Mathematical Modeling of Aerobic Membrane Bioreactor (MBR) Using Hybrid Activated Sludge Model No. 3 (ASM3)

2010 ◽  
Vol 113-116 ◽  
pp. 1424-1428
Author(s):  
Yu Tian ◽  
Lin Chen ◽  
Xin Ying Su ◽  
Chu Qing Cao

Recent trend for membrane bioreactor (MBR) operation was to apply a low sludge retention time (SRT) to decrease the fouling propensity and simplify the overall maintenance. However, the correct control and operation of MBRs under low SRT conditions were not well-established. In this study, modeling of MBR system for municipal wastewater treatment was evaluated using hybrid Activated Sludge Models 3 (ASM3), which helped in determining the control and operating strategies. The experiment-based, manual trial-and-error approach used to calibrate the hybrid ASM3 was verified to be useful for MBR modeling at 30 d sludge retention time (SRT). Furthermore, the consistency relationships among carbon oxygen demanded (COD), soluble microbial products (SMP) and mixed liquor suspended solids (MLSS) were established in the process of modeling, implying that the accurate simulation of MLSS were the prerequisites for the COD and SMP prediction.

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 421
Author(s):  
Dimitra C. Banti ◽  
Michail Tsangas ◽  
Petros Samaras ◽  
Antonis Zorpas

Membrane bioreactor (MBR) systems are connected to several advantages compared to the conventional activated sludge (CAS) units. This work aims to the examination of the life cycle environmental impact of an MBR against a CAS unit when treating municipal wastewater with similar influent loading (BOD = 400 mg/L) and giving similar high-quality effluent (BOD < 5 mg/L). The MBR unit contained a denitrification, an aeration and a membrane tank, whereas the CAS unit included an equalization, a denitrification, a nitrification, a sedimentation, a mixing, a flocculation tank and a drum filter. Several impact categories factors were calculated by implementing the Life Cycle Assessment (LCA) methodology, including acidification potential, eutrophication potential, global warming potential (GWP), ozone depletion potential and photochemical ozone creation potential of the plants throughout their life cycle. Real data from two wastewater treatment plants were used. The research focused on two parameters which constitute the main differences between the two treatment plants: The excess sludge removal life cycle contribution—where GWPMBR = 0.50 kg CO2-eq*FU−1 and GWPCAS = 2.67 kg CO2-eq*FU−1 without sludge removal—and the wastewater treatment plant life cycle contribution—where GWPMBR = 0.002 kg CO2-eq*FU−1 and GWPCAS = 0.14 kg CO2-eq*FU−1 without land area contribution. Finally, in all the examined cases the environmental superiority of the MBR process was found.


2014 ◽  
Vol 8 (1) ◽  
pp. 25-29
Author(s):  
Alaa K. Mohammed ◽  
Qusay Fathel ◽  
Safaa A. Ali

A membrane bioreactor (MBR) is one of the modifications to the conventional activated sludge process, since it is the combination of a membrane module and a bioreactor. In the present study, 100 liters lab-scale aerobic MBR was seeded with 1.5 Liter activated sludge and municipal wastewater from AL-Rustumiya municipal wastewater treatment station, two hollow fibers sample (MI,MII) manufactured in the University of Technology/ Chemical Engineering Department, were used as biomembranes. Trans membrane pressure TMP was studied and it was found that the optimum value of TMP was 10 cm Hg vacuum which gave optimum effluent flux 400 ml/hr for MI and 350 ml/hr for MII. The experimental work involves the effect of temperature 25, 35, 45°C on the performance of the MBR fibers sample (MI, MII) and its effect on biomass growth and removal efficiency of the COD, BOD. Both samples show good performance in 25°C.


2018 ◽  
Vol 53 ◽  
pp. 04039
Author(s):  
Xinyue Jiang ◽  
Bin Xu

The previously assumed “inert” organics measured by respirometric method has been reported to be hydrolysable under long sludge retention time (SRT) configuration such as membrane bioreactor(MBR). The sludge production under long SRT has also shown to be lower than the standard activated sludge model (ASM) prediction. The hydrolysis of “inert” organics can provide the extra carbon source for denitrification. The current modeling approach has not yet included this aspect. In this study, a modified ASM3 was developed to account for the hydrolysis of “inert” organics and subsequent effect on the denitrification process under long SRT.


2017 ◽  
Vol 77 (3) ◽  
pp. 714-720 ◽  
Author(s):  
J. C. Leyva-Díaz ◽  
A. Rodríguez-Sánchez ◽  
J. González-López ◽  
J. M. Poyatos

Abstract A membrane bioreactor (MBR) and a hybrid moving bed biofilm reactor-membrane bioreactor (hybrid MBBR-MBR) for municipal wastewater treatment were studied to determine the effect of salinity on nitrogen removal and autotrophic kinetics. The biological systems were analyzed during the start-up phase with a hydraulic retention time (HRT) of 6 h, total biomass concentration of 2,500 mg L−1 in the steady state, and electric conductivities of 1.05 mS cm−1 for MBR and hybrid MBBR-MBR working under regular salinity and conductivity variations of 1.2–6.5 mS cm−1 for MBR and hybrid MBBR-MBR operating at variable salinity. The variable salinity affected the autotrophic biomass, which caused a reduction of the nitrogen degradation rate, an increase of time to remove ammonium from municipal wastewater and longer duration of the start-up phase for the MBR and hybrid MBBR-MBR.


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.


2008 ◽  
Vol 57 (3) ◽  
pp. 319-322 ◽  
Author(s):  
A. Pollice ◽  
G. Laera ◽  
D. Saturno ◽  
C. Giordano ◽  
R. Sandulli

Membrane bioreactors allow for higher sludge concentrations and improved degradation efficiencies with respect to conventional activated sludge. However, in the current practice these systems are often operated under sub-optimal conditions, since so far no precise indications have yet been issued on the optimal operating conditions of MBR for municipal wastewater treatment. This paper reports some results of four years of operation of a bench scale membrane bioreactor where steady state conditions were investigated under different sludge retention times. The whole experimental campaign was oriented towards the investigation of optimal process conditions in terms of COD removal and nitrification, biomass activity and growth, and sludge characteristics. The membrane bioreactor treated real municipal sewage, and four different sludge ages were tested (20, 40, 60, and 80 days) and compared with previous data on complete sludge retention. The results showed that the the biology of the system, as assessed by the oxygen uptake rate, is less affected than the sludge physical parameters. In particular, although the growth yield was observed to dramatically drop for SRT higher than 80 days, the biological activity was maintained under all the tested conditions. These considerations suggest that high SRT are convenient in terms of limited excess sludge production without losses of the treatment capacity. Physical characteristics such as the viscosity and the filterability appear to be negatively affected by prolonged sludge retention times, but their values remain within the ranges normally reported for conventional activated sludge.


2010 ◽  
Vol 113-116 ◽  
pp. 2057-2061 ◽  
Author(s):  
Zhan Ping Cao ◽  
Jing Li Zhang ◽  
Hong Wei Zhang

In the membrane bioreactor (MBR) treating municipal wastewater, the effect of sludge retention time (SRT) on the contents of the extracellular polymeric substances (EPS), tightly bound EPS (TB) and loosely bound EPS (LB) and the ratios of protein and polysaccharide in TB and LB was studied. With the extension of SRT the EPS increased and the ratios of protein and polysaccharide in TB and LB changed. The above changes influenced the charge distribution of bacterial surface, increased the proportion of hydrophilicity and hydrophobicity on the bacterial surface, changed the bacteria from the instable (R-type) to the stable (S-type), decreased the Zeta potential and increased the values of sludge volume index (SVI). The correlation analysis for the main parameters of fouling resistance was performed by SPSS software, and it was found that the correlation coefficient (rp) was -0.818 for Zeta potential, 0.853 for the content of suspended solids in supernatant and 0.832 for relative hydrophobicity, respectively. SRT of the MBR should be controlled below 120 times of the minimum generation-time of dominant bacteria considering the membrane fouling and sludge characteristics.


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