Microorganisms and Functional Genes Associated with Cometabolic Degradation of 1,4-Dioxane in Biologically-Active Carbon Biofilters Applied for Potable Reuse Treatment

1,4-dioxane is a probable human carcinogen frequently found in water and wastewater systems at concentrations above the EPA one-in-one-million cancer risk level of 0.35 ug/L. 1,4-dioxane is not well removed through conventional treatment methods due to its polarity and resistance to biodegradation, especially when present at low (μg/L) concentrations. Cometabolic degradation of 1,4-dioxane has been achieved in groundwater remediation by stimulating bacteria carrying cyclic ether-degrading soluble diiron monooxygenases (SDIMOs) through the addition of simple alkane gases, such as propane. A recent pilot-scale study demonstrated that addition of such co-substrates prior to biological active filtration (BAF) holds potential as a novel potable reuse treatment approach that can effectively remove 1,4-dioxane. Characterization of the microbial communities associated with propane-induced cometabolism of 1,4-dioxane has largely been limited to culture or polymerase chain reaction (PCR)-dependent methods, which are highly limited in throughput, generally providing information about one organism or one gene at a time. Shotgun metagenomic sequencing is a high-throughput nontargeted means of broadly profiling microbial taxa and functional genes involved in various metabolic processes. In this thesis, methods for DNA extraction from granular activated carbon applied to full-scale BAF amended with propane for the purpose of 1,4-dioxane cometabolism were optimized and metagenomic sequencing was performed. Insights were gained into the microbes and functional genes involved in 1,4-dioxane biodegradation, furthering our understanding of a potentially powerful new water reuse treatment technology that effectively polishes recalcitrant contaminants.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Environmental Sciences and Engineering

Department dc:contributor.department

Environmental Science and Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2024

Author dc:creator

• Scott, Katherine Denise

Chair dc:contributor.committeechair

• Pruden, Amy

Committee members dc:contributor.committeemember

• Widdowson, Mark A.
• Bott, Charles B.

• Metagenomics
• Biofiltration
• Potable Reuse

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:39686

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/119537