Polysulfone Activated Carbon Composite Membranes

2010 ◽  
Vol 660-661 ◽  
pp. 1081-1086 ◽  
Author(s):  
Priscila Anadão ◽  
Laís Fumie Sato ◽  
Hélio Wiebeck ◽  
Francisco Rolando Valenzuela-Díaz

The addition of a fourth component in the system composed by polymer/ solvent/ non-solvent is a technique generally employed to enhance membrane properties. Since polysulfone presents low hydrophilicity, which can hamper filtration performance, the addition of a hydrophilic material can be an important technique to improve this property. Therefore, the main purpose of this work is to understand the influence of addition of the activated carbon in the system polysulfone/ NMP/ water in terms of membrane morphology, hydrophilicity, thermal and mechanical resistance. From scanning electron micrographs, it could be seen that membrane surface became denser with the addition of higher activated carbon contents and the cross-section morphology was not changed. Acid-base interactions were favored with the activated carbon addition and the availability of Lifshtiz-van Der Waals interactions was decreased, being these two properties very important to avoid fouling formation onto membrane surface. The glass transition temperatures of the polysulfone composite membranes with higher activated carbon contents were increased. However, all activated carbon contents brittled the composite membranes in relation to the pristine polysulfone membrane.

2017 ◽  
Vol 54 (2) ◽  
pp. 257-261 ◽  
Author(s):  
Stefan Catalin Pintilie ◽  
Laurentia Geanina Tiron ◽  
Iulian Gabriel Birsan ◽  
Daniel Ganea ◽  
Stefan Balta

The activity of using membrane technology has developed fast in the treatment of wastewater, drinking water and process water production. The main challenges in membrane filtration are fouling reduction, permeability increase and high efficiency in retention. The best example of membrane enhancement is increasing hydrophilicity. Nanoparticles have been proven that their presence in the membrane matrix increases the water affinity significantly. Although the zinc oxide nanoparticles have a positive effect over the membrane performance, the influence of zinc oxide (ZnO) nanoparticle size has not been studied enough. Two sizes of nanoparticle of ZnO and three concentrations were used for the preparation of composite polysulfone ultrafiltration membranes. The effects of the ZnO nanoparticles in the membrane matrix on the permeation properties, flux stability and retention were tested. SEM, EDX, porosity and contact angle measurement were conducted in this article, also. The experimental results indicated that ZnO-PSf composite membranes exhibits significant differences in the membrane properties due to nanoparticle addition and regardless of their size it leads to an increase in hydrophilicity, flux, permeability, retention and porosity. Decreasing the nanoparticle size leads to an increase in membrane performance.


2017 ◽  
Vol 68 (2) ◽  
pp. 203-209
Author(s):  
Hussam Nadum Abdalraheem Al Ani ◽  
Anca Maria Cimbru ◽  
Corneliu Trisca-Rusu ◽  
Szidonia Katalin Tanczos ◽  
Adriana Cuciureanu ◽  
...  

This paper illustrates the possibility of producing iono-molecular separations using ionic colloidal ultrafiltration membrane of polysulfone synthetic solutions of cupric ions and nitro phenols through ultrafiltration assisted by polymeric nanoparticle composites based on polysulfone. In the present work, in order to reduce the operating pressure and increase the flow of water we are using the process of ultrafiltration through a polysulfone membrane in N-methylpyrrolidone 10% prepared by coagulation in isopropanol. The nanoparticles needed in colloidal ultrafiltration had been obtained through the immersion technique of precipitation of a solution of 5% PSf in N-methyl pyrrolidone containing 3% aniline in lower alcohols: methanol, ethanol, and isopropanol, followed by the oxidation of the remaining aniline in a solution of 10% hydrochloric acid and ammonium persulfate. The Nanoparticles of polysulfone (NP-PSf) and The three obtained variants of nanoparticles composites (NP-PSf-PANI) were morphologically (SEM) and (AFM), structurally and compositionally (FTIR) characterized and the results show that nanoparticles polysulfone have a much lower range than the composites. The Possibility of copper complexation by both nitrophenols, and by nanoparticle surface probably lead to the formation of more stable aggregates in the supply, which can sufficiently justify the increased retention. The Retentions of the chemical species in question use in all the tests made the same series:R NP-PSf-PANI-M] R NP-PSf-PANI-E] R NP-PSf-PANI-P] R NP-PSf


2005 ◽  
Vol 5 (5) ◽  
pp. 1-8 ◽  
Author(s):  
K.Y. Choi ◽  
B.A. Dempsey

The objective of the research was to evaluate in-line coagulation to improve performance during ultrafiltration (UF). In-line coagulation means use of coagulants without removal of coagulated solids prior to UF. Performance was evaluated by removal of contaminants (water quality) and by resistance to filtration and recovery of flux after hydraulic or chemical cleaning (water production). We hypothesized that coagulation conditions inappropriate for conventional treatment, in particular under-dosing conditions that produce particles that neither settle nor are removed in rapid sand filters, would be effective for in-line coagulation prior to UF. A variety of pre-treatment processes for UF have been investigated including coagulation, powdered activated carbon (PAC) or granular activated carbon (GAC), adsorption on iron oxides or other pre-formed settleable solid phases, or ozonation. Coagulation pre-treatment is often used for removal of fouling substances prior to NF or RO. It has been reported that effective conventional coagulation conditions produced larger particles and this reduced fouling during membrane filtration by reducing adsorption in membrane pores, increasing cake porosity, and increasing transport of foulants away from the membrane surface. However, aggregates produced under sweep floc conditions were more compressible than for charge neutralization conditions, resulting in compaction when the membrane filtration system was pressurized. It was known that the coagulated suspension under either charge-neutralization or sweep floc condition showed similar steady-state flux under the cross-flow microfiltration mode. Another report on the concept of critical floc size suggested that flocs need to reach a certain critical size before MF, otherwise membranes can be irreversibly clogged by the coagulant solids. The authors were motivated to study the effect of various coagulation conditions on the performance of a membrane filtration system.


Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1207
Author(s):  
Aled D. Roberts ◽  
Jet-Sing M. Lee ◽  
Adrián Magaz ◽  
Martin W. Smith ◽  
Michael Dennis ◽  
...  

Fabrics comprised of porous fibres could provide effective passive protection against chemical and biological (CB) threats whilst maintaining high air permeability (breathability). Here, we fabricate hierarchically porous fibres consisting of regenerated silk fibroin (RSF) and activated-carbon (AC) prepared through two fibre spinning techniques in combination with ice-templating—namely cryogenic solution blow spinning (Cryo-SBS) and cryogenic wet-spinning (Cryo-WS). The Cryo-WS RSF fibres had exceptionally small macropores (as low as 0.1 µm) and high specific surface areas (SSAs) of up to 79 m2·g−1. The incorporation of AC could further increase the SSA to 210 m2·g−1 (25 wt.% loading) whilst also increasing adsorption capacity for volatile organic compounds (VOCs).


Carbon ◽  
2021 ◽  
Author(s):  
Ziwen Yuan ◽  
Yanxi Yu ◽  
Xiao Sui ◽  
Yuanyuan Yao ◽  
Yuan Chen

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 380
Author(s):  
Yan Chen ◽  
Huiping Li ◽  
Weihai Pang ◽  
Baiqin Zhou ◽  
Tian Li ◽  
...  

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.


Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 859
Author(s):  
Yu Zang ◽  
Toshiki Aoki ◽  
Masahiro Teraguchi ◽  
Takashi Kaneko ◽  
Hongge Jia ◽  
...  

Two kinds of novel nanoporous polycondensates (sc(Rf)) have been synthesized by two new preparation methods consisting of polycondensation and highly selective photocyclicaromataization of 1/3 helical cis-cis polyphenylacetylenes with polymerizable groups. By the original methods, new well-defined sheet polymers having nanopores or nanospaces have been synthesized for the first time. Their composite membranes, containing small amounts (1.0 wt%) of sc(Rf), had ultrahigh oxygen permeability (Po2 > 1000 barrer), and their plots were beyond the Robeson’s upper bound line in the graph of oxygen permselectivity (α = Po2/PN2) versus Po2. Both α and Po2 values were enhanced by adding only small amounts (1.0 wt%) of sc(Rf). One of the sc(Rf)s synthesized on the base membrane surface showed the best performance, i.e., Po2 = 5300 barrer and α = 2.5. The membrane surface was effectively covered by sc(Rf), judging from the contact angle values. It is thought that nanopores and nanospaces created in and between sc(Rf) molecules played an important role for the enhancement of both α and Po2/PN2.


2015 ◽  
Vol 180 ◽  
pp. 22-28 ◽  
Author(s):  
Mohammed A. Ajeel ◽  
Mohamed Kheireddine Aroua ◽  
Wan Mohd Ashri Wan Daud

2020 ◽  
pp. 108128652097760
Author(s):  
Carlos Quesada ◽  
Claire Dupont ◽  
Pierre Villon ◽  
Anne-Virginie Salsac

A novel data-driven real-time procedure based on diffuse approximation is proposed to characterize the mechanical behavior of liquid-core microcapsules from their deformed shape and identify the mechanical properties of the submicron-thick membrane that protects the inner core through inverse analysis. The method first involves experimentally acquiring the deformed shape that a given microcapsule takes at steady state when it flows through a microfluidic microchannel of comparable cross-sectional size. From the mid-plane capsule profile, we deduce two characteristic geometric quantities that uniquely characterize the shape taken by the microcapsule under external hydrodynamic stresses. To identify the values of the unknown rigidity of the membrane and of the size of the capsule, we compare the geometric quantities with the values predicted numerically using a fluid-structure-interaction model by solving the three-dimensional capsule-flow interactions. The complete numerical data set is obtained off-line by systematically varying the governing parameters of the problem, i.e. the capsule-to-tube confinement ratio, and the capillary number, which is the ratio of the viscous to elastic forces. We show that diffuse approximation efficiently estimates the unknown mechanical resistance of the capsule membrane. We validate the data-driven procedure by applying it to the geometric and mechanical characterization of ovalbumin microcapsules (diameter of the order of a few tens of microns). As soon as the capsule is sufficiently deformed to exhibit a parachute shape at the rear, the capsule size and surface shear modulus are determined with an accuracy of 0.2% and 2.7%, respectively, as compared with 2–3% and 25% without it, in the best cases (Hu et al. Characterizing the membrane properties of capsules flowing in a square-section microfluidic channel: Effects of the membrane constitutive law. Phys Rev E 2013; 87(6): 063008). Diffuse approximation thus allows the capsule size and membrane elastic resistance to be provided quasi-instantly with very high precision. This opens interesting perspectives for industrial applications that require tight control of the capsule mechanical properties in order to secure their behavior when they transport active material.


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