Application of the ceramic membrane with hydrophobic skin layer to separation of activated sludge

1997 ◽  
Vol 35 (8) ◽  
pp. 137-144 ◽  
Author(s):  
Tsuyoshi Nomura ◽  
Takao Fujii ◽  
Motoyuki Suzuki
Keyword(s):  
Activated Sludge ◽  
Pore Size ◽  
Ceramic Membrane ◽  
Membrane Separation ◽  
Porous Ceramic ◽  
Porous Membrane ◽  
Skin Layer ◽  
Gas Permeation ◽  
Wide Range ◽  
Cake Layer

Porous membrane of poly(tetrafluoroethylene) (PTFE) was formed on the surface of porous ceramic tubes by means of heat treatment of the PTFE particles deposit layer prepared by filtering PTFE microparticles emulsified in aqueous phase. By means of inert gas permeation, pore size was determined and compared with scanning electron micrograph observation. Also rejection measurement of aqueous dextran solutions of wide range of molecular weights showed consistent results regarding the pore size. Since the membrane prepared by this method is stable and has unique features derived from PTFE, it is expected that the membrane has interesting applications in the field of water treatment. Membrane separation of activated sludge by this composite membrane and original ceramics membrane showed that the PTFE membrane gives better detachability of the cake layer formed on the membrane. This might be due to the hydrophobic nature of the PTFE skin layer.

scholarly journals Gas Permeation Characteristics across Nano-Porous Inorganic Membranes

1970 ◽  
Vol 5 (2) ◽  
Author(s):  
M.R Othman, H. Mukhtar ◽  
A.L. Ahmad
Keyword(s):  
Pore Size ◽  
Membrane Surface ◽  
Porous Ceramic ◽  
Knudsen Diffusion ◽  
Gas Permeation ◽  
Physical Characteristics ◽  
Inorganic Membrane ◽  
Molecular Characteristics ◽  
Inorganic Membranes ◽  
Operational Parameters

An overview of parameters affecting gas permeation in inorganic membranes is presented. These factors include membrane physical characteristics, operational parameters and gas molecular characteristics. The membrane physical characteristics include membrane materials and surface area, porosity, pore size and pore size distribution and membrane morphology. The operational parameters include feed flow rate and concentration, stage cut, temperature and pressure. The gas molecular characteristics include gas molecular weight, diameter, critical temperature, critical pressure, Lennard-Jones parameters and diffusion volumes. The current techniques of material characterization may require complementary method in describing microscopic heterogeneity of the porous ceramic media. The method to be incorporated in the future will be to apply a stochastic model and/or fractal dimension. Keywords: Inorganic membrane, surface adsorption, Knudsen diffusion, Micro-porous membrane, permeation, gas separation.

scholarly journals Modeling of ethylbenzene dehydrogenation in catalytic membrane reactor with porous membrane

2014 ◽  
Vol 2 (1) ◽  
pp. 1-9 ◽  
Author(s):  
E.V. Shelepova ◽  
A.A. Vedyagin ◽  
I.V. Mishakov ◽  
A.S. Noskov
Keyword(s):  
Mathematical Model ◽  
Membrane Reactor ◽  
Ceramic Membrane ◽  
Porous Ceramic ◽  
Porous Membrane ◽  
Membrane Reactors ◽  
Catalytic Membrane ◽  
Catalytic Membrane Reactor ◽  
Membrane Pore ◽  
Ethylbenzene Dehydrogenation

AbstractThe modeling of ethylbenzene dehydrogenation in a catalytic membrane reactor has been carried out for porous membrane by means of two-dimensional, non-isothermal stationary mathematical model. A mathematical model of the catalytic membrane reactor was applied, in order to study the effects of transport properties of the porous membrane on process performance. The performed modeling of the heat and mass transfer processes within the porous membrane, allowed us to estimate the efficiency of its use in membrane reactors, in comparison with a dense membrane (with additional oxidation of the hydrogen in shell side). The use of a porous ceramic membrane was found to cause an increase of the ethylbenzene conversion at 600°C, up to 93 %, while the conversion in the case of conventional reactor was 67%. In this work, we defined the key parameter values of porous membrane (pore diameter and thickness) for ethylbenzene dehydrogenation in catalytic membrane reactor, at which the highest conversion of ethylbenzene and styrene selectivity can be reached.

Performance and fouling characteristics of different pore-sized submerged ceramic membrane bioreactors (SCMBR)

2009 ◽  
Vol 59 (11) ◽  
pp. 2213-2218 ◽  
Author(s):  
Le Jin ◽  
How Yong Ng ◽  
Say Leong Ong
Keyword(s):  
Pore Size ◽  
Ceramic Membrane ◽  
Membrane Separation ◽  
Rejection Rate ◽  
Ceramic Membranes ◽  
Ammonia Nitrogen ◽  
Membrane Bioreactors ◽  
Membrane Pore ◽  
Toc Removal ◽  
Membrane Pore Size

The membrane bioreactor (MBR), a combination of activated sludge process and the membrane separation system, has been widely used in wastewater treatment. However, 90% of MBR reported were employing polymeric membranes. The usage of ceramic membranes in MBR is quite rare. Four submerged ceramic membrane bioreactors (SCMBRs) with different membrane pore size were used in this study to treat sewage. The results showed that the desirable carbonaceous removal of 95% and ammonia nitrogen removal of 98% were obtained for all the SCMBRs. It was also showed that the ceramic membranes were able to reject some portions of the protein and carbohydrate, whereby the carbohydrate rejection rate was much higher than that of protein. Membrane pore size did not significantly affect the COD and TOC removal efficiencies, the composition of EPS and SMP or the membrane rejection rate, although slight differences were observed. The SCMBR with the biggest membrane pore size fouled fastest, and membrane pore size was a main contributor for the different fouling potential observed.

scholarly journals A Morphological Study of Poly (Vinylidene Fluoride) Pvdf Membranes: In Perspective of Membrane Pervaporation Process

2015 ◽  
Vol 14 (2) ◽  
pp. 38
Author(s):  
Adil Hatem Rashid ◽  
M. D. Irfan Hatem ◽  
Muhammad Syarhabil Ahmad ◽  
Mohd. Hafiz Dzarfan Othman
Keyword(s):  
Contact Angle ◽  
Pore Size ◽  
Polyvinylidene Fluoride ◽  
Vinylidene Fluoride ◽  
Membrane Separation ◽  
Polymer Concentration ◽  
Inversion Method ◽  
Separation Processes ◽  
Pvdf Membrane ◽  
Wide Range

Membrane separation plays an important role in chemical industry (Prabhat et al. 2011). Pervaporation is one of the most promising membrane separation processes which is used in a wide range of applications such as separation of organic mixtures and dehydration of solvents. This study investigated the effect of polymer concentration on the morphology of pervaporation membrane, where polyvinylidene fluoride (PVDF) was chosen as the base polymeric material while phase inversion method was employed as a technique to prepare an asymmetric PVDF membrane. The polymer concentration in dope solution was varied from 16 to 20wt% and the prepared membranes were characterized in terms of its structure, porosity, contact angle, and pore size. Five PVDF membrane samples were prepared (without any post-treatment) with polymer concentration of 16, 17, 18, 19, and 20wt% respectively. Depending on permeating component, two main areas of pervaporation processes can be identified: hydrophobic and hydrophilic and consequently two types of membranes could be observed: hydrophobic and hydrophilic membranes. From the results, it was found that the increase in polymer concentration has produced membranes with low pore size and porosity and as a result, high contact angle (low hydrophilicity).The highest contact angle of 83º was found for membrane with highest polymer concentration of 20wt% with the lowest pore size and porosity of (0.4156µm and 65%) respectively. The lowest contact angle of 76º was found for membrane with the lowest polymer concentration of 16wt% with the highest pore size and porosity (0.8671µm and78%) respectively.

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 Xylanolytic Bacillus species for xylooligosaccharides production: a critical review

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Rozina Rashid ◽  
Muhammad Sohail
Keyword(s):  
Large Scale ◽  
Extracellular Enzymes ◽  
Membrane Separation ◽  
Well Being ◽  
Bacillus Species ◽  
Scale Production ◽  
Food Ingredients ◽  
Large Scale Production ◽  
Wide Range ◽  
Biological Impacts

AbstractThe capacity of different Bacillus species to produce large amounts of extracellular enzymes and ability to ferment various substrates at a wide range of pH and temperature has placed them among the most promising hosts for the industrial production of many improved and novel products. The global interest in prebiotics, for example, xylooligosaccharides (XOs) is ever increasing, rousing the quest for various forms with expanded productivity. This article provides an overview of xylanase producing bacilli, with more emphasis on their capacity to be used in the production of the XOs, followed by the purification strategies, characteristics and application of XOs from bacilli. The large-scale production of XOs is carried out from a number of xylan-rich lignocellulosic materials by chemical or enzymatic hydrolysis followed by purification through chromatography, vacuum evaporation, solvent extraction or membrane separation methods. Utilization of XOs in the production of functional products as food ingredients brings well-being to individuals by improving defense system and eliminating pathogens. In addition to the effects related to health, a variety of other biological impacts have also been discussed.

scholarly journals Effect of Pre-Oxidation on Coagulation/Ceramic Membrane Treatment of Yangtze River Water

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 369
Author(s):  
Shengji Xia ◽  
Xinran Zhang ◽  
Yuanchen Zhao ◽  
Fibor J. Tan ◽  
Pan Li ◽  
...  
Keyword(s):  
Water Treatment ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Ceramic Membrane ◽  
Membrane Separation ◽  
Membrane System ◽  
Coagulation System ◽  
Fouling Control ◽  
Filtration System ◽  
Membrane Treatment

The membrane separation process is being widely used in water treatment. It is very important to control membrane fouling in the process of water treatment. This study was conducted to evaluate the efficiency of a pre-oxidation-coagulation flat ceramic membrane filtration process using different oxidant types and dosages in water treatment and membrane fouling control. The results showed that under suitable concentration conditions, the effect on membrane fouling control of a NaClO pre-oxidation combined with a coagulation/ceramic membrane system was better than that of an O3 system. The oxidation process changed the structure of pollutants, reduced the pollution load and enhanced the coagulation process in a pre-oxidation-coagulation system as well. The influence of the oxidant on the filtration system was related to its oxidizability and other characteristics. NaClO and O3 performed more efficiently than KMnO4. NaClO was more conducive to the removal of DOC, and O3 was more conducive to the removal of UV254.

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