DOI

10.17077/etd.e14kkfba

Document Type

Thesis

Date of Degree

Fall 2017

Degree Name

MS (Master of Science)

Degree In

Biomedical Engineering

First Advisor

Thomas M. Peters

First Committee Member

Elizabeth A Stones

Second Committee Member

Michael Mackey

Abstract

Traditional aerosol samplers are limited in their abilities to collect large quantities of particulate matter due to their low flow rates, high pressure drops, and are noise intrusiveness. The goal of this study was to develop an alternate aerosol sampler using electrostatic precipitation technology that was safe and not noise intrusive to be deployed in homes. The O-Ion B-1000 was selected as the most suitable electrostatic precipitator (ESP) for achieving the goal of this study because of its affordability, the design of its collection electrode and its high flow rate. The collection efficiency of the ESP was assessed for three aerosols; Arizona Road Dust (ARD), NaCl and diesel fumes. ARD was found to have the highest average collection efficiency (65%) followed by NaCl (43%) and lastly diesel fumes (41%).

A method for recovering the particulate matter deposited on the collection electrode was developed. The dust collected on the electrode was recovered onto polyvinyl chloride (PVC) filters moistened with deionized water. Additionally, the recovery of the three test aerosols, ARD, NaCl, and diesel fumes, from the collection electrode was assessed. A gravimetric analysis was done to determine the amount of dust recovered. The collection efficiency was used to calculate the amount of mass expected on the filter for a particular aerosol. NaCl had the highest recovery at 95% recovery, followed by ARD (73%) and lastly diesel fumes (50%). Two identical ESPs were also deployed in an office and in a bedroom, 104.47 mg and 9.64 mg of particulate matter (PM) was recovered respectively.

The noise and ozone level produced by the ESP was evaluated to determine the ESP’s viability as a household aerosol sampler. The ESP’s high setting had a noise level of 45.8 dB and ozone generation rate of 0.036 mg/min. The results of the calculation showed that in an averaged size unventilated room (6.10 m × 6.10 m × 2.44 m), it would take 6 hours and 53 minutes for the ozone levels to reach the recommended maximum exposure limits per National Ambient Air Quality Standards (NAAQS). Additionally, a ventilation of 230 L/min is needed in order to prevent the ozone levels generated by the ESP from exceeding maximum exposure limits per NAAQS.

Overall, the O-Ion B-1000 met the criteria of collecting 1 mg of PM in a 24 hour sampling for ARD and NaCl. Diesel fumes however, required 30 hours to collect 1 mg of PM. The noise levels generated by the ESP set on high was one dB above the Environmental Protection Agency (EPA) standards for indoor noise limit. However, the noise is proportional to inverse distance squared; the ESP should not pose a problem during household deployment. Ozone generated by the ESP was also found to be below 0.07 ppm as set by the EPA with an average ventilation of 230 L/min. The average ventilation of a household is 1500 L/min, thus the ozone generated by the ESP would not surpass 0.07 ppm. However, the ESP should not be deployed in unventilated rooms for a period of more than 6 hours and 53 minutes.

Keywords

Aerosols, Aerosol Samplers, Air Purifiers, Collection Efficiency, Electrostatic Precipitator, Particulate Matter

Pages

ix, 77 pages

Bibliography

Includes bibliographical references (pages 73-77).

Copyright

Copyright © 2017 Chun Hoe Ong

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