Influence of a prolonged solid retention time environment on nitrification/denitrification and sludge production in a submerged membrane bioreactor

Desalination ◽  
2009 ◽  
Vol 245 (1-3) ◽  
pp. 28-43 ◽  
Author(s):  
Hay Choon Teck ◽  
Khor Swee Loong ◽  
Darren Delai Sun ◽  
James O. Leckie
2018 ◽  
Vol 77 (6) ◽  
pp. 1505-1513 ◽  
Author(s):  
Yassine Ouarda ◽  
Mehdi Zolfaghari ◽  
Patrick Drogui ◽  
Brahima Seyhi ◽  
Gerardo Buelna ◽  
...  

Abstract In this study, a submerged membrane bioreactor was used to study the effect of low and high bisphenol A (BPA) concentration on the sludge biological activity. The pilot was operated over 540 days with hydraulic retention time and solid retention time of 5.5 hours and 140 days, respectively. As a hydrophobic compound, BPA was highly adsorbed by activated sludge. In lower concentrations, the biodegradation rate remained low, since the BPA concentration in the sludge was lower than 0.5 mg/g TS; yet, at an influent concentration up to 15 mg/L, the biodegradation rate was increasing, resulting in 99% BPA removal efficiency. The result for chemical oxygen demand removal showed that BPA concentration has no effect on the heterotrophic bacteria that were responsible for the organic carbon degradation. In higher concentrations, up to 16 mg of BPA was used for each gram of sludge as a source of carbon. However, the activity of autotrophic bacteria, including nitrifiers, was completely halted in the presence of 20 mg/L of BPA or more. Although nitrification was stopped after day 400, ammonia removal remained higher than 70% due to air stripping. Assimilation by bacteria was the only removal pathway for phosphorus, which resulted in an average 35% of P-PO4 removal efficiency.


2006 ◽  
Vol 53 (11) ◽  
pp. 269-276 ◽  
Author(s):  
C.T. Hay ◽  
D.D. Sun ◽  
S.L. Khor ◽  
J.O. Leckie

A high strength industrial wastewater was treated using a pilot scale submerged membrane bioreactor (MBR) at a sludge retention time (SRT) of 200 d. The MBR was operated at a high sludge concentration of 20 g/L and a low F/M ratio of 0.11 during 300 d of operation. It was found that the MBR could achieve COD and TOC overall removal efficiencies at more than 99 and 98% TN removal. The turbidity of the permeate was consistently in the range of 0.123 to 0.136 NTU and colour254 absorbance readings varied from 0.0912 to 0.0962 a.u. cm−1. The sludge concentration was inversely proportional to the hydraulic retention time (HRT), yielded excellent organic removal and extremely low sludge production (0.0016 kgVSS/day).


2006 ◽  
Vol 53 (6) ◽  
pp. 7-13 ◽  
Author(s):  
H.Y. Ng ◽  
T.W. Tan ◽  
S.L. Ong ◽  
C.A. Toh ◽  
Z.P. Loo

In this study, four similar bench-scale submerged Anoxic/Oxic Membrane Bioreactors (MBR) were used simultaneously to investigate the effects of solids retention time (SRT) on organic and nitrogen removal in MBR for treating domestic wastewater. COD removal efficiencies in all reactors were consistently above 94% under steady state conditions. Complete conversion of NH4+-N to NO3--N was readily achieved over a feed NH4+-N concentration range of 30 to 50 mg/L. It was also observed that SRT did not significantly affect the nitrification in the MBR systems investigated. The average denitrification efficiencies for the 3, 5, 10 and 20 days SRT operations were 43.9, 32.6, 47.5 and 66.5%, respectively. In general, the average effluent nitrogen concentrations, which were mainly nitrate, were about 22.2, 27.6, 21.7 and 13.9 mg/L for the 3, 5, 10 and 20 days SRT systems, respectively. The rate of membrane fouling at 3 days SRT operation was more rapid than that observed at 5 days SRT. No fouling was noted in the 10 days and 20 days SRT systems during the entire period of study.


2011 ◽  
Vol 14 (1) ◽  
pp. 56-64
Author(s):  
Uan Khac Do ◽  
Banu J. Rajesh ◽  
Ick T. Yeom

Sludge production in the membrane bioreactor treating municipal wastewater can be estimated from the kinetic equation which describes a relationship between sludge concentration and substrate, decay coefficient, sludge retention time and hydraulic retention time. Based on the experimental data and using the mathematical approximate method, the theoretical yield factor (Y) and the decay coefficient (kd) were found to be 0.33 mg VSS/mg COD and 0.04 1/day, respectively. Sludge production in the system can be estimated from the obtained kinetic equation. The calculated values were fluctuated around the measured ones. This result proved the potential application of the obtained equation for estimation of the biomass concentration and kinetic parameters in the wastewater treatment systems using membrane bioreactor technology.


Sign in / Sign up

Export Citation Format

Share Document