally related to the south and east wind. RH was a major cause for SNA pollution. Higher increment of SNA concentration as well as SOR and NOR was observed when the RH increased from 40-60% to 60–80%.

Investigation of magnetization characteristics of variable flux PM based on a Fourier-fitting hysteresis model

This paper investigates the magnetization characteristics of variable flux permanent magnet (VF-PM) by using a simplified C-core magnetizer device with AlNiCo PMs. A combined methodology with magnetic circuit model, finite element analysis and Fourier series fitting hysteresis model is proposed. By means of the magnetic circuit analysis, the basic sizing parameters of the device are designed for the prototype manufacturing. A simple experimental setup including a device prototype, a Gaussmeter and H-bridge-converter-based magnetizing circuit is established. Then several experimental schemes are conducted to research the magnetization characteristics. According to the experimental results, a new numerical hysteresis model of AlNiCo PMs is proposed based on Fourier-fitting functions, which can be employed to correct the hysteresis model parameters used in finite element (FE) simulation. Finally, the correctness of the proposed Fourier-fitting hysteresis model (FFHM) is experimentally verified by the test results.

Characteristics of PM2.5 Pollution and the Efficiency of Concentration Control During a Red Alert in the Beijing-Tianjin-Hebei Region, 2016

The Beijing-Tianjin-Hebei (BTH) region experienced a heavy pollution episode in December 2016. Beijing and Tianjin issued a red alert from 20:00 December 16 to 24:00 December 21, while every city in Hebei Province (except Zhangjiakou, Chengde, and Qinhuangdao) issued a red alert from 00:00 December 16 to 18:00 December 22. In order to study the process of heavy pollution and the effect of implementing emergency measures, pollutant concentrations, meteorological conditions, air mass transmission and region transmission, and control effects were analyzed based on environmental monitoring data and simulation. Mean PM2.5 concentrations during the heavy pollution episode in each city all exceeded 200 μg·m-3 and the peak value of hourly averaged concentration (834.5 μg·m-3) occurred in Handan. The meteorological conditions during the heavy pollution episode restricted the diffusion of pollutants, with low pressure and air mass transmission exacerbating the problem. The mean fraction of PM2.5 concentrations in local emissions was 47.1%, but this differed between cities due to variable meteorological conditions. The average reduction of PM2.5 concentrations was 27.6%, indicating that the implementation of a red alert measure was effective. If the emergency measures had been implemented a few days earlier, a greater reduction ratio would have been achieved; a 4.4% greater average reduction in PM2.5 concentrations would have occurred if the measures were implemented two days earlier, while taking action three or more days in advance would not have achieved significant improvement.

Characteristics of PM2.5 and Black Carbon Exposure Among Subway Workers

This study aimed to assess the characteristics of exposure to both PM2.5 and black carbon (BC) among subway workers. A total of 61 subway workers, including 26, 23, and 12 subway station managers, maintenance engineers, and train drivers, respectively, were investigated in 2018. Real-time measurements of airborne PM2.5 and BC were simultaneously conducted around the breathing zones of workers. Maintenance engineers had the highest average levels of exposure to both PM2.5 and BC (PM2.5, 76 µg/m3; BC, 9.3 µg/m3), followed by train drivers (63.2 µg/m3, 5.9 µg/m3) and subway station managers (39.7 µg/m3, 2.2 µg/m3). In terms of the relationship between mass concentrations of PM2.5 and BC, train drivers demonstrated the strongest correlation (R = 0.72), indicating that the proportion of BC contained in PM2.5 is relatively steady. The average proportion of BC in PM2.5 among maintenance engineers (13.0%) was higher than that among train drivers (9.4%) and subway station managers (6.4%). Univariate and mixed effect multiple analyses demonstrated the type of task and worksite to be significant factors affecting exposure levels in maintenance engineers and subway station managers. The use of diesel engine motorcars in tunnel maintenance was found to be a key contributor to PM2.5 and BC exposure levels among subway workers.

Characteristics of PM<sub>10</sub> and PM<sub>2.5</sub> Concentrations at Subway Stations in Busan for 3 years (2015~2017)

Characteristics of PM<sub>10</sub> and PM<sub>2.5</sub> Concentrations at Subway Stations in Busan for 3 years (2015~2017)