Cross-flow microfiltration with high frequency reverse flow

2000 ◽  
Vol 41 (10-11) ◽  
pp. 337-343 ◽  
Author(s):  
M. Héran ◽  
S. Elmaleh
Keyword(s):  
Flow Velocity ◽  
High Frequency ◽  
Ceramic Membrane ◽  
Reverse Flow ◽  
Cross Flow ◽  
The Other ◽  
Treated Wastewater ◽  
Permeate Flux ◽  
Cross Flow Velocity ◽  
Bentonite Suspension

High frequency reverse filtration was evaluated while microfiltering a bentonite suspension, biologically treated wastewater and an activated sludge suspension through a 0.2 μm tubular ceramic membrane. Better results were obtained with a conventional internal layer filtration element than with an external skin membrane. However the technique was efficient in enhancing the permeate flux solely with the bentonite suspension. In the other cases, the flux was the same as in conventional cross-flow operation. Such a failure cannot be exclusively attributed to chemical interactions with the membrane since the permeate flux increased linearly with cross-flow velocity for all suspensions in conventional operation. Much research is then required to establish the technique applicability.

scholarly journals Operating Conditions Optimization via the Taguchi Method to Remove Colloidal Substances from Recycled Paper and Cardboard Production Wastewater

Membranes ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 170 ◽  
Author(s):  
Mayko Rannany S. Sousa ◽  
Jaime Lora-García ◽  
María-Fernanda López-Pérez ◽  
Asunción Santafé-Moros ◽  
José M. Gozálvez-Zafrilla
Keyword(s):  
Taguchi Method ◽  
Flow Velocity ◽  
Cross Flow ◽  
Rejection Rate ◽  
Transmembrane Pressure ◽  
Optimal Conditions ◽  
Permeate Flux ◽  
Utility Concept ◽  
Cross Flow Velocity ◽  
Response Variables

Optimization of the ultrafiltration (UF) process to remove colloidal substances from a paper mill’s treated effluent was investigated in this study. The effects of four operating parameters in a UF system (transmembrane pressure (TMP), cross-flow velocity (CFV), temperature and molecular weight cut-off (MWCO)) on the average permeate flux (Jv), organic matter chemical oxygen demand (COD) rejection rate and the cumulative flux decline (SFD), was investigated by robust experimental design using the Taguchi method. Analysis of variance (ANOVA) for an L9 orthogonal array were used to determine the significance of the individual factors, that is to say, to determine which factor has more and which less influence over the UF response variables. Analysis of the percentage contribution (P%) indicated that the TMP and MWCO have the greatest contribution to the average permeate flux and SFD. In the case of the COD rejection rate, the results showed that MWCO has the highest contribution followed by CFV. The Taguchi method and the utility concept were employed to optimize the multiple response variables. The optimal conditions were found to be 2.0 bar of transmembrane pressure, 1.041 m/s of the cross-flow velocity, 15 °C of the temperature, and 100 kDa MWCO. The validation experiments under the optimal conditions achieved Jv, COD rejection rate and SFD results of 81.15 L·m−2·h−1, 43.90% and 6.01, respectively. Additionally, SST and turbidity decreased by about 99% and 99.5%, respectively, and reduction in particle size from around 458–1281 nm to 12.71–24.36 nm was achieved. The field-emission scanning electron microscopy images under optimal conditions showed that membrane fouling takes place at the highest rate in the first 30 min of UF. The results demonstrate the validity of the approach of using the Taguchi method and utility concept to obtain the optimal membrane conditions for the wastewater treatment using a reduced number of experiments.

scholarly journals Fouling Behaviour During Cross Flow Ultrafiltration of Cassava Starch Hydrolysate Using Polyacrylonitrile Membrane

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
I. N. Widiasa ◽  
I. G. Wenten
Keyword(s):  
Flow Velocity ◽  
Cross Flow ◽  
Cassava Starch ◽  
Alkaline Condition ◽  
Transmembrane Pressure ◽  
Permeate Flux ◽  
Promising Alternative ◽  
Glucose Syrup ◽  
Cross Flow Velocity ◽  
Starch Hydrolysate

Ultrafiltration (UF) is considered as a promising alternative to the traditional clarification techniques in the sugar industries. In this work, a hollow fiber UF membrane (polyacrylonitrile, MWCO 100 kDa) was used for clarification of cassava starch hydrolysate. The influence of various operating parameters, such as transmembrane pressure (TMP), cross flow velocity and pH hydrolysate on the membrane fouling was assessed. The results showed that TMP higher than 1.0 bar was not effective to improve flux. Increasing cross flow velocity was virtually effective to reduce permeate flux decline. The steady state flux, Jssincreased significantly when pH of the feed was adjusted to alkaline condition; however, this resulted in dark brown clarified glucose syrup. Operating at natural pH of 4.5, the membrane selectivity was close to 100%. Evaluation of hydraulic resistance indicated that concentration polarization and pore blocking were beyond approximately 50 and 40% of the total filtration resistance, respectively. Moreover, scanning electron microscopy showed that extensive fouling layer was deposited on the membrane surface. Finally, the developed cleaning procedure could restore membrane performance approximately 45% of its initial performance.

Parametric Study of Ultrafiltration

2009 ◽  
Author(s):  
Nina Zhou ◽  
A. G. Agwu Nnanna
Keyword(s):  
Flow Velocity ◽  
Suspended Solids ◽  
Cross Flow ◽  
Transmembrane Pressure ◽  
High Flux ◽  
Permeate Flux ◽  
Membrane Performance ◽  
Cross Flow Velocity ◽  
High Concentrations ◽  
Cleaning Methods

The performance of cross flow hollow fiber ultrafiltration (UF) membrane with molecular weight cut off (MWCO) 100 kDaltons was studied in order to effectively remove suspended solids in wastewater. Experiments were carried out to investigate the influence of the several factors such as cross flow velocity, transmembrane pressure (TMP), water temperature, and concentration of suspended solids on the membrane performance. Several cleaning methods were applied to remove the fouling. The experimental results showed that increasing TMP, temperature and cross flow velocity all resulted in increasing permeate flux. It is observed that high TMP aggravated the fouling while high cross flow velocity alleviated the fouling. High concentrations of suspended solids led to the reduction of permeate flux. It is also found that both combination of chemical, back- and forward-washing as well as soaking cleaning methods effectively removed fouling and achieved high flux recovery. The suspended solids were effectively removed by our UF system, and the water quality is significantly improved after ultrafiltration.

scholarly journals DETERMINATION OF FOULING MECHANISM IN ULTRAFILTRATION OF ELECTROPLATING WASTEWATER

2018 ◽  
Vol 80 (3-2) ◽  
Author(s):  
Danu Ariono ◽  
Anita Kusuma Wardani ◽  
Putu Teta Prihartini Aryanti ◽  
Ahmad Nurul Hakim ◽  
I Gede Wenten
Keyword(s):  
Flow Velocity ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Cross Flow ◽  
Permeate Flux ◽  
High Concentration ◽  
Filtration Time ◽  
Electroplating Wastewater ◽  
Fouling Mechanism ◽  
Cross Flow Velocity

Wastewater from electroplating industries is usually contaminated with high concentration of hazardous materials, such as nickel, copper, and chromium. Therefore, the electroplating wastewater is one of the environmental problems that require a novel solution to reduce risks for human and environment. Ultrafiltration is a promising technology to overcome this problem due to its ability to reject all suspended solids. However, membrane fouling still becomes a major obstacle in ultrafiltration processes. Fouling reduces the permeate flux and increases membrane operational costs due to membrane cleaning. In this work, fouling mechanism that occurred in polyacrylonitrile based ultrafiltration for electroplating wastewater treatment was investigated. The effects of trans-membrane pressure (TMP) and cross flow velocity on fouling mechanism were also studied. The results showed that in the first 20 minutes, intermediate blocking was occurred on the membrane surface, while cake formation was happened for the rest of filtration time. These results were applied for all TMP and cross flow velocity.

Removal of Amines from Wastewater Using Membrane Separation Processes

2014 ◽  
Vol 625 ◽  
pp. 639-643
Author(s):  
Ma Umaira Suhaddha Zainal Abidin ◽  
Hilmi Mukhtar ◽  
Maizatul Shima Shaharun
Keyword(s):  
Natural Gas ◽  
Flow Velocity ◽  
Membrane Separation ◽  
Cross Flow ◽  
Operating Pressure ◽  
Permeate Flux ◽  
Feed Concentration ◽  
Separation Processes ◽  
Increase With Increase ◽  
Cross Flow Velocity

Natural gas is one of the energy sources in the world. It consists of predominantly methane (CH4), ethane (C2H6), ethylene (C2H4), propane (C3H8) butane (C4H10), pentane (C5H12) and some impurities particularly hydrogen sulfide (H2S) and carbon dioxide (CO2) that need to be treated prior utilized. Amine solution such as diisopropanolamine (DIPA) is used to remove the CO2 and H2S in natural gas processing. However a small amount of amines losses in some unit operations causing amines discharged into the effluent wastewater. The objective of this study are to investigate the flux of water and permeate, and rejection of DIPA solution across reverse osmosis, nanofiltration and ultrafiltration membrane which known as AFC99, AFC40 and CA202 respectively. This paper studies the effect of cross-flow velocity on permeate flux and the effect of feed concentration on observed rejection of DIPA solution across AFC99, AFC40 and CA202 over the operating pressure. The results showed a significant role of cross-flow velocity on membrane performance from aspect flux obtained and phenomenon of concentration polarization that would increase the transport resistance of permeate flow. The highest flux can be achieved by high cross-flow velocity. While for rejection study, rejection of all membranes increase with increase of pressure yet decrease with concentration.

Effect of Fluidized Bed on Permeate Flux in Ceramic Membrane Cross-Flow Microfiltration

1995 ◽  
Vol 60 (12) ◽  
pp. 2074-2084
Author(s):  
Petr Mikulášek
Keyword(s):  
Fluidized Bed ◽  
Ceramic Membrane ◽  
Cross Flow ◽  
Experimental System ◽  
Experimental Results ◽  
Spherical Particles ◽  
Permeate Flux ◽  
Model Fluid ◽  
Optimum Porosity ◽  
Tubular Membranes

The microfiltration of a model fluid on an α-alumina microfiltration tubular membrane in the presence of a fluidized bed has been examined. Following the description of the basic characteristic of alumina tubular membranes, model dispersion and spherical particles used, some comments on the experimental system and experimental results for different microfiltration systems are presented. From the analysis of experimental results it may be concluded that the use of turbulence-promoting agents resulted in a significant increase of permeate flux through the membrane. It was found out that the optimum porosity of fluidized bed for which the maximum values of permeate flux were reached is approximately 0.8.

Significance of Lorentz Force and Thermoelectric on the Flow of 29 nm CuO–Water Nanofluid on an Upper Horizontal Surface of a Paraboloid of Revolution

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
I. L. Animasaun ◽  
B. Mahanthesh ◽  
A. O. Jagun ◽  
T. D. Bankole ◽  
R. Sivaraj ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Numerical Solutions ◽  
Volume Fraction ◽  
Cross Flow ◽  
Horizontal Surface ◽  
Integration Scheme ◽  
Flowing Fluid ◽  
Paraboloid Of Revolution ◽  
Hall Parameter ◽  
Cross Flow Velocity

Combination of electric and magnetic forces on charged molecules of flowing fluid in the presence of a significant electromagnetic fields on surfaces with a nonuniform thickness (as in the case of upper pointed surface of an aircraft and bonnet of a car which are examples of upper horizontal surfaces of a paraboloid of revolution—uhspr) is inevitable. In this study, the influence of imposed magnetic field and Hall effects on the flow of 29 nm CuO–water nanofluid over such object is presented. Suitable similarity variables were employed to nondimensionalize and parameterize the dimensional governing equation. The numerical solutions of the corresponding boundary value problem were obtained using Runge–Kutta fourth-order integration scheme along with shooting technique. The domain of cross-flow velocity can be highly suppressed when the magnitude of imposed magnetic strength and that of Hall parameter are large. A significant increase in the cross-flow velocity gradient near an upper horizontal surface of the paraboloid of revolution is guaranteed with an increase in the Hall parameter. Enhancement of temperature distribution across the flow is apparent due to an increase in the volume fraction.

scholarly journals Biofouling Mitigation Approaches during Water Recovery from Fermented Broth via Forward Osmosis

Membranes ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 307
Author(s):  
Stavros Kalafatakis ◽  
Agata Zarebska ◽  
Lene Lange ◽  
Claus Hélix-Nielsen ◽  
Ioannis V. Skiadas ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Forward Osmosis ◽  
Cross Flow ◽  
Feed Solution ◽  
Mitigation Strategies ◽  
Water Recovery ◽  
Operational Parameters ◽  
Solution Ph ◽  
Sustainable Solutions ◽  
Cross Flow Velocity

Forward Osmosis (FO) is a promising technology that can offer sustainable solutions in the biorefinery wastewater and desalination fields, via low energy water recovery. However, microbial biomass and organic matter accumulation on membrane surfaces can hinder the water recovery and potentially lead to total membrane blockage. Biofouling development is a rather complex process and can be affected by several factors such as nutrient availability, chemical composition of the solutions, and hydrodynamic conditions. Therefore, operational parameters like cross-flow velocity and pH of the filtration solution have been proposed as effective biofouling mitigation strategies. Nevertheless, most of the studies have been conducted with the use of rather simple solutions. As a result, biofouling mitigation practices based on such studies might not be as effective when applying complex industrial mixtures. In the present study, the effect of cross-flow velocity, pH, and cell concentration of the feed solution was investigated, with the use of complex solutions during FO separation. Specifically, fermentation effluent and crude glycerol were used as a feed and draw solution, respectively, with the purpose of recirculating water by using FO alone. The effect of the abovementioned parameters on (i) ATP accumulation, (ii) organic foulant deposition, (iii) total water recovery, (iv) reverse glycerol flux, and (v) process butanol rejection has been studied. The main findings of the present study suggest that significant reduction of biofouling can be achieved as a combined effect of high-cross flow velocity and low feed solution pH. Furthermore, cell removal from the feed solution prior filtration may further assist the reduction of membrane blockage. These results may shed light on the challenging, but promising field of FO process dealing with complex industrial solutions.

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