Degree Type

Thesis

Date of Award

2016

Degree Name

Master of Science

Department

Civil, Construction, and Environmental Engineering

Major

Civil Engineering (Environmental Engineering)

First Advisor

Timothy G. Ellis

Abstract

The aim of this research was to demonstrate the feasibility of the static granular bed reactor (SGBR) as a replacement for the conventional mixed and heated anaerobic digester typically operating at municipal wastewater treatment plants (WWTP). The static granular bed reactor (SGBR) is a high rate anaerobic granular reactor. The SGBR operates at a short hydraulic retention time (HRT) (i.e 1 to 2 d) while maintaining a long solids retention time (SRT). Conversely to conventional digesters the SGBR separates the SRT from the HRT, reducing energy and volume requirements. The SGBR is downflow reactor with a dense bed of granules that entraps particles which helps to facilitate hydrolysis. Anaerobic treatment of primary and secondary municipal sludge was studied with a laboratory and pilot-scale SGBR at organic loading rates (OLR) from 2.8 ± 0.9 to 5.5 ± 1.7 g COD/L·d and 3.3 ± 2.0 g COD/L·d, respectively. The results of this research demonstrated the SGBR system's potential to be a practical and competitive alternative to conventional anaerobic digestion of wastewater sludges. The laboratory (76 ± 4%) and pilot-scale (71 ± 0.4%) SGBR produced a biogas with a higher methane content than the conventional anaerobic digester tested (59 ± 2.8%). Effluent VFA concentrations remained below 40 mg/L as HAc, indicating the potential to reduce process instability due to the buildup of intermediates. The low VFA concentrations of the SGBR's effluent also reduces odors compared to the liquid streams of conventional anaerobic digesters. The SGBR produced an effluent with low organic matter; average TSS and COD removal efficiencies remained above 90%.

Copyright Owner

Tyler J. Biese

Language

en

File Format

application/pdf

File Size

84 pages

Share

COinS