Influence of water compositions on fouling of plane organic membrane in frontal filtration: application to water and wastewater clarification

2010 ◽  
Vol 61 (9) ◽  
pp. 2283-2291
Author(s):  
P. Sridang ◽  
P. Wanichapichart ◽  
A. Grasmick
Keyword(s):  
Hydraulic Resistance ◽  
Membrane Fouling ◽  
Film Formation ◽  
Applied Pressure ◽  
Porous Membrane ◽  
Resistance Coefficient ◽  
Treated Wastewater ◽  
Feed Water ◽  
Cake Filtration ◽  
Inorganic Matter

The aim of this study was to evaluate and quantify the filterability of suspended/soluble organic and suspended inorganic matter in a condition without and with chemical conditioning on membrane fouling using cake filtration model. The experiments were conducted with different feed water concentrations under a given TMP (0.2 to 0.5 bar). The fouling potential was examined and described in terms of resistance coefficient (α·W) and specific resistance (α). The results showed an increase of α·W and α within the concentration of wastewater samples tested. The soluble fractions in wastewater induced fouling and its mechanism was due both to the interaction of soluble organic components and also some of the particular colloids in MLSS, causing irreversible fouling, followed by thin film formation on membrane surfaces with low porosity, dense structure and also internal fouling. This phenomenon promoted the values of α·W and α from final treated wastewater 5–20 times higher than in bentonite suspension and on reservoir surface water. Higher pressure than 0.2 bar induced greater hydraulic resistance values than lower applied pressure. The pore size of the porous membrane did not show any difference in the values of α·W and α obtained, but they mostly depended on the water composition tested. The hydraulic resistance values appeared largely to minimise when using chemical conditioning because of cake forming as a dynamic membrane that reduced the irreversible fouling phenomena giving a constant filtration rate.

Comparison of the Filterability of Mineral, Organic and Mixed Suspensions Application to Water Clarification

2012 ◽  
Author(s):  
P. Choksuchart Sridang ◽  
M. Heran ◽  
A. Grasmick
Keyword(s):  
Activated Carbon ◽  
Hydraulic Resistance ◽  
Membrane Fouling ◽  
Ferric Hydroxide ◽  
Membrane System ◽  
Porous Membrane ◽  
Resistance Coefficient ◽  
Permeability Evolution ◽  
Cake Filtration ◽  
Mineral Suspensions

Filtration operations were conducted on porous membrane to evaluate the specific contribution of the main fractions encountered in raw water (solids in suspension, soluble, or colloidal compounds) on the system permeability evolution during industrial operations. Experiments were conducted in a frontal filtration mode with single or mixed synthetic suspensions (clay, ferric hydroxide, activated carbon, latex, and humic acids). Results showed a wild specific resistance coefficient (α.W) difference between mineral and organic suspensions. The α.W coefficient increased with suspended solids concentrations. On the other hand, no actual differences were observed between the tested mineral suspensions, which also presented no actual differences in particle size distribution. In the same condition, latex suspensions composed by smaller elements induced higher hydraulic resistance, comparatively to mineral suspension, the resistance coefficient values were ten to one hundred times greater than the mineral suspensions. Nevertheless, a latex suspensions conditioning with FeCl3 allowed a notably reducing of the resistance coefficient. Moreover, experiments on humic acid suspension pointed out the membrane fouling during filtration, which could disappear in the presence of activated carbon in the suspension. Since similar results were obtained in an immersed membrane system, it can be considered that this methodology can be developed to characterise the filterability of natural suspensions, and optimise the suspension conditioning. Key words: Water clarification, cake filtration, porous membrane, hydraulic resistance, synthetic suspensions

Control of RO/NF organic fouling by monitoring and modification of organic polarity of feed water

2008 ◽  
Vol 8 (4) ◽  
pp. 467-472 ◽  
Author(s):  
J. Y. Hu ◽  
J. H. Shan
Keyword(s):  
Membrane Fouling ◽  
Rapid Assessment ◽  
Membrane System ◽  
Assessment Method ◽  
Treated Wastewater ◽  
Feed Water ◽  
Rapid Assessment Method ◽  
Organic Fractions ◽  
Pre Treatment ◽  
The Relationship

The organics in surface water and treated wastewater were analyzed for their polarity by a modified natural organic matter polarity rapid assessment method (NOM-PRAM). Selected water samples were then introduced to reverse osmosis (RO) and nanofiltration (NF) membrane system to study the relationship between organics polarity and membrane fouling. Results showed that the more organic fractions with non-polar property, the more serious fouling found for both RO and NF. Pre-treatment with KMnO4 was then conducted to modify the organics polarity in feed water. Under the optimum dosage, where more non-polar organics were converted to polar or negatively charged fractions, the subsequent membrane fouling was found to be reduced.

New parameter for monitoring fouling during ultrafiltration of WWTP effluent

2001 ◽  
Vol 43 (10) ◽  
pp. 241-248 ◽  
Author(s):  
J. H. Roorda ◽  
J. H.J.M. van der Graaf
Keyword(s):  
Water Quality ◽  
Membrane Fouling ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Waste Water Treatment Plant ◽  
Feed Water ◽  
Sufficient Information ◽  
Cake Filtration ◽  
Ultrafiltration Membranes ◽  
Wwtp Effluent

Abstract Variations in water quality of waste water treatment plant (WWTP) effluent complicate ultrafiltration of this feed water. Traditional parameters do not provide sufficient information to explain the fouling of membranes during ultrafiltration of WWTP effluent. New parameters for measuring and monitoring the fouling potential of feed water for ultrafiltration membranes need to be developed. The normalised membrane fouling index for ultrafiltration membranes (MFI-UFn) can be used as such and is according to the cake filtration theory calculated from the ratio of filtration time and filtration volume as a function of the filtration volume. MFI-UFn can be calculated from both experiments with constant Trans Membrane Pressure (TMP) and from experiments with constant flux. This parameter can also be calculated independent of the scale of the experiment. Results show that differences in fouling potential can be measured for various feed waters using the same membrane type and for various membrane types using the same feed water. Variation in feed water quality leads to a deviation of the MFI-UFn, as was found especially for WWTP effluent. The applied TMP influences the value of the MFI-UFn, indicating cake compression when applying a higher TMP. MFI-UFn can be used to identify the effect of pre-treatment methods, which is useful when using WWTP effluent as feed water for an ultrafiltration processes.

Comparative experimental study on fouling mechanisms in nano-porous membrane: cheese whey ultrafiltration as a case study

2016 ◽  
Vol 74 (12) ◽  
pp. 2737-2750 ◽  
Author(s):  
Mohammad Torkamanzadeh ◽  
Mohsen Jahanshahi ◽  
Majid Peyravi ◽  
Ali Shokuhi Rad
Keyword(s):  
Membrane Fouling ◽  
Porous Membrane ◽  
Quantitative Prediction ◽  
Layer Formation ◽  
Cake Filtration ◽  
Operational Conditions ◽  
Cake Layer ◽  
Classical Models ◽  
Pore Blockage ◽  
Relative Errors

Determination of fouling mechanisms and accurate quantitative prediction of nano-porous membrane behavior are of great interest in membrane processes. This work has focused on a comprehensive comparison of two classical and new fouling models. Different operational conditions were tested to analyze the level of agreement of these models with experimental observation. Whey solutions of 8, 0.8 and 0.5 g/L were ultrafiltered in transmembrane pressures (TMPs) of 300 and 500 KPa through a synthesized polyethersulfone/copolymer blend membrane. Fouling mechanisms and the effect of different combinations of TMPs and protein concentrations were determined and analyzed by fitting the experimental data to different models. Based on the results obtained from classical models, it was found that the predictions of the cake layer formation model were quite acceptable, followed by the intermediate blocking model. The new combined pore blockage-cake filtration model, however, was found to be very successful in predicting the flux decline over time for every operational condition tested, with all relative errors of prediction less than 5%. The latter also showed a good performance in the transition from the pore blockage mechanism to cake layer formation.

scholarly journals Pilot Study on the Combination of Different Pre-Treatments with Nanofiltration for Efficiently Restraining Membrane Fouling While Providing High-Quality Drinking Water

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 380
Author(s):  
Yan Chen ◽  
Huiping Li ◽  
Weihai Pang ◽  
Baiqin Zhou ◽  
Tian Li ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Post Treatment ◽  
Size Exclusion ◽  
Transmembrane Pressure ◽  
Feed Water ◽  
High Quality ◽  
Treated Water

Nanofiltration (NF) is a promising post-treatment technology for providing high-quality drinking water. However, membrane fouling remains a challenge to long-term NF in providing high-quality drinking water. Herein, we found that coupling pre-treatments (sand filtration (SF) and ozone–biological activated carbon (O3-BAC)) and NF is a potent tactic against membrane fouling while achieving high-quality drinking water. The pilot results showed that using SF+O3-BAC pre-treated water as the feed water resulted in a lower but a slowly rising transmembrane pressure (TMP) in NF post-treatment, whereas an opposite observation was found when using SF pre-treated water as the feed water. High-performance size-exclusion chromatography (HPSEC) and three-dimensional excitation–emission matrix (3D-EEM) fluorescence spectroscopy determined that the O3-BAC process changed the characteristic of dissolved organic matter (DOM), probably by removing the DOM of lower apparent molecular weight (LMW) and decreasing the biodegradability of water. Moreover, amino acids and tyrosine-like substances which were significantly related to medium and small molecule organics were found as the key foulants to membrane fouling. In addition, the accumulation of powdered activated carbon in O3-BAC pre-treated water on the membrane surface could be the key reason protecting the NF membrane from fouling.

scholarly journals Application of forward osmosis in reusing the brackish concentrate produced in reverse osmosis plants with secondary treated wastewater as feed solution: a case study

2016 ◽  
Vol 6 (4) ◽  
pp. 533-543 ◽  
Author(s):  
W. D. Wang ◽  
M. Esparra ◽  
H. Liu ◽  
Y. F. Xie
Keyword(s):  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Water Flux ◽  
Forward Osmosis ◽  
Pump Energy ◽  
Feed Solution ◽  
Disinfection Byproducts ◽  
Treated Wastewater ◽  
Membrane Flux ◽  
Flux Decline

This study evaluated the feasibility of forward osmosis (FO) in diluting and reusing the concentrate produced in a reverse osmosis (RO) plant in James City County, VA. Secondary treated wastewater (STW) was used as the feed solution. Findings indicated that pH had slight effects on the water flux of the FO membrane. As the concentration of total dissolved solids (TDS) in the concentrate was diluted from 12.5 to 1.0 g/L or the temperature in the STW decreased from 23 to 10 °C, the membrane flux decreased from 2.2 to 0.59 and 0.81 L/(m2 h), respectively. The FO membrane showed a good performance in the rejection of organic pollutants, with only a small part of the protein-like substances and disinfection byproducts permeating to the diluted concentrate. During an 89-hour continuous operation, water flux decline due to membrane fouling was not observed. Controlling the TDS in the second-stage FO effluent at 1.5 g/L, approximately 8.3% of the pump energy input could be saved. The consumption of groundwater was reduced from 22.7 × 103 to 10.6 × 103 m3/d. FO was proved to be an effective method in both diluting the discharged concentrate and reducing the energy consumption of RO.

scholarly journals A feasibility study on UV pretreatment for microfiltration and reverse osmosis membrane processes in wastewater reclamation

2013 ◽  
Vol 3 (3) ◽  
pp. 260-267
Author(s):  
Ho-Young Jeong ◽  
Yoon-Jin Kim ◽  
Ji-Hee Han ◽  
Dong-Ha Kim ◽  
Jinsik Sohn ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Treatment Options ◽  
Human Consumption ◽  
Feed Water ◽  
Reverse Osmosis Membrane ◽  
Wastewater Reclamation ◽  
Important Place ◽  
Quality Water ◽  
Small Footprint

Wastewater reclamation is where wastewater from various sources is purified so the water can be used by human consumption. Among many treatment options, membranes have gained an important place in wastewater reclamation. It allows the production of high quality water from wastewater, with a small footprint and affordable energy consumption. Nevertheless, membrane fouling is regarded as a serious problem due to the high fouling potential of wastewater. In this study, we applied ultraviolet (UV) processes as a pretreatment for membrane systems that are used for wastewater reclamation. Low pressure UV (LUV) and pulsed UV (PUV) were used to decompose or alter the organics in the feed water of the membranes. Effluent organic matter was characterized by total organic carbon (TOC) and UV absorbance (UVA). Also the effect of UV pretreatment on membrane fouling was investigated for microfiltration (MF) and reverse osmosis (RO) processes. The pretreatment of membranes using LUV or PUV was effective to control fouling of hollow fiber MF membranes. This is probably because of the reduction and modification of organics after UV treatments. However, the effect of UV pretreatment on RO flux was less significant, which is attributed to low fouling prophecy after MF treatment.

scholarly journals Vapor Trapping Membrane for Reverse Osmosis

2010 ◽  
Author(s):  
Jongho Lee ◽  
Sean O’Hern ◽  
Rohit Karnik ◽  
Tahar Laoui
Keyword(s):  
Water Vapor ◽  
Reverse Osmosis ◽  
Calcium Ion ◽  
Size Range ◽  
Salt Water ◽  
Applied Pressure ◽  
Flux Measurement ◽  
Feed Water ◽  
Self Assembled Monolayer ◽  
Microfluidic Flow

This paper presents a concept for desalination by reverse osmosis (RO) using a vapor-trapping membrane. The membrane is composed of hydrophobic nanopores and separates the feed salt water and the fresh water (permeate) side. The feed water is vaporized by applied pressure and the water vapor condenses on the permeate side accompanied by recovery of latent heat. A probabilistic model was developed for transport of water vapor inside the nanopores, which predicted 3–5 times larger mass flux than conventional RO membranes at temperatures in the range of 30–50°C. An experimental method to realize short and hydrophobic nanopores is presented. Gold was deposited at the entrance of alumina pores followed by modification using an alkanethiol self-assembled monolayer. The membranes were tested for defective or leaking pores using a calcium ion indicator (Fluo-4). This method revealed the existence of defect-free areas in the 100–200 μm size range that are sufficient for flux measurement. Finally, a microfluidic flow cell was created for characterizing the transport properties of the fabricated membranes.

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.

Gas sparged cross-flow microfiltration of biologically treated wastewater

2000 ◽  
Vol 41 (10-11) ◽  
pp. 173-180 ◽  
Author(s):  
L. Vera ◽  
S. Delgado ◽  
S. Elmaleh
Keyword(s):  
Shear Stress ◽  
Membrane Fouling ◽  
Cross Flow ◽  
Solid Content ◽  
Treated Wastewater ◽  
Inorganic Membrane ◽  
Form Complex ◽  
Cross Flow Filtration ◽  
Mass Transport Process ◽  
Flow Filtration

A novel technique was tested for reducing tubular mineral membrane fouling by injecting gas into a cross-flow stream. The injected gas is thought to form complex hydrodynamic conditions inside the microfiltration module, which increase the wall shear stress, preventing the membrane fouling and enhancing the microfiltration mass transfer. The experimental study was carried out with biologically treated wastewater filtered through a tubular inorganic membrane (Carbosep M14). The flux, monotonously increasing with gas velocity, was more than tripled. New dimensionless quantities of shear stress number and resistance number were developed by generalisation of the dimensional analysis already carried out for the steady state flux of classical unsparged cross-flow filtration. A unique formalism allowed then interpreting the experimental results of both classical diphasic filtration and sparged filtration. The main limiting mass transport process was due to the solid content.

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