Date of Award
8-2019
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Environmental Engineering and Earth Sciences
Committee Member
Sudeep Popat, Committee Chair
Committee Member
David A. Ladner
Committee Member
David L. Freedman
Abstract
Anaerobic membrane bioreactors (AnMBRs) offer a potentially energy efficient
means of treating domestic wastewater, but their performance with seasonal temperature
variations must be understood to determine their feasibility in replacing conventional
activated sludge processes. A bench-scale AnMBR treating primary clarifier effluent
from a WWTP in Greenville, SC was found to achieve a similar chemical oxygen
demand (COD) removal during operation at 35°C, 25°C, and 15°C, with average
permeate COD concentrations of 70.5 mg/L, 60.7, and 77 mg/L respectively. Methane
yields averaged 109 L CH4/kg CODremoved at 35°C, 114 L CH4/kg CODremoved at 25°C,
and 64 L CH4/kg CODremoved at 15°C. Reduced methane yield is attributed to a decrease
in methanogen abundance, seen by an almost 3-fold decrease in mcrA gene abundance
during operation at 15°C. The conclusion that the AnMBR achieves similar methane
yields at 35°C and 25°C is significant because substantial energy savings could be
obtained from not heating the reactor to 35°C as is common in conventional anaerobic
processes. Energy savings could especially be significant if the wastewater is already
near 25°C for a portion of the year. By understanding the microbial components of
AnMBR treatment through molecular microbial analysis and relating them with the
performance of the AnMBR at different temperatures, we can better understand the
functionality of specific microbial communities and therefore better inform, operate, and
design anaerobic resource recovery processes for maximum effectiveness.
Recommended Citation
Evans, Emily Blair, "The Effect of Temperature on the Performance of Anaerobic Membrane Bioreactors for Treatment of Domestic Wastewater" (2019). All Theses. 3186.
https://open.clemson.edu/all_theses/3186