Identifier

etd-04242012-000041

Degree

Master of Science in Civil Engineering (MSCE)

Department

Civil and Environmental Engineering

Document Type

Thesis

Abstract

Fixed-film biological treatment processes, commonly referred to as biofilters, have been applied to successfully treat a wide variety of volatile organic compounds (VOCs) present in air emitted by a wide variety of industrial operations. The ability of biofilters to treat some classes of VOCs, however, has not been well established. In particular, the performance of biofilters treating sesquiterpenes has not been widely studied. In the research described herein, a laboratory-scale biofilter was operated to treat a synthetic waste gas stream containing â-caryophyllene, a sesquiterpene emitted by conifer trees and industrial wood processing operations. An enrichment culture developed in an initial experiment conducted in a sparged gas reactor was used to seed a laboratory-scale biofilter that was subsequently operated under mesophilic conditions for more than 262 days. During the first 244 days of continuous operation, there were seven distinct periods of biofilter operation, designated as Periods 1, 2, 3A, 3B, 4, 5A, and 5B. Period 1 was the initial period of biofilter operation following startup, and Periods 2 to 5 involved progressively higher gas flow rates and pollutant loading rates. To assess the impact of nutrient supply on biofilter performance, the concentrations of nutrients supplied to the biofilter changed at various time intervals. An additional experiment was conducted to evaluate the capacity of the system to recover following a 14-day interval of no â-caryophyllene supply. Collectively, data presented herein demonstrated that â-caryophyllene can be successfully treated using biofilters. This expands the classes of compounds successfully treated in biofilters to include sesquiterpenes. Data reported herein also demonstrate that local nutrient limitations can cause diminished treatment performance, a phenomenon observed in previous studies involving other pollutants. The biofilter was capable of relatively rapid recovery following resumption of pollutant loading following a 14-day starvation interval.

Date

2012

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Moe, William M

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