Inorganic and organic chemical characteristics and sources of suspended particulate matters in Ulaanbaatar, Mongolia

We are studying the effects of thermal moisture swing air-cleaning method on removal of suspended particulate matter, SPM. This method continuously humidifies sample air with heating and dehumidifies it by cooling, in a channel. It was experimentally demonstrated that the thermal moisture swing method reduces SPM suspended in sample air. The experimental result showed reduction of SPM above 10 nm in particle size, and the removal ratio increased with intensifying the thermal moisture swing. The SPM removal mechanism of this method was theoretically estimated. The estimation suggests that the reasons for the SPM reduction are suction flow accompanying condensation and thermophoresis. These phenomena would transport SPM to cooling wall of the dehumidifier. Also, diffusional deposition and gravitational sedimentation would transport SPM to the wall of the channel. And, the transported particles are separated from the air with adhering on the wall. We estimated the effects of these phenomena on SPM removal using simple model and energy consumption. The estimation qualitatively agreed with the experimental result.

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Multimodality of a particle size distribution of cohesive suspended particulate matters in a coastal zone

Journal of Geophysical Research Atmospheres ◽

10.1029/2011jc007552 ◽

2012 ◽

Vol 117 (C3) ◽

pp. n/a-n/a ◽

Cited By ~ 45

Author(s):

Byung Joon Lee ◽

Michael Fettweis ◽

Erik Toorman ◽

Fred J. Molz

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Coastal Zone ◽

Particulate Matters ◽

Suspended Particulate ◽

Suspended Particulate Matters

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Variation in Size Distribution of Suspended Particulate Matters in Air With Humidity Swing Operation

Volume 7: Fluid Flow, Heat Transfer and Thermal Systems, Parts A and B ◽

10.1115/imece2010-39508 ◽

2010 ◽

Author(s):

Nagisa Onoda ◽

Osamu Nakabeppu

Keyword(s):

Particulate Matters ◽

Nuclear Condensation ◽

Cleaning Method ◽

Air Cleaning ◽

Submicron Size ◽

Suspended Particulate ◽

Spm Concentration ◽

Suction Flow ◽

Nano Size ◽

Suspended Particulate Matters

The aim of this study is to develop a new air cleaning method being applicable to suspended particulate matters (SPM) of wide sizes. We experimentally studied about the effects of a humidity swing operation where sample air is continuously humidified with heating and dehumidified with cooling. The total of SPM concentration of sample air decreased with the humidity swing operation; however, the concentration of SPM from 0.3 to 1 μm markedly increased. Suction flow accompanying condensation, cohesion and thermophoresis were considered as the SPM reduction effects. It would appear that the nano-size SPM grew to submicron size by nuclear condensation and submicron size SPM increased. The experimental results showed that the SPM concentration of 0.3 μm or less decreased by 89% and the total of that decreased by 80%. The applicability of the humidity swing operation to removal of SPM including nano size SPM was shown by the results. Also, exponential reduction of the SPM concentration was demonstrated with applying the repeated humidity swing operation in a circulation air-cleaning apparatus. This method is expected to become effective air cleaning method applicable to wide size range of SPM.

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