Activated sludge diffusion for efficient simultaneous treatment of municipal wastewater and odor in a membrane bioreactor

2021 ◽  
Vol 415 ◽  
pp. 128765
Author(s):  
Fuqiang Fan ◽  
Ronghua Xu ◽  
Depeng Wang ◽  
Junshi Tao ◽  
Yifeng Zhang ◽  
...  
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.


1997 ◽  
Vol 35 (10) ◽  
pp. 147-153 ◽  
Author(s):  
C. Bornhardt ◽  
J. E. Drewes ◽  
M. Jekel

The effectiveness of different treatments with powdered activated carbons (PAC) to reduce the AOX-levels in municipal wastewater was investigated in a bench-scale activated sludge (AS) treatment plant. The PAC was added either directly to the aerated basin (simultaneous PAC-treatment), or to a partial stream of clarified effluent, which was treated with PAC in an agitated tank and recirculated to the aerated basin (subsequent PAC-treatment with recirculation). The standard advanced biological treatment reduced the AOX-content by 24%. In the pilot-plant, three types of powdered activated carbons were tested for a simultaneous treatment. The treatment with 100 mg/l PICA PCO Super produced an additional reduction of AOX by 20%, whereas a dosage of 50 mg/l NORIT W-20 showed no enhancement effect, and W-35 led to an additional AOX-removal of about 9%. Also, an improved removal of DOC, NH4-N and PO4-P was observed. In all cases, the PAC addition caused a significantly improved settling of the AS, reducing the sludge-volume-index, and increasing the content of volatile solids of the PAC-sludge. In general, no evidence of a synergistic effect of the PAC addition to activated sludge, nor bioregeneration of the activated carbon, could be observed. This suggests, that the observed effects probably are caused only by simple adsorption.


2013 ◽  
Vol 67 (4) ◽  
pp. 789-796 ◽  
Author(s):  
Mathieu Spérandio ◽  
Marc-André Labelle ◽  
Abdellah Ramdani ◽  
Alain Gadbois ◽  
Etienne Paul ◽  
...  

Activated sludge models have assumed that a portion of organic solids in municipal wastewater influent is unbiodegradable. Also, it is assumed that solids from biomass decay cannot be degraded further. The paper evaluates these assumptions based on data from systems operating at higher than typical sludge retention times (SRTs), including membrane bioreactor systems with total solids retention (no intentional sludge wastage). Data from over 30 references and with SRTs of up to 400 d were analysed. A modified model that considers the possible degradation of the two components is proposed. First order degradation rates of approximately 0.007 d–1 for both components appear to improve sludge production estimates. Factors possibly influencing these degradation rates such as wastewater characteristics and bioavailability are discussed.


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.


1996 ◽  
Vol 34 (9) ◽  
pp. 197-203 ◽  
Author(s):  
H. Winnen ◽  
M. T. Suidan ◽  
P. V. Scarpino ◽  
B. Wrenn ◽  
N. Cicek ◽  
...  

The activated sludge process has been used extensively to treat municipal wastewater. The membrane bioreactor (MBR) process is a modification of the conventional activated sludge process where the clarifier is replaced with a membrane system for separation between the mixed liquor and the effluent. This paper presents the biological and physical performance data of a pilot-scale membrane bioreactor system, fed with a synthetic wastewater. At steady state, particularly high effluent quality was obtained and maintained for an extended period of time. Heterotrophic plate counting showed that the membrane retains heterotrophic microorganisms. Bacteriophage MS-2 was used to determine the retention of viruses. The membrane proved to retain the MS-2 virus.


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.


1996 ◽  
Vol 34 (1-2) ◽  
pp. 129-136 ◽  
Author(s):  
Fan Xiao-Jun ◽  
Vincent Urbain ◽  
Yi Qian ◽  
Jacques Manem

The overall performance of the Membrane Bioreactor (MBR) process for municipal wastewater treatment was studied to determine the characteristics of activated sludge under different Sludge Retention Times (SRT) and Hydraulic Retention Times (HRT). The experiment lasted over a period of 300 days, which included 4 runs. The effluent quality of the MBR process in terms of COD and suspended solids, was excellent under all conditions tested. Specific nitrification rates of the activated sludge were measured at steady state in each run. Similar maximum nitrification rate values were obtained through batch experiments with either only NH4Cl or raw wastewater as substrate. Mass balances of the process in terms of COD, nitrogen and inorganic suspended solids were made, and it was found that 28%, 42%, and 48% of influent COD were converted into activated sludge at SRTs of 20, 10, and 5 days, respectively. The COD/VSS ratio of the activated sludge seems to be dependent on mass loading rate. The estimated true yield and decay rate coefficients of the activated sludge were 0.61 kgCOD/kgCOD and 0.050 d−1, respectively. In the completely aerobic system, nitrogen balances were always close to 100%.


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