Ceramic Hollow Fiber Membrane Research Articles

Fabrication, performance evaluation, and optimisation of adsorptive ammonia removal using hollow fibre ceramic membrane: Response surface methodology approach

Abstract This work aims to optimise the factors that affect the adsorptive removal of ammonia by natural zeolite hollow fibre ceramic membrane (HFCM) in a continuous crossflow system using surface response methodology (RSM). The adsorptive HFCM was first characterised using the scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy prior to the adsorption process. A face-centred central composite design (CCD) was used to statistically visualise the interaction of the factors, namely feed pH, feed concentration, and HFCM dosage, with the response of water permeability and ammonia removal of the HFCM. The optimum conditions for the HFCM performance were feed pH of 7.04, feed concentration of 75.00 mg/L, and HFCM dosage of 0.35 g, with a desirability value of 0.953. The excellent ammonia removal performance (96.5%) reveals that the HFCM possesses great potential to be developed as a synergised system that combines the adsorption and filtration of water.

Novel silica sand hollow fibre ceramic membrane for oily wastewater treatment

Hollow fibre ceramic membranes are well-known to have unique characteristics, including superior thermal, chemical, and mechanical stabilities. The main drawback of ceramic membranes that limits their commercialisation is their high cost of raw materials. To overcome this disadvantage, a low-cost silica sand-based hollow fibre ceramic membrane (SS-HFCM) was successfully fabricated via combined phase inversion/sintering technique. Prior to fabrication, silica sand powder was first characterised using X-ray fluorescence (XRF), X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), and Fourier transform infrared spectroscopy (FTIR) analyses. Furthermore, the morphology and mechanical strength were investigated using scanning electron microscopy (SEM) and three-point bending test, respectively. The effects of two major fabrication process parameters (i.e., sintering temperature and ceramic content) on the mechanical strength, morphology, pure water flux (PWF), and oily-water separation of the SS-HFCM were examined. Based on the findings, the most suitable sintering temperature was 1300 °C. Satisfactory morphological structure and strength of sponge- and finger-like voids at 55 wt% ceramic powder loading was found to be advantageous for the characteristics of the fabricated SS-HFCM. The mechanical strength of 210 MPa was obtained at the sintering temperature and content loading of 1300 °C and 57.5 wt%, respectively. The mechanical strength of SS-HFCM obtained at 1300 °C in this work is significantly higher than those reported in previous studies. Furthermore, enhanced oil-water separation performance was obtained with the highest oil rejection rate of 99.7%. This SS-HFCM has a satisfactory structure with functional inner and outer layers of separation, which can be beneficial for water treatment applications, such as microfiltration, ultrafiltration, membrane distillation, and membrane contactor.

Superhydrophobic Ball Clay Based Ceramic Hollow Fiber Membrane via Universal Spray Coating Method for Membrane Distillation

Superhydrophobic Ball Clay Based Ceramic Hollow Fiber Membrane via Universal Spray Coating Method for Membrane Distillation

Design and characterization of ceramic hollow fiber membrane derived from waste ash using phase inversion-based extrusion/sintering technique for water filtration

ABSTRACT Low-cost green ceramic hollow fiber membranes (CHFM) were successfully designed and fabricated from the industrial waste ash, palm oil fuel ash (POFA) via phase inversion-based extrusion/sintering techniques for water filtration application. The extrusion process parameters such as suspension viscosity, air gap distance, and bore fluid flow rate were systematically explored to produce the membrane with desired morphology. A high suspension viscosity would result in a small macro-voids structure. Moreover, a high air gap distance would induce fiber with long macro-voids structure, while a low bore fluid flow rate would lead to the formation of distorted lumen structure. The effect of sintering temperature toward CHFM was also studied and characterized. An increase in the sintering temperature improved the membrane bending strength, but also afflicted the flux performance due to lower porosity and higher tortuosity. The developed membranes achieved excellent bending strengths of >75 MPa at lower sintering temperatures than the alternative ceramic counterparts, due to the formation of the eutectic liquid during sintering. The relatively low sintering temperature of POFA-derived CHFMs could reduce the energy consumption and sintering duration, which could be more economically attractive than their ceramic counterparts, thus benefiting industrial users.

Impact of organosilanes modified superhydrophobic‐superoleophilic kaolin ceramic membrane on efficiency of oil recovery from produced water

AbstractBACKGROUNDNovel hybrid absorption coupled with membrane filtration technology is proposed for the recovery of oil from produced water. This study aims at developing a low cost superhydrophobic‐superoleophilic kaolin‐based hollow fiber ceramic membrane using phase inversion and sintering technique for the recovery of oil from synthetic produced water. The influence of different organosialanes, such as methyltriethoxysilane (MTES), octadecyltrimethoxysilane (OTMS), 1H,1H,2H,2H‐perfluorooctyltriethoxysilane (FAS), trichloro(octadecyl)silane, and chlorotrimethylsilane, was investigated for the modification process.RESULTSField emission scanning electron microscopy results clearly indicated that membrane morphology was altered with coating of the organosilanes. The surface functionality of the organosilanes on kaolin membranes was also confirmed by X‐ray photoelectron spectroscopy and Fourier‐transform infrared spectroscopy. From the atomic force microscopy studies, membrane surface roughness was observed to be higher for MTES, FAS, and OTMS coated kaolin membranes. Contact analysis show that the membranes coated with MTES, FAS and OTMS organosilane agents possessed superhydrophobicity of 161.3°, 155.6°, and 150.2° as well as superoleophilicity of 0°, 1.5°, and 2.3°, respectively.CONCLUSIONCrude oil with a concentration of 2 g L−1 displayed a higher oil flux of 80 L m−2h−1 and absorption of 90% for MTES coated kaolin membrane. This study extends the frontier of knowledge in ceramic membrane application for produced water treatment. © 2020 Society of Chemical Industry (SCI)

Removal of aqueous organic contaminants using submerged ceramic hollow fiber membrane coupled with peroxymonosulfate oxidation: Comparison of CuO catalyst dispersed in the feed water and immobilized on the membrane

CuO catalyst dispersed in the feed water (CDF) and CuO catalyst immobilized on the ceramic hollow fiber membrane (CIM) for peroxymonosulfate (PMS) activation were developed and employed in the submerged membrane filtration systems for drinking water treatment, respectively. The performance of the CDF and CIM systems was systematically investigated and compared. The result indicated that BPA concentration, PMS dosage and CuO content exerted much less influence on BPA degradation in the CIM system as compared with that in the CDF system. The CIM system exhibited a greater advantage in the performance of BPA degradation and TOC removal when treating a large volume of feed (>300 mL). In addition, the effect of actual water matrix on the two systems was evaluated. The CIM system showed higher resistance to the adverse influence and better anti-fouling performance than the CDF system. The comparative study on the performance of CDF and CIM systems provides meaningful information for developing the process of membrane filtration coupled with PMS oxidation.

Innovative Rough Beer Conditioning Process Free from Diatomaceous Earth and Polyvinylpolypyrrolidone.

In large-sized breweries, rough beer clarification is still carried out using Kieselguhr filters notwithstanding their environmental and safety implications. The main aim of this work was to test an innovative rough beer clarification and stabilization process involving enzymatic treating with Brewers Clarex®, centrifuging, rough filtering across 1.4-μm ceramic hollow-fiber membrane at 30 °C, and fine filtering through 0.45-μm cartridge filter. When feeding an enzymatically-pretreated and centrifuged rough beer with permanent haze (HP) of 2 or 14 European Brewery Convention unit (EBC-U), its primary clarification under periodic CO2 backflushing yielded a permeate with turbidity of 1.0–1.5 EBC-U at a high permeation flux (2.173 ± 51 or 593 ± 100 L m−2 h−1), much greater than that typical of powder filters. The final beer was brilliant (HP = 0.57 ± 0.08 EBC-U) with almost the same colloidal stability of the industrial control and an overall log reduction value (~5.0 for the selected beer spoilage bacterium or 7.6 for the brewing yeast) in line with the microbial effectiveness of current sterilizing membranes. It was perceived as significantly different in flavor and body from the industrial control at a probability level of 10% by a triangle sensory test, as more likely related to the several lab-scale beer-racking steps used than to the novel process itself.

Facile Approach in Development of Superhydrophobic-Superoleophilic Kaolin-Based Hollow Fibre Ceramic Membrane

A silane coupling agent is an organosilicon compound with special structure possessing organic functional groups and hydrolysable groups. In this study, a superhydrophobic-superoleophilic nano-silica film on ceramic membrane was constructed by a modified Stöber technique by using tetraethoxy-silane (TEOS) and fluoroalkyl silane (FAS). The colloidal nano-silica based silane sol coating solution was synthesized via co-hydrolysis and co-condensation of TEOS and FAS. Particle size distribution of the colloidal nano-silica based silane sol was evaluated using particle size analyzer as depicted. The contents of the relative elements of the colloidal nano-silica based silane sol were examined using energy dispersive x-ray (EDX) spectra. Extent of superhydrophobicity-superoleophilicity was determined using the contact angle measurements. The surface wettability of superhydrophobicity-superoleophilicity was determined using the contact angle measurements. Also, the effects of grafting times and coating cycles on the wettability of the modified kaolin-based hollow fiber membrane were determined. The results revealed that the modified kaolin-based hollow fiber membrane exhibited oil contact of 0o and water contact angle of 160o and, demonstrating its considerable antiwetting applications like in oil-water filtration process. While, with an increase in grafting times and coating cycles, the wettability of the superhydrophobic-superoleophilic nano-silica film was enhanced due to increase in surface roughness provided by the hydrolysable groups on the surface of the ceramic membrane. In conclusion, this study presents a feasible route to the surface superhydrophobicity-superoleophilicity testing of ceramic membranes

Sacrificial graphene oxide interlayer for highly permeable ceramic thin film composite membranes

In this study, we report a facile and straightforward graphene oxide pre-coating method to prepare defect-free, ultrathin film composite ceramic hollow fiber membranes. By coating a graphene oxide (GO) interlayer, the defect-free thin alumina active layer with sub-micrometer thicknesses was successfully coated on highly porous substrates without thick interlayers. The GO interlayer not only prevents the pore-clogging of the substrate by boehmite nanoparticles but also helps the thin and uniform formation of active layers. Since the ultrathin GO interlayer was naturally removed during the calcination process of the active layer over 400 °C, the ceramic thin-film composite (TFC) membranes with controllable active layer thickness and pore size were obtained. Prepared ceramic TFC membranes showed outstanding separation performance, which was 2–8 times higher water flux at the same MWCO, compared to commercial multilayered ceramic ultrafiltration membranes. The results demonstrate the superior separation properties of ceramic TFC membranes, and the potential of cost-effective GO interlayer pre-coating methods for fabricating inorganic based membranes for various molecular separation applications.

CH4/CO2 separation from biogas stream using porous hydrophobic ceramic hollow fiber membrane contactors

Experiments were performed to separate CO2 from biogas using a ceramic hollow fiber membrane contactor (HFMC). CH4/CO2 mixed gas (34.5% CO2, CH4 balance) and monoethanolamine (MEA) were used. The influence of operating conditions, such as the gas flow rate, liquid flow rate, L/G ratio, CO2 partial pressure, and module type, on the CO2 removal efficiency and CO2 absorption flux was evaluated. As the gas flow rate increased, the CO2 removal efficiency decreased, while the CO2 absorption flux increased. The maximum CO2 removal efficiency was 96% at a gas flow rate of 0.1Nm3 h−1 while the maximum CO2 absorption flux was 7.5×10−3 mol·m−2·s−1 at a gas flow rate of 1Nm3 h−1. Moreover, the CO2 absorption flux and CO2 removal efficiency could be increased by more than 20% using the high-flux module.

Nitric oxide reduction by hydrogen peroxide absorption through a ceramic hollow fiber membrane contactor

Nitric oxide reduction by hydrogen peroxide absorption through a ceramic hollow fiber membrane contactor was studied experimentally. A membrane contactor with a single ceramic hollow fiber was characterized by multiple techniques, including contact angle measurement, gas permeation, water permeation and spectroscopy. The superhydrophobic ceramic was first used to achieve nonwetting conditions, and overatmospheric operating conditions were applied to enhance mass transfer. The effects of the process parameters on NO reduction were tested and discussed. It was found that NO reduction increases linearly with diffusion length. The gas flow rate and absorbent flow rate are suggested to be low to achieve high-efficiency gas absorption. NO reduction increases linearly with the enhancement factor or the square root of hydrogen peroxide concentration. Elevated pressure increases NO absorption flux and helps NO reduction within the breakthrough pressure.

Fabrication of magnesium bentonite hollow fibre ceramic membrane for oil-water separation

In this study, low-cost magnesium bentonite (MB) was used for the fabrication of bentonite hollow fibre (BHF) membrane with high pure water flux. MB powder was initially characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), particle size distribution (PSD) analyser, Brunnauer -Emmett- Teller (BET) method, and field emission scanning electron microscope (FESEM). The BHF membrane obtained was then fabricated through dope suspension mixing, phase inversion and sintering process. The dope suspension was prepared by mixing MB, dispersant, polymer binder, and solvent using a planetary ball mill. While the spinning process was carried out at the extrusion rate of 8 mL/min, a fluid bore rate of 10 mL/min and air gap of 5 cm, and this was followed by sintering operation at 950 °C, 1000 °C, 1050 °C, and 1100 °C. The resulting BHF membrane was characterized by scanning electron microscopy (SEM) and XRD; the porosity test, water flux and oil rejection were also examined. The SEM surface morphology of BHF at sintering temperature of 950 °C showed spongy-like and nested macrovoids structure; the porosity was 49.09% with a mean pore size of 3.9 µm. The performance test on the bentonite-based hollow fibre membrane showed that the membrane prepared at 20 wt% and sintering temperature of 1000 °C, which induced high and stable permeate water flux and oil rejection of BHFC membrane were 544 L/m2 h and 97%, respectively. The results have shown that the presence of magnesium in bentonite can enhance and promote the needed support material for the fabrication of hollow fibre ceramic membrane.

Rational design of ceramic hollow fibre catalyst, a new option for efficient removal of organic pollutants

Metallic catalysts have presented high activity for the degradation of pollutants. However, the inevitable metal leaching would lead to secondary pollution, which hinders the development of metallic catalysts for water treatment. Membrane technology would be an effective way to conquer this, especially hollow fibre membrane with numerous micro-pores and high surface area per unit volume. The good recoverability and stable repeatability proved that the ceramic hollow fibre membrane would be a promising form of metallic catalysts for aqueous phase reaction.

Integrated process for membrane fouling mitigation and organic pollutants removal using copper oxide modified ceramic hollow fiber membrane with in-situ peroxymonosulfate activation

A novel CuO modified ceramic hollow fiber membrane for in-situ peroxymonosulfate (PMS) activation was developed and employed in surface water treatment. The performance of membrane fouling control and organic pollutants removal was systematically investigated. The results indicated that compared with pristine membrane, CuO modified ceramic hollow fiber membrane significantly improved the removal of dissolved organic carbon (DOC) and UV absorbance at 254 nm (UV254) in surface water. The removal rate increased with the increase of CuO loading content because of the reduction of the membrane surface pore size, but declined with the increase of PMS dosage due to the degradation products of incomplete mineralization passing through the membrane. The fluorescent compounds in surface water were efficiently removed by the CuO modified ceramic hollow fiber membrane and enhanced with the increase of PMS dosage and CuO loading content. The CuO modified ceramic hollow fiber membrane with in-situ PMS activation exhibits excellent antifouling property to natural organic matter (NOM) in surface water. Both the reversible and irreversible fouling decreased with the increase of PMS dosage while the membrane fouling would be slightly intensified with increased loading of CuO on the membrane, suggesting the trade-off relation between PMS dosage and CuO loading content. In addition, the degradation efficiency of organic pollutants in surface water was dramatically enhanced by the CuO modified ceramic hollow fiber membrane via incorporation of in-situ PMS oxidation process. High removal performance after five cycles of experiments showed the superior stability and reusability of the CuO modified ceramic hollow fiber membrane.

Comparative study of Malaysian and Nigerian kaolin-based ceramic hollow fiber membranes for filtration application

Ceramic membrane has gained increasing interest in water filtration application due to its inherent characteristics. Low-cost clay materials are preferred to fabricate an efficient and cost-effective ceramic membrane. Among the ceramics, kaolin displays better mechanical, thermal, and chemical properties. However, natural properties of kaolin vary from different studies. Hence, cost-effective Nigeria (NK) and Malaysia (MK) kaolins were compared to study the fabrication of kaolin hollow fiber ceramic membrane for filtration application. The effects of kaolin loading concentration (34 and 37 wt. %) and sintering temperature (1200, 1350, 1400, and 1500 °C) on kaolin membrane fabrication were also studied. XRF studies indicated that the hydroxyl silica and alumina compositions were 56.76wt.% and 41.97wt% for NK and 55.21wt.% and 40.33wt% for MK. MK exhibited intense kaolinite peak with a broad range of particle size distribution. The mechanical stability of kaolin ceramic membrane increased with the increase of sintering temperature and kaolin loading concentration. Membrane morphology also varied with MK and NK. Interestingly, 34wt% kaolin at a sintered temperature of 1350 °C produced ceramic membrane with a high water flux. A similar trend was observed in both MK and NK, where the flux of 34wt% MK and NK are 565 and 460 L/m2h, respectively.

Influence of the Natural Zeolite Particle Size Toward the Ammonia Adsorption Activity in Ceramic Hollow Fiber Membrane.

Natural zeolite is widely used in removing ammonia via adsorption process because of its superior ion-exchange properties. Ceramic particle size affects the adsorptivity of particles toward ammonia. In this study, hollow fiber ceramic membrane (HFCM) was fabricated from natural zeolite via phase inversion. The effect of natural zeolite particle size toward the properties and performance of HFCM was evaluated. The results show that the HFCM with smaller particle sizes exhibited a more compact morphological structure with better mechanical strength. The adsorption performance of HFCM was significantly improved with smaller particle sizes because of longer residence time, as proven by the lower water permeability. A high adsorption performance of 96.67% was achieved for HFCM with the smallest particle size (36 μm). These findings provide a new perspective on the promising properties of the natural zeolite-derived HFCM for ammonia removal.

Tailor-Made Zeolitic Water Nanochannels for Liquid Fuel Production

Conversion of CO2 into valuable liquid fuels or other chemicals has been one of the attractive ways for effective utilization of CO2 produced by burning fossil fuels. However, this task is challenging due to the difficulties associated with the chemical inertness of CO2. In addition to research efforts devoted to the development of more active and selective catalysts for CO2 hydrogenation reaction, removing the by-product water from the system is proven beneficial for improving the reaction thermodynamics and kinetics toward desirable products. Therefore, highly water-selective membranes able to operate under reaction conditions like high temperature and pressure have long been pursued. In a recent study, Yu et al. reported a zeolite membrane with gas-impeding water-conduction nanochannels that selectively remove by-product water from CO2 dehydrogenation process, greatly enhancing CO2 conversion and methanol yield.

Structural Characterisation of Deposit Layer during Milk Protein Microfiltration by Means of In-Situ MRI and Compositional Analysis.

Milk protein fractionation by microfiltration membranes is an established but still growing field in dairy technology. Even under cross-flow conditions, this filtration process is impaired by the formation of a deposit by the retained protein fraction, mainly casein micelles. Due to deposition formation and consequently increased overall filtration resistance, the mass flow of the smaller whey protein fraction declines within the first few minutes of filtration. Currently, there are only a handful of analytical techniques available for the direct observation of deposit formation with opaque feed media and membranes. Here, we report on the ongoing development of a non-invasive and non-destructive method based on magnetic resonance imaging (MRI), and its application to characterise deposit layer formation during milk protein fractionation in ceramic hollow fibre membranes as a function of filtration pressure and temperature, temporally and spatially resolved. In addition, the chemical composition of the deposit was analysed by reversed phase high pressure liquid chromatography (RP-HPLC). We correlate the structural information gained by in-situ MRI with the protein amount and composition of the deposit layer obtained by RP-HPLC. We show that the combination of in-situ MRI and chemical analysis by RP-HPLC has the potential to allow for a better scientific understanding of the pressure and temperature dependence of deposit layer formation.

Effects of pre and post-ozonation on POFA hollow fibre ceramic adsorptive membrane for arsenic removal in water

This study examined the use of modified palm oil fuel ash (POFA) prepared from agricultural waste as key material for fabricating the POFA hollow fibre ceramic membrane (PHFCM) to trap arsenite, As(III), and arsenate, As(V), from water. In this study, the ozonation technique was employed where the effects of pre- and post-ozonation on the adsorption capacity of PHFCM and fouling mitigation were investigated respectively. The highest sintering temperature of 1150 °C (PHFCM-11500) delivered maximum adsorption capacities that corresponded to 95.62 and 98.34 mg·g−1 of As(III) and As(V). PHFCM-1150 with sufficient mechanical strength (52.84 MPa) and excellent pure water flux (250.73 L/m2.h) were selected for further exploration with ozonation study. Pre-ozonation increased the adsorption performance while the fouling problem of PHFCM was successfully treated by post-ozonation. Additionally, the post-ozonation treatment offers a cost-effective application of PHFCM-1150 with only 3 min of optimum reaction time that enables the integrated reuse of the sorbent, with the practical and effective removal of As for industrial effluent/wastewater treatment. This study also demonstrated that PHFCM-1150 was effective and its respective As removal met the maximum discharge limit of 10 μg/L set by the World Health Organization and the national legislation in Malaysia.

Integrated membrane contactor absorber/regeneration column process for CO2 capture with large scale module at various operating conditions

In this study, a 3-in. diameter ceramic hollow fiber membrane contactor unit module with an improved flow path was successfully developed for CO2 capture. The effect of CO2 loading in the absorbent, water and oxygen in the flue gas was evaluated in order to evaluate the performance of the ceramic hollow fiber membrane module. No performance degradation was found for water vapor and oxygen in the flue gas. On the other hand, absorption performance decreased with the amount of CO2 loaded in the absorbent. The 2-stage module was able to absorb more than 90 % of CO2 in 0.5 Nm3/h flue gas with 0.17 mol CO2/mol MEA loaded absorbent. At this time, the gas and liquid pressure drops were 0.012 and 0.010 bar, respectively. This is a small value compared to the pressure drop of the conventional packed absorption column process. In addition, the integrated membrane absorber/stripping column process was operated for more than 60 h and the CO2 removal efficiency was maintained at about 84 %. There was no decrease in performance or pore swelling of the membrane. Ceramic hollow fiber membrane contactor is a promising process that can replace conventional absorption process or polymeric membrane contactor.