Biological nutrient removal in bench-scale membrane bioreactor and full-scale sequencing batch reactor under various configurations and conditions

Abstract

for allowing me to take their valuable time. I must thank Dr. Ahmet YUCEER from Cukurova University, Turkey, who has always encouraged me to have a graduate degree in the U.S. Dr. Ertan ARSLANKAYA also deserves thanks for his critique of my work during the experimental stage as well as sharing his expertise in statistical analysis and kinetic modeling. Patrick Brown is also appreciated for his help in laboratory work. Finally, I would like to thank the Higher Education Council of Turkey for making available the Future Faculty Fellowship and Scholarship fund that financed my work at Iowa State University and partial financial support by ISU-IPRT and Fox Engineering and Associates for the full-scale sequencing batch reactor study.

Influence of anaerobic and anoxic hydraulic retention time on biological nutrient removal in a membrane bioreactor

“…The elimination of the clarifier also allows for operation of the system without regard to the settleability of the biomass and permits the HRT to be controlled completely independently of the SRT (Visvanathan et al, 2000). Many MBRs are operated at a relatively high SRT of 20-30 days, although it is possible to operate at very high SRTs of up to 75 days and maintain satisfactory treatment performance (Ahn et al, 2003;Ersu, 2006;Zhang et al, 2006). Operation at high SRT lowers sludge production and reduces the associated costs for sludge disposal (Trussell et al, 2005).…”

“…Ahn et al (2003) reported total nitrogen removal of 60% and total phosphorus removal of 93% at 70 days SRT. Ersu (2006) investigated SRTs from 10 to 75 days using synthetic municipal wastewater and reported optimum performance (78% TN, 81% TP removal) at an SRT of 50 days. Innocenti et al (2002) reported promising MBR performance (85% TN, 89% TP removal) at an SRT of 190 days.…”

“…The majority of published studies have used relatively short to medium SRTs from 10 to 25 days. Recent research has shown superior removal performance at much higher SRTs of 50-75 days (Ersu, 2006;Ahn et al, 2003;Zhang et al, 2006). There is a need to determine the effect of high SRT on other operating parameters such as HRT, C:N:P ratios, and microbial populations.…”

“…All lab experiments were conducted in a bench-scale membrane bioreactor system with three separate reactors: anaerobic, anoxic, and aerobic (Figure 3.1). The reactor design was based on previous work by Ersu (2006) who found that one optimal recycle arrangement was membrane permeate recycled to the anoxic reactor and return mixed liqour recycled to the anaerobic reactor, both at 100% of influent flow rate and at a solids retention time of 50 days (Ersu, 2006). The anaerobic and anoxic reactors were both cylindrical shaped with a total volume of 12 L each and employed magnetic stirrers to provide complete mix conditions.…”

“…Prior to creating the experimental design, trials using the computer modeling software Biowin® version 2.2 (Envirosim Inc., Ontario, Canada) and a review of current literature were carried out to narrow the range of hydraulic retention times to be tested. Based on previous work, Biowin® (version 2.2) has been shown to not accurately predict the behavior of biological phosphorus removal in MBRs, particularly at high SRTs (Ersu, 2006), but must be properly calibrated before it can be used.…”