Date of Award

Spring 1-1-2015

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Civil, Environmental & Architectural Engineering

First Advisor

Lupita D. Montoya

Second Advisor

Angela R. Bielefeldt

Third Advisor

Jorge M. Vivanco

Abstract

Formaldehyde is a common indoor air pollutant, which poses negative health effects to building occupants, and it is found in commercial, residential, and occupational spaces. Its removal is usually achieved by augmenting ventilation rates, an approach that is energy-intensive. Formaldehyde is a volatile organic compound (VOC) that is very hydrophilic and can be sorbed onto organic materials and porous media sorbents. The objective of the research is to quantify the rate of formaldehyde sorption on several porous media and determine if microbial degradation could occur in these media. Four porous media (Growstone, Hydroton expanded clay, coco coir, and activated carbon) were tested and found to have average sorption potentials of 0.241, 0.572, 42.36, and 174.13 mg/g media, respectively. In addition, microbial communities extracted from several soils and these porous media were tested for their potential to survive on various levels of formaldehyde. One soil, thought to be exposed to formaldehyde, produced microbes able to survive on LB agar medium containing 20 mM (736.7 ppm) formaldehyde, but these CFU’s were absent when the same soil was tested nine months later. Neat (not inoculated with microbes) porous media were also tested for their formaldehyde-resistant microbial communities before and after exposure to gaseous formaldehyde. Activated carbon, Growstone, and Hydroton expanded clay were largely sterile both before and after exposure. Coco coir exhibited colony growth at 1 mM formaldehyde before exposure and a 156.7% increase in colony counts on 1 mM plates after exposure to gaseous formaldehyde. The use of low-cost porous media such as coco coir should be further investigated as an alternative for the removal and degradation of formaldehyde in indoor environments.

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