Showing papers on "Fouling published in 2013"
TL;DR: A novel kind of superhydrophilic hybrid membranes for effective oil/water separation prepared by depositing CaCO3-based mineral coating on PAA-grafted polypropylene microfiltration membranes, endowing the membranes with underwater superoleophobicity are reported.
Abstract: Oil-polluted water is a worldwide problem due to the increasing industrial oily wastewater and the frequent oil spill accidents. Here, we report a novel kind of superhydrophilic hybrid membranes for effective oil/water separation. They were prepared by depositing CaCO3-based mineral coating on PAA-grafted polypropylene microfiltration membranes. The rigid mineral-coating traps abundant water in aqueous environment and forms a robust hydrated layer on the membrane pore surface, thus endowing the membranes with underwater superoleophobicity. Under the drive of either gravity or external pressure, the hybrid membranes separate a range of oil/water mixtures effectively with high water flux (>2000 L m−2 h−1), perfect oil/water separation efficiency (>99%), high oil breakthrough pressure (>140 kPa) and low oil fouling. The oil/water mixtures include not only free mixtures but also oil-in-water emulsions. Therefore, the mineral-coated membrane enables an efficient and energy-saving separation for various oil/water mixtures, showing attractive potential for practical oil/water separation.
308 citations
TL;DR: In this paper, a commercial polyamide reverse osmosis (RO) membrane was surface modified with polydopamine deposited from buffered, aqueous dopamine solution at ambient conditions.
261 citations
TL;DR: In this article, the authors investigated the membrane fouling behavior in forward osmosis under conditions simulating the osmotic dilution process and the use of hydrodynamic methods without using any cleaning chemicals.
231 citations
TL;DR: In this paper, a novel approach was explored to obtain a highly hydrophilic membrane surface via plasma induced grafting of polyethylene glycol (PEG) and subsequent TiO2 particles deposition onto the membrane surface The mechanism of oil affinity onto a membrane surface was quantitatively investigated by the extended Derjaguin-Landau-Verwey-Overbeek theory.
213 citations
TL;DR: In this paper, a polyethersulfone (PES) flat-sheet membrane was manufactured by the phase inversion method for wastewater treatment application, and the nanoparticles size distribution was characterized by scanning electron microscope (SEM) and dynamic light scattering (DLS) method to explore the effect of nanoparticle aggregation.
213 citations
TL;DR: Although the obtained power density reduced with approximately 40% in the first day under these conditions, caused by organic fouling, several strategies are available to maintain a high power output using reverse electrodialysis.
211 citations
TL;DR: In this article, the authors compared the performance and fouling mechanisms of polymeric and ceramic microfiltration of model feed solutions containing polyethylene glycol or Suwannee River humic acid as well as a synthetic river water and performed a systematic comparison with polymeric membrane filtration.
196 citations
TL;DR: In this paper, the application of membrane bioreactor in treating high strength industrial wastewater by analysing operational parameters, limitations and mitigations of MBR for industrial wastewater is reviewed.
192 citations
TL;DR: The biopolymers quantified with liquid chromatography-organic carbon detection showed a remarkable correlation with UF membrane fouling for all the three water sources at different seasons, suggesting that the biopolymer content in water can be employed as a universal indicator for predicting membranes fouling potential in UF processes.
190 citations
TL;DR: A detailed survey on hot gas filtration can be found in this article, where the main focus is on the review of hot gas filter media as well as hot gas filtering systems.
190 citations
TL;DR: In this paper, the effectiveness of the bioprocess in delaying membrane wetting and the significance of the biofouling on flux decline was investigated. But, the results were limited to 13 days and the MDBR flux was not maintained at more than 6.8 L/m 2 h.
TL;DR: Nanofiltration (NF) is one of the widely used membrane processes for water and wastewater treatment in addition to other applications such as desalination as mentioned in this paper, which has replaced reverse osmosis (RO) membranes in many applications due to lower energy consumption and higher flux rates.
Abstract: . The application of membrane technology in water and wastewater treatment is increasing due to stringent water quality standards. Nanofiltration (NF) is one of the widely used membrane processes for water and wastewater treatment in addition to other applications such as desalination. NF has replaced reverse osmosis (RO) membranes in many applications due to lower energy consumption and higher flux rates. This paper briefly reviews the application of NF for water and wastewater treatment including fundamentals, mechanisms, fouling challenges and their controls.
TL;DR: This work presents the first fabrication of an antifouling thin-film composite FO membrane by an in situ technique without postfabrication treatment, and shows a significantly lower flux decline for the in situ modified membranes compared to pristine polyamide.
Abstract: Forward osmosis (FO) is an emerging membrane-based water separation process with potential applications in a host of environmental and industrial processes. Nevertheless, membrane fouling remains a technical obstacle affecting this technology, increasing operating costs and decreasing membrane life. This work presents the first fabrication of an antifouling thin-film composite (TFC) FO membrane by an in situ technique without postfabrication treatment. The membrane was fabricated and modified in situ, grafting Jeffamine, an amine-terminated poly(ethylene glycol) derivative, to dangling acyl chloride surface groups on the nascent polyamide active layer. Surface characterization by contact angle, Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), zeta potential, atomic force microscopy (AFM), and fluorescence microscopy, confirms the presence of Jeffamine on the membrane surface. We demonstrate the improved fouling resistance of the in situ modified membranes through accelerated dynamic fouling FO experiments using a synthetic wastewater feed solution at high concentration (250 mg/L) of alginate, a model macromolecule for the hydrophilic fraction of wastewater effluent organic matter. Our results show a significantly lower flux decline for the in situ modified membranes compared to pristine polyamide (14.3 ± 2.7% vs 2.8 ± 1.4%, respectively). AFM adhesion force measurements between the membrane and a carboxylate-modified latex particle, a surrogate for the organic (alginate) foulant, show weaker foulant-membrane interactions, further confirming the enhanced fouling resistance of the in situ modified membranes.
TL;DR: In this paper, a novel membrane showing both hydrophilic and oleophobic surface properties was developed and evaluated for its resistance against organic and biological fouling in water and wastewater treatment.
TL;DR: In this paper, the authors compare the organic composition, molecular size distributions, and fouling and the mechanisms of fouling of ultrafiltration (UF) membranes for the surrogate materials sodium alginate, soluble microbial products (SMP), and commercial humic acid (HA) with the characteristics of EfOM and Suwannee River NOM.
TL;DR: In this paper, the authors systematically investigated membrane fouling by organic foulants in pressure retarded osmosis (PRO) process and its effect on PRO power density, and found that significant alginate fouling occurred when the draw solution (DS) contained large quantities of divalent cations.
TL;DR: In this article, the performance of forward osmosis (FO) at the pilot scale to achieve simultaneous seawater desalination and wastewater reclamation was evaluated with a commercial spiral wound FO membrane element for approximately 1300h of continuous operation.
TL;DR: A large number of technologies are being developed towards producing new coatings that will be able to resist biofouling over a period of years and thus truly replace biocides as antifouling systems.
TL;DR: Fouling of cellulose triacetate and thin-film composite forward osmosis (FO) membranes by organic macromolecules were studied using oppositely charged lysozyme and alginate as model foulants and solution chemistry had remarkable effect on the cake layer composition due to their effects on foulant-foulant interaction.
TL;DR: In this article, the authors used artificial neural networks (ANNs) to predict the permeation flux and fouling resistance, and then applied GA to optimize the operating conditions in separation of oil from industrial oily wastewaters, including trans-membrane pressure (TMP), cross-flow velocity (CFV), feed temperature and pH.
Abstract: In this work, treatment of oily wastewaters with commercial polyacrylonitrile (PAN) ultrafiltration (UF) membranes was investigated In order to do these experiments, the outlet wastewater of the API (American Petroleum Institute) unit of Tehran refinery, is used as the feed The purpose of this paper was to predict the permeation flux and fouling resistance, by applying artificial neural networks (ANNs), and then to optimize the operating conditions in separation of oil from industrial oily wastewaters, including trans-membrane pressure (TMP), cross-flow velocity (CFV), feed temperature and pH, so that a maximum permeation flux accompanied by a minimum fouling resistance, was acquired by applying genetic algorithm as a powerful soft computing technique The experimental input data, including TMP, CFV, feed temperature and pH, permeation flux and fouling resistance as outputs, were used to create ANN models This fact that there is an excellent agreement between the experimental data and the predicted values was shown by the modeling results Eventually, by multi-objective optimization, using genetic algorithm (GA), an optimization tool was created to predict the optimum operating parameters for desired permeation flux (ie maximum flux) and fouling resistance (ie minimum fouling) behavior The accuracy of the model is confirmed by the comparison between the predicted and experimental data
TL;DR: In this paper, a model microalgae Chlorella sorokiniana was used to characterize FO/PRO fouling in conjunction with water flux measurements, and a critical flux (critical concentration) behavior was revealed.
TL;DR: In this article, a semi-batch operation was employed with two membrane orientations in terms of active and support layers to assess the efficiency of a submerged forward osmosis (FO) system to reduce the volume of wastewater that needs to be treated while recovering high quality water that can be further treated for sustainable fresh water production.
TL;DR: In this article, a novel approach was taken to use nanoparticles as carriers and anchors for antifouling ligands, which were chemically functionalized by silane coupling agents, and further used to immobilize PEG molecules on their surface.
TL;DR: An air-cathode microbial osmotic fuel cell (MOFC) was developed in this article to improve energy recovery, and the performance of this new design was compared to conventional microbial fuel cells containing a cation (CEM) or anion exchange membrane (AEM).
TL;DR: In this article, the authors present a systematic review on the theoretical developments of mechanistic models related to the blocking filtration laws for describing the membrane fouling in membrane filtrations.
Abstract: Pore blocking is one of the critical factors governing the overall performance of membrane filtration systems. Pore blockage leads to a large resistance to filtration, giving rise to a sharp decline in the filtrate flux rate under constant pressure conditions and a severe increase in the pressure for operation under constant flux conditions during membrane filtration. In membrane filtration work, blocking filtration laws are widely used to interpret the membrane fouling in membrane filtration. This article presents a systematic review on the theoretical developments of mechanistic models related to the blocking filtration laws for describing the membrane fouling in membrane filtration. Equations for constant pressure and constant flux separations in the interstices of a membrane and on the surface are reported for the filtrate flow of Newtonian and power-law non-Newtonian fluids. The blocking filtration laws are useful also in the evaluation of the reduced pore size, maximum filtrate volume, and fouling p...
TL;DR: It was evident that the main contributor to physically irreversible fouling is the foulant-foulant interaction force, and the membrane flux recovery rate of fouled membranes is important for the control of membrane fouling.
Abstract: To further unravel the organic fouling behavior of polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes, the adhesion forces of membrane–foulant and foulant–foulant were investigated by atomic force microscopy (AFM) in conjunction with self-made PVDF colloidal probe and foulant-coated colloidal probe, respectively Fouling experiments with bovine serum albumin, sodium alginate, humic acid, and secondary wastewater effluent organic matter (EfOM) were carried out with PVDF UF membrane Results showed a positive correlation between the membrane–foulant adhesion force and the flux decline rate and extent in the initial filtration stage, whereas the foulant–foulant interaction force was closely related to the pseudostable flux and the cake layer structure in the later filtration stage For each type of foulant used, the membrane–foulant adhesion force was much stronger than the foulant–foulant interaction force, and membrane flux decline mainly occurred in the earlier filtration stage indicating that
TL;DR: In this paper, surface modification of a commercial TFC RO membrane was performed through redox initiated graft polymerization of N-isopropylacrylamide (NIPAm) followed by acrylic acid (AA) and the modified membrane showed improved membrane properties.
TL;DR: Overall results suggest that the MMV offers a good fouling control and the process was proven to be economically attractive.
TL;DR: In this paper, the effects of salt deposition, resulting from membrane dry-out, on the properties of two types of commercial hydrophobic membranes commonly used for MD purposes were investigated.
TL;DR: In this paper, the effect of membrane orientation on fouling behavior of forward osmosis (FO) membrane operated in FO mode (i.e., the dense layer facing the feed solution) and pressure-retarded (PRO) mode was investigated, and the results revealed that the FO membrane fouled more easily than when operated in the PRO mode and the fouling became more severe with increasing organic concentration in the feed solutions.