Removal Efficiency of Bimodal PM2.5 and PM10 by Electret Respirators and Mechanical Engine Intake Filters

Abstract

As China is receiving an economic boom, PM (particulate matter) pollutions not only have become a serious regional problem but also frequently impacted its neighboring counties, e.g., Korea and Japan. In addition to its adverse effects on human health, the on-and off-road engines operated in ambient can also be affected. In this study, a simple system for generating simulated ambient bimodal PMs comprising fine (PM 2.5 ), coarse (PM 2.5-10 ) particles was developed for evaluating the initial efficiency of seven respirator and four engine intake filters. In addition to the size fractional efficiency curves for each filter media determined from the SMPS (scanning mobility particle sizer) and APS (aerodynamic particle sizer), both number and mass based efficiency of these filters for PM 2.5 , PM 2.5-10 and PM 10 were also obtained to evaluate their performances against ambient PM pollutions. Data showed that the engine intake filters had a low efficiency for both mass and number based PM 2.5 , which was only about 25-30%. However, there was a large difference between their number and mass based PM 10 efficiency. The former was much lower than the latter because these filters are with high efficiency only for coarse particles. Besides, the most of particles in number was resided in the fine size range while the mass was in coarse size range. For the respirator filtration tests, results showed that most of them can effectively remove both PM 2.5 and PM 10 , in which the mass efficiency was always higher than that of number. The PM 2.5 number efficiency results showed there are three out of seven respirator filters are with N-95 rated level, in which the efficiency of their most penetrating particle size is higher than 95%. The current simple experimental system could be applied to examine different purpose filters which protect human health and outdoor engines against ambient PM 2.5 and PM 10 .

Life Cycle Assessment of Silicon-Nanotube-Based Lithium Ion Battery for Electric Vehicles

“…To extrapolate the emissions for potential industrial application, we applied the 90% removal efficiency for volatile organic carbon in industry 54 and 30% removal rate for PM 2.5 . 55 In this study, we have derived the emission factors of 0.063% and 0.055% for cyclohexane and diethyl amine respectively as well as 0.12 g PM 2.5 emissions kg −1 SiNT synthesis. The resultant effluent collected from the SiNT synthesis contains magnesium ions, nickel ions, dissolved organic nitrogen (as in hydrazine and diethyl amine).…”

Characterization of Aerosol Composition, Concentration, and Sources in Bukhansan National Park, Korea

“…대기 중의 초미세먼지는 직접적으로 흡수 또는 산란 을 통해 시정에 영향을 주며 가시도를 저하시키고 구 름 응결핵으로 작용하면서 기후변화를 초래한다 (Gao et al, 2015;Rastogi et al, 2014;Tao et al, 2014 (Tang et al, 2017;Chen et al, 2016). 국내에서는 초미세먼지를 규제하기 위해 2015 년에 대기환경기준 (PM 2.5 50 μg/m 3 )을 도입하였으며 2018년 현재 초미세먼지 규제 기준은 35 μg/m 3 으로 강 화되었다 (Park et al, 2017;Ham et al, 2016 (Nowak et al, 2013;Kim et al, 2012;Lee et al, 2008).…”

Capture of Sub-500 nm Particles Using Residential Electret HVAC Filter Media-Experiments and Modeling

“…Here, the KCl particles were generated by an Collision type atomizer (Model 3079, TSI Inc., Shoreview, MN, USA) and classified into 30 to 500 nm monodisperse particles by a long DMA (Model 3081, TSI Inc., Shoreview, MN, USA). The details on the furnace temperature and solution concentration of KCl can be found elsewhere (Chang et al, 2015;Chen et al, 2016). All the particles were brought to Boltzmann equilibrium before entering the filter holder where the round flat sheets of filter media were mounted.…”

“…As performing a high efficiency while maintaining a low pressure drop, electret HVAC filter media are widely used to remove airborne particles (Romay et al, 1998). The peak sizes of ambient fine and coarse modes (volume-based size distribution) around the world were frequently measured with ~0.2-0.7 and ~3-20 µm, respectively (Whitby et al, 1972;Kanaoka et al, 1987;Harrison et al, 2000;Chen et al, 2010;Chen et al, 2016). The coarse particles can settle by themselves or easily captured by filter media while the fine particles are more difficult to be removed.…”