scholarly journals Removal of Emerging Contaminants from Wastewater Streams Using Membrane Bioreactors: A Review

Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 60
Author(s):  
Arijit Sengupta ◽  
Mahmood Jebur ◽  
Mohanad Kamaz ◽  
S. Ranil Wickramasinghe
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Emerging Contaminants ◽  
Treatment Process ◽  
Membrane Separation ◽  
Membrane Surface ◽  
Membrane Bioreactors ◽  
Size Exclusion ◽  
Wastewater Treatment Process ◽  
Activated Sludge Processes

Water is a very valuable natural resource. As the demand for water increases the presence of emerging contaminants in wastewater has become a growing concern. This is particularly true when one considers direct reuse of wastewater. Obtaining sufficient removal of emerging contaminants will require determining the level of removal for the various unit operations in the wastewater treatment process. Membrane bioreactors are attractive as they combine an activated sludge process with a membrane separation step. They are frequently used in a wastewater treatment process and can operate at higher solid loadings than conventional activated sludge processes. Determining the level of removal of emerging contaminants in the membrane bioreactor step is, therefore, of great interest. Removal of emerging contaminants could be by adsorption onto the biomass or membrane surface, biotransformation, size exclusion by the membrane, or volatilization. Given the fact that most emerging contaminants are low molecule weight non-volatile compounds, the latter two methods of removal are usually unimportant. However, biotransformation and adsorption onto the biomass are important mechanisms of removal. It will be important to determine if the microorganisms present at given treatment facility are able to remove ECs present in the wastewater.

Floc size distribution and bacterial activities in membrane separation activated sludge processes for small-scale wastewater treatment/reclamation

1997 ◽  
Vol 35 (6) ◽  
pp. 37-44 ◽  
Author(s):  
Boran Zhang ◽  
Kazuo Yamamoto ◽  
Shinichiro Ohgaki ◽  
Naoyuki Kamiko
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Membrane Separation ◽  
Small Scale ◽  
Nitrification Rate ◽  
Floc Size ◽  
Denitrification Activity ◽  
Concentration Changes ◽  
Activated Sludge Processes

Activated sludges taken from full-scale membrane separation processes, building wastewater reuse system (400m3/d), and two nightsoil treatment plants (50m3/d) as well as laboratory scale membrane separation bioreactor (0.062m3/d) were analyzed to characterize membrane separation activated sludge processes (MSAS). They were also compared with conventional activated sludges(CAS) taken from municipal wastewater treatment plants. Specific nitrification activity in MSAS processes averaged at 2.28gNH4-N/kgMLSS.h were higher than that in CAS processes averaged at 0.96gNH4-N/kgMLSS.h. The denitrification activity in both processes were in the range of 0.62-3.2gNO3-N/kgMLSS.h without organic addition and in the range of 4.25-6.4gNO3-N/kgMLSS.h with organic addition. The organic removal activity in nightsoil treatment process averaged at 123gCOD/kgMLSS.h which was significantly higher than others. Floc size distributions were measured by particle sedimentation technique and image analysis technique. Flocs in MSAS processes changed their sizes with MLSS concentration changes and were concentrated at small sizes at low MLSS concentration, mostly less than 60 μm. On the contrary, floc sizes in CAS processes have not much changed with MLSS concentration changes and they were distributed in large range. In addition, the effects of floc size on specific nitrification rate, denitrification rate with and without organic carbon addition were investigated. Specific nitrification rate was decreased as floc size increased. However, little effect of floc size on denitrification activity was observed.

scholarly journals Unravelling diversity and metabolic potential of microbial consortia at each stage of leather sewage treatment

RSC Advances ◽  
2017 ◽  
Vol 7 (66) ◽  
pp. 41727-41737 ◽  
Author(s):  
Hebin Liang ◽  
Dongdong Ye ◽  
Lixin Luo
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Treatment Process ◽  
Sewage Treatment ◽  
Microbial Consortia ◽  
Biological Wastewater Treatment ◽  
Metabolic Potential ◽  
Ecological Functions ◽  
Wastewater Treatment Process ◽  
System P

Activated sludge is essential for the biological wastewater treatment process and the identification of active microbes enlarges awareness of their ecological functions in this system.

Simultaneous activated sludge wastewater treatment and odour control

2001 ◽  
Vol 44 (9) ◽  
pp. 189-196 ◽  
Author(s):  
P. Hardy ◽  
J.E. Burgess ◽  
S. Morton ◽  
R.M. Stuetz
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Treatment Process ◽  
Treatment Plant ◽  
Process Performance ◽  
Wastewater Treatment Process ◽  
Wet Scrubbing ◽  
Odour Control ◽  
Removal Efficiencies ◽  
Performance Results

Lab-scale tests were used to determine the amount of H2S that can be treated using a range of different activated sludges. Static vessels were used to study the effects of different H2S concentrations (5, 25, 50 and 75 ppm). The data indicated that odour control may be carried out using certain types of sludge, but sludge type, e.g. carbonaceous, nitrifying, with or without coagulant, affects removal efficiency. The presence of the biomass resulted in greater H2S removal than the use of wet scrubbing and the adverse effects on mixed liquor were negligible. A pilot plant was used to study the removal efficiencies of activated sludge diffusion using a typical wastewater treatment plant H2S concentration and investigated the effects that the diffusion of H2S had on the process performance. Results indicated that the levels of H2S produced by other unit processes on a wastewater treatment site (approximately 5 ppm) can be treated using activated sludge diffusion without compromising the performance of the wastewater treatment process. The only effects on the activated sludge plant observed were: (1) nitrification was interrupted briefly as H2S diffusion commenced and (2) the species' diversity in the sludge decreased.

Replacement of Secondary Clarification by Membrane Separation—Results with Tubular, Plate and Hollow Fibre Modules

1999 ◽  
Vol 40 (4-5) ◽  
pp. 311-320 ◽  
Author(s):  
Berthold Günder ◽  
Karlheinz Krauth
Keyword(s):  
Activated Sludge ◽  
Suspended Solids ◽  
Membrane Separation ◽  
Membrane Surface ◽  
Hollow Fibre ◽  
Stable Operation ◽  
Membrane Systems ◽  
Process Technology ◽  
Mixed Liquor ◽  
Activated Sludge Processes

Membrane separation systems can replace the final clarification step to separate mixed liquor suspended solids (MLSS) in the activated sludge processes. Mixed liquor suspended solids concentrations as high as 20 g/l can be obtained compared with the typical 3-4 g/l for conventional activated sludge/secondary clarifier systems. This leads to much smaller reactor volumes. In addition, excellent, solids free effluent qualities can be achieved with this process technology. This paper reports about the parallel investigation of three membrane systems installed within or outside bioreactors of 7 to 9 m3 volume and flow rates from 1 to 3 m3/h. The different membrane modules were investigated: plate module (80 m2 membrane surface), hollow fibre module (80 m2) and tubular module (45 m2). At MLSS concentrations up to 25 g/l and water temperatures from 10 to 25°C a stable operation of the membrane systems was achieved for a period of more than one year. The energy consumption was approximately 1.5 kWh/m3 for the plate and hollow fibre and 3.0 kWh/m3 for the tubular module system.

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