scholarly journals Reliable Sea Water Ro Operation with High Water Recovery and No-Chlorine/No-Sbs Dosing in Arabian Gulf, Saudi Arabia

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 141 ◽  
Author(s):  
Hiroki Miyakawa ◽  
Mohammed Maghram Al Shaiae ◽  
Troy N. Green ◽  
Yohito Ito ◽  
Yuichi Sugawara ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Sea Water ◽  
Surface Condition ◽  
Membrane Surface ◽  
Formation Rate ◽  
Arabian Gulf ◽  
High Water ◽  
Water Recovery ◽  
Permeate Flux ◽  
Autopsy Study

For providing advanced desalination the combination of the improvement of water recovery ratio in the reverse osmosis (RO) process and the No-Chlorine/No-Sodium Bisulfite (SBS) Dosing process was studied. In order to prevent membrane fouling even in high recovery water operations, an advanced two-stage design was implemented to (1) control the permeate flux through the RO membrane module, (2) optimize the system to reduce contaminant build-up and (3) eliminate the use of chlorine and SBS, which can accelerate membrane fouling. The system was evaluated by monitoring the biofouling and the microorganisms proliferation on the membrane surface based on membrane biofilm formation rate (mBFR). The pilot plant was operated in the condition of a water recovery rate of 55%. As a result, the system was operated for longer than four months without membrane cleaning (clean in place; CIP) and the possibility of operation for seven months without CIP was confirmed by the extrapolation of the pressure values. In addition, the mBFR is a reliable tool for water quality assessment, based on a comparison between the fouling tendency estimated from the mBFR and the actual membrane surface condition from autopsy study and the effectiveness No-Chlorine/No-SBS Dosing process was verified from mBFR of pretreated seawater.

Electroflocculation as potential pretreatment in colloid ultrafiltration

2006 ◽  
Vol 6 (1) ◽  
pp. 69-78 ◽  
Author(s):  
T. Harif ◽  
M. Hai ◽  
A. Adin
Keyword(s):  
Membrane Fouling ◽  
Colloidal Suspension ◽  
Membrane Surface ◽  
Constant Current ◽  
Permeate Flux ◽  
Batch Mode ◽  
Membrane Behavior ◽  
Flux Decline ◽  
Stainless Steel Cathode ◽  
Marginal Improvement

Electroflocculation (EF) is a coagulation/flocculation process in which active coagulant species are generated in situ by electrolytic oxidation of an appropriate anode material. The effect of colloidal suspension pretreatment by EF on membrane fouling was measured by flux decline at constant pressure. An EF cell was operated in batch mode and comprised two flat sheet electrodes, an aluminium anode and stainless steel cathode, which were immersed in the treated suspension, and connected to an external DC power supply. The cell was run at constant current between 0.06–0.2A. The results show that pre-EF enhances the permeate flux at pH 5 and 6.5, but only marginal improvement is observed at pH 8. At all pH values cake formation on the membrane surface was observed. The differences in membrane behavior can be explained by conventional coagulation theory and transitions between aluminium mononuclear species which affect particle characteristics and consequently cake properties. At pH 6.5, where sweep floc mechanism dominates due to increased precipitation of aluminium hydroxide, increased flux rates were observed. It is evident that EF can serve as an efficient pretreatment to ultrafiltration of colloid particles.

A Wall Film Model for Membrane Fouling

2018 ◽  
Author(s):  
Sina Jahangiri Mamouri ◽  
Volodymyr V. Tarabara ◽  
André Bénard
Keyword(s):  
Multiphase Flow ◽  
Membrane Fouling ◽  
Oil And Gas ◽  
Membrane Separation ◽  
Film Formation ◽  
Membrane Surface ◽  
Permeate Flux ◽  
Water Separation ◽  
Wall Film ◽  
Oil Water

Deoiling of produced or impaired waters associated with oil and gas production represents a significant challenge for many companies. Centrifugation, air flotation, and hydrocyclone separation are the current methods of oil removal from produced water [1], however the efficiency of these methods decreases dramatically for droplets smaller than approximately 15–20 μm. More effective separation of oil-water mixtures into water and oil phases has the potential to both decrease the environmental footprint of the oil and gas industry and improve human well-being in regions such as the Gulf of Mexico. New membrane separation processes and design of systems with advanced flow management offer tremendous potential for improving oil-water separation efficacy. However, fouling is a major challenge in membrane separation [2]. In this study, the behavior of oil droplets and their interaction with crossflow filtration (CFF) membranes (including membrane fouling) is studied using computational fluid dynamics (CFD) simulations. A model for film formation on a membrane surface is proposed for the first time to simulate film formation on membrane surfaces. The bulk multiphase flow is modeled using an Eulerian-Eulerian multiphase flow model. A wall film is developed from mass and momentum balances [3] and implemented to model droplet deposition and membrane surface blockage. The model is used to predict film formation and subsequent membrane fouling, and allow to estimate the actual permeate flux. The results are validated using available experimental data.

Influence of humic acid on the long-term performance of direct contact membrane distillation

2018 ◽  
Vol 30 (1) ◽  
pp. 109-120 ◽  
Author(s):  
Dong-Wan Cho ◽  
Gihoon Kwon ◽  
Jeongmin Han ◽  
Hocheol Song
Keyword(s):  
Humic Acid ◽  
Membrane Fouling ◽  
Coalbed Methane ◽  
Direct Contact ◽  
Membrane Surface ◽  
Membrane Distillation ◽  
Permeate Flux ◽  
Direct Contact Membrane Distillation ◽  
High Level

In this study, the influence of humic acid on the treatment of coalbed methane water by direct contact membrane distillation was examined with bench-scale test unit. During short-term distillation (1000 min), high level of humic acid above 50 ppm resulted in significant decrease in permeate flux, while low level of humic acid (∼2 ppm) had little influence on the flux. For the long-term distillation (5000 min), the flux decline began at 3400 min in the presence of 5 ppm humic acid and 5 mM Ca2+, and decreased to ∼40% of initial flux at 5000 min. The spectroscopic analysis of the membrane used revealed that the surface was covered by hydrophilic layers mainly composed of calcite. The membrane fouling effect of humic acid became more significant in the presence of Ca2+ due to more facile calcite formation on the membrane surface. It was demonstrated that humic acid enhanced CaCO3 deposition on the membrane surfaces, thereby expediting the scaling phenomenon.

Chemical pretreatment of feed water for membrane distillation

2008 ◽  
Vol 62 (1) ◽  
Author(s):  
Marek Gryta
Keyword(s):  
Membrane Fouling ◽  
Membrane Surface ◽  
Membrane Distillation ◽  
Feed Water ◽  
Chemical Pretreatment ◽  
Permeate Flux ◽  
Membrane Scaling ◽  
Water Pretreatment ◽  
Energy Dispersion Spectrometry ◽  
Process Operation

AbstractMembrane distillation was used to produce demineralized water from ground water. The influence of feed water pretreatment carried out in a contact clarifier (softening with Ca(OH)2 and coagulation with FeSO4 · 7H2O) followed by filtration, on the process effectiveness was evaluated. It was found that the chemical pretreatment decreased the membrane fouling; however, the degree of water purification was insufficient because precipitation of small amounts of deposit on the membrane surface during the process operation was still observed. The permeate flux was gradually decreasing as a result of scaling. The morphology and composition of the fouling layer were studied using scanning electron microscopy coupled with energy dispersion spectrometry. The presence of significant amounts of silica, apart from calcium and magnesium, was determined in the formed deposit. The removal of foulants by heterogeneous crystallization performed inside the filter (70 mesh), assembled directly at the module inlet, was found to be a solution preventing the membrane scaling.

A real trial of a long-term non-fouling membrane bioreactor for saline sewage treatment

2011 ◽  
Vol 63 (7) ◽  
pp. 1519-1523 ◽  
Author(s):  
Peng Bai ◽  
Jin Wang ◽  
Guang-Hao Chen
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Membrane Surface ◽  
Pilot Trial ◽  
Sewage Treatment ◽  
Power Source ◽  
Permeate Flux ◽  
Mixing Condition ◽  
Water Ratio

This paper reports on a pilot trial of a novel MBR developed with coarse-pore membrane module by the authors. The plant was operated for 370 days with up to 7 m3/d raw saline sewage after 3-mm screening. The plant performed successfully without membrane fouling for 270 days except an accidental power source failure for 30 h, during which membrane was fouled under no aeration and mixing condition. EPS increases in both the reactor and the bio-cake on the membrane surface explained this fouling. The average TSS, COD and TKN removal efficiency were 92, 90, and 93%, respectively, under a high effective permeate flux of 4.8 m/d and a low air-to-water ratio of 15.

Description of different effects of in-line coagulation upon semi-dead-end ultrafiltration

2003 ◽  
Vol 3 (5-6) ◽  
pp. 337-344 ◽  
Author(s):  
W. Doyen ◽  
R. Vandaele ◽  
B. Molenberghs ◽  
J. Cromphout ◽  
P. Bielen ◽  
...  
Keyword(s):  
Surface Water ◽  
Membrane Surface ◽  
Environmental Scanning Electron Microscopy ◽  
High Volume ◽  
High Water ◽  
Transmembrane Pressure ◽  
Water Recovery ◽  
Dead End ◽  
Cake Layer ◽  
Cake Porosity

This paper describes the results of research focussed on the different effects of in-line coagulation (FeCl3), towards the operation of semi-dead-end UF for drinking water and process water production starting from surface water. In this research, firstly the effects of the use of FeCl3 on the formed cake were studied, by both direct and indirect measurements. Using the ESEM technique (environmental scanning electron microscopy), which enables one to make pictures of wet samples, we observed that cake thickness was much higher upon use of FeCl3 (20 instead of 2 μm). As a result, the cake porosity was calculated to be much higher with than without coagulant use (93% instead of 37%). From the stability (nonincreasing) of the starting transmembrane pressure (TMP) in the successive filtration cycles, upon semidead-end operation, it was concluded that cake layer was less prone to adhere to the membrane surface when using coagulant. This is even more emphasized once the dosing is stopped, as a consequence the TMP rises very steeply under difficult circumstances, such as; high flux rates, high water recovery rates, and the use of membranes made from polymers with high adsorption properties. Secondly, indirect effects of the use of coagulant on filtration behaviour were investigated. Thus, it was found that TMP increase in the filtration cycle was much lower, due to depth filtration in the formed high-volume cake, and TMP was much more stable over a long time. These observations were in good agreement with found higher cake porosity. Moreover, it was observed that due to the use of a coagulant, the influences of membrane polymer nature and membrane structure disappeared, cleaning action could be postponed and cleaning aggressiveness could be lowered. In addition, water recovery and flux rate could be increased, and influence of seasonal water quality variations could be better faced. Finally, it was found that the treatment of surface water with high DOC content (e.g. 10 mg DOC/l) was enabled.

scholarly journals The color removal and fate of organic pollutants in a pilot-scale MBR-NF combined process treating textile wastewater with high water recovery

2015 ◽  
Vol 73 (6) ◽  
pp. 1426-1433 ◽  
Author(s):  
Kun Li ◽  
Chao Jiang ◽  
Jianxing Wang ◽  
Yuansong Wei
Keyword(s):  
Membrane Fouling ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
High Water ◽  
Pilot Scale ◽  
Water Yield ◽  
Water Recovery ◽  
Treatment Efficiency ◽  
Textile Mill ◽  
Refractory Compounds

A combination of membrane bioreactor (MBR) and nanofiltration (NF) was tested at pilot-scale treating textile wastewater from the wastewater treatment station of a textile mill in Wuqing District of Tianjin (China). The MBR-NF process showed a much better treatment efficiency on the removal of the chemical oxygen demand, total organic carbon, color and turbidity in comparison with the conventional processes. The water recovery rate was enhanced to over 90% through the recycling of NF concentrate to the MBR, while the MBR-NF showed a stable permeate water quality that met with standards and could be directly discharged or further reused. The recycled NF concentrate caused an accumulation of refractory compounds in the MBR, which significantly influenced the treatment efficiency of the MBR. However, the sludge characteristics showed that the activated sludge activity was not obviously inhibited. The results of fluorescence spectra and molecular weight distribution indicated that those recalcitrant pollutants were mostly protein-like substances and a small amount of humic acid-like substances (650–6,000 Da), which contributed to membrane fouling of NF. Although the penetrated protein-like substances caused the residual color in NF permeate, the MBR-NF process was suitable for the advanced treatment and reclamation of textile wastewater under high water yield.

scholarly journals A Unified, One Fluid Model for the Drag of Fluid and Solid Dispersals by Permeate Flux towards a Membrane Surface

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 154
Author(s):  
Amgad Salama ◽  
Shuyu Sun ◽  
Tao Zhang
Keyword(s):  
Hyperbolic Equation ◽  
Membrane Fouling ◽  
Fluid Model ◽  
Membrane Surface ◽  
Numerical Approach ◽  
Domain Model ◽  
Permeate Flux ◽  
Modeling Framework ◽  
Computational Burden ◽  
Averaging Techniques

The drag of dispersals towards a membrane surface is a consequence of the filtration process. It also represents the first step towards the development of the problem of fouling. In order to combat membrane fouling, it is important to understand such drag mechanisms and provide a modeling framework. In this work, a new modeling and numerical approach is introduced that is based on a one-domain model in which both the dispersals and the surrounding fluid are dealt with as a fluid with heterogeneous property fields. Furthermore, because of the fact that the geometry of the object assumes axial symmetry and the configuration remains fixed, the location of the interface may be calculated using geometrical relationships. This alleviates the need to define an indicator function and solve a hyperbolic equation to update the configuration. Furthermore, this approach simplifies the calculations and significantly reduces the computational burden required otherwise if one incorporates a hyperbolic equation to track the interface. To simplify the calculations, we consider the motion of an extended cylindrical object. This allows a reduction in the dimensions of the problem to two, thereby reducing the computational burden without a loss of generality. Furthermore, for this particular case there exists an approximate analytical solution that accounts for the effects of the confining boundaries that usually exist in real systems. We use such a setup to provide the benchmarking of the different averaging techniques for the calculations of properties at the cell faces and center, particularly in the cells involving the interface.

Numerical Simulation of Filtration of Charged Oil Particles in Stationary and Rotating Tubular Membranes

2015 ◽  
Author(s):  
Sina Jahangiri Mamouri ◽  
Volodymyr V. Tarabara ◽  
André Bénard
Keyword(s):  
Flow Field ◽  
Electric Field ◽  
Electric Potential ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Cross Flow ◽  
Solid Cylinder ◽  
Permeate Flux ◽  
Cross Flow Filtration ◽  
Flow Filtration

Cross flow filtration (CFF) is a common membrane separation process with applications in food, biochemical and petroleum industries. In particular, membranes can be used for liquid-liquid separation processes such as needed in oil-water separation. A major challenge in cross flow filtration is membrane fouling. It can decrease significantly the permeate flux and a membrane’s efficiency. Membrane fouling can be mitigated by inducing shear on the membrane’s surface and this can be enhanced by inducing a swirl in the flow. In addition, a possible approach to improve membrane efficiency consists of repelling droplets/particles from the porous surface toward the centerline using a repulsive electric force. For this purpose, the surface of the membrane can be exposed to electric potential and droplets/particles are also induced to have the same electric charge. In this work, numerical simulations of charged non-deformable droplets moving within an axially rotating charged tubular membrane are performed. The results show that by increasing the electric potential on the membrane surface, the repelling force increases which obviously improves the grade efficiency of the membrane. However, the electric field gradients found in the flow field require large potentials on the membrane surface to observe a noticeable effect. Hence, a smaller solid cylinder is located in the centerline of the flow channel with zero potential. This solid cylinder enhances the electric field gradient in the domain which results in higher repelling forces and larger grade efficiency of the membrane at small potentials. The addition of a small cylinder in the flow field also improves the grade efficiency increases due to the higher shear stress near the membrane surface.

scholarly journals Fouling Mitigation via Chaotic Advection in a Flat Membrane Module with a Patterned Surface

Membranes ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 724
Author(s):  
Kyung Tae Kim ◽  
Jo Eun Park ◽  
Seon Yeop Jung ◽  
Tae Gon Kang
Keyword(s):  
Growth Rate ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Film Theory ◽  
Groove Depth ◽  
Membrane Module ◽  
Chaotic Advection ◽  
Permeate Flux ◽  
Fouling Mitigation ◽  
Flat Membrane

Fouling mitigation using chaotic advection caused by herringbone-shaped grooves in a flat membrane module is numerically investigated. The feed flow is laminar with the Reynolds number (Re) ranging from 50 to 500. In addition, we assume a constant permeate flux on the membrane surface. Typical flow characteristics include two counter-rotating flows and downwelling flows, which are highly influenced by the groove depth at each Re. Poincaré sections are plotted to represent the dynamical systems of the flows and to analyze mixing. The flow systems become globally chaotic as the groove depth increases above a threshold value. Fouling mitigation via chaotic advection is demonstrated using the dimensionless average concentration (c¯w*) on the membrane and its growth rate. When the flow system is chaotic, the growth rate of c¯w* drops significantly compared to that predicted from the film theory, demonstrating that chaotic advection is an attractive hydrodynamic technique that mitigates membrane fouling. At each Re, there exists an optimal groove depth minimizing c¯w* and the growth rate of c¯w*. Under the optimum groove geometry, foulants near the membrane are transported back to the bulk flow via the downwelling flows, distributed uniformly in the entire channel via chaotic advection.

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