scholarly journals Parametrization Study of Electrospun Nanofiber Including LiCl Using Response Surface Methodology (RSM) for Water Treatment Application

2020 ◽  
Vol 10 (20) ◽  
pp. 7295
Author(s):  
Jiyeol Bae ◽  
Hyuna Kim ◽  
Saerom Park ◽  
Kwang Soo Kim ◽  
Heechul Choi

The influence of the electrospinning parameters on the diameter of the polyethersulfone (PES) nanofibers was demonstrated using response surface methodology. The electrospinning parameters studied were lithium chloride (LiCl) concentration, PES concentration, feed rate, and tip-to-collector distance. The average fiber diameter was correlated to these factors by using a second-order polynomial function at a 95% confidence level. The statistical analysis indicated that LiCl concentration, PES concentration, and feed rate had the significant connection with the fiber diameter, and LiCl concentration was the most important factor in determining the fiber diameter. When LiCl concentration increased, the fiber diameter decreased, because with more LiCl that is added, more applied voltage is needed to overcome the electrostatic attractions. The interactive effect between PES concentration and feed rate, the interactive effect between PES concentration and tip-to-collector distance, and the quadratic coefficients of LiCl concentration were also found to be significant. The adjusted determination coefficient (Radj2) of the model was calculated to be 0.9106. The water flux measurements showed that the decrease in the fiber diameter of the membrane caused the decrease in the initial pure water flux. The retention tests with 0.6 μm polystyrene (PS) suspension indicated that as the fiber diameter decreased, the pore sizes decreased and the particle removal efficiency increased.

2021 ◽  
Vol 02 (01) ◽  
Author(s):  
Mohd Riduan Jamalludin ◽  
◽  
Siti Khadijah Hubadillah ◽  
Zawati Harun ◽  
Muhamad Zaini Yunos ◽  
...  

This study investigates the effects of rice husk silica (RHS) as additive in the polysulfone membrane to enhance antifouling properties in membrane separation process. The performance (of what?) was evaluated in term of pure water flux (PWF), rejection and antifouling properties. The optimized of normalized flux (Jf /Jo) at different parameter in filtration (pH, ionic strength and tranmembrane-pressure) was carried out by using the response surface methodology (RSM). The results showed that the addition of 4 wt. % RHS give the highest flux at 300.50 L/m².hour (LMH). The highest rejection was found at 3 wt. % of RHS membrane with value 98% for UV254 and 96% for TOC. The optimal value of Jf/Jo was found at 0.62 with the condition of pH: 6.10, ionic strength: 0.05 mol/L and transmembrane-pressure: 2.67 bars. Optimize of RSM analysis from ANOVA also proved that the error of model is less than 0.05% which indicates that the model is significant.


1999 ◽  
Vol 40 (9) ◽  
pp. 113-120 ◽  
Author(s):  
A. Maartens ◽  
P. Swart ◽  
E. P. Jacobs

Organic matter in natural brown water as well as humic acids from a commercial sample were characterised by ultraviolet-visible light-spectroscopy and used in ultrafiltration studies. During ultrafiltration the pure-water flux and the operational flux were measured continuously to determine the degree of membrane fouling. The natural organic matter and commercial humic acid concentrations of the feed and permeate solutions were determined spectrophotometrically. These variables were used in conjunction with conventional flux measurements, to determine the colour-removal efficiency of ultrafiltration as well as the degree of foulant adsorption onto the membranes. Fouled membranes were cleaned with alkaline chemical agents normally used to extract natural organic matter from soil samples. The cleaning efficiency and the effect of cleaning solutions on the membrane selectivity were studied.


2011 ◽  
Vol 480-481 ◽  
pp. 201-206
Author(s):  
Li Guo Wang ◽  
Xiu Ju Wang ◽  
Ai Min Wang ◽  
Wen Juan Liu ◽  
Shi Qi Guo ◽  
...  

Hydrophilic Polyvinylidene fluoride (PVDF) hollow fiber ultrafiltration membranes were prepared by wet-spinning method. The effects of technical parameters of acrylic acid grafted onto PVDF on the performance of hydrophilic PVDF membranes were investigated via orthogonal test, the technical parameters of preparation of hydrophilic PVDF membranes were determined, and hydrophilic PVDF membranes were prepared. Then hydrophilic PVDF membranes were characterized in terms of breaking strength, breaking elongation, rupture pressure, pure water flux and rejection. The fouling properties and the conditions of acrylic acid grafted onto PVDF were also examined. The results showed that acrylic acid had been grafted onto PVDF, the breaking strength and rupture pressure improved greatly, and the fouling properties were better than PS hollow fiber UF membrane.


2017 ◽  
Vol 76 (4) ◽  
pp. 776-784 ◽  
Author(s):  
Mijia Zhu ◽  
Jun Yao ◽  
Zhonghai Qin ◽  
Luning Lian ◽  
Chi Zhang

Wastewater produced from polymer flooding in oil production features high viscosity and chemical oxygen demand because of the residue of high-concentration polymer hydrolysed polyacrylamide (HPAM). In this study, steel slag, a waste from steel manufacturing, was studied as a low-cost adsorbent for HPAM in wastewater. Optimisation of HPAM adsorption by steel slag was performed with a central composite design under response surface methodology (RSM). Results showed that the maximum removal efficiency of 89.31% was obtained at an adsorbent dosage of 105.2 g/L, contact time of 95.4 min and pH of 5.6. These data were strongly correlated with the experimental values of the RSM model. Single and interactive effect analysis showed that HPAM removal efficiency increased with increasing adsorbent dosage and contact time. Efficiency increased when pH was increased from 2.6 to 5.6 and subsequently decreased from 5.6 to 9.3. It was observed that removal efficiency significantly increased (from 0% to 86.1%) at the initial stage (from 0 min to 60 min) and increased gradually after 60 min with an adsorbent dosage of 105.2 g/L, pH of 5.6. The adsorption kinetics was well correlated with the pseudo-second-order equation. Removal of HPAM from the studied water samples indicated that steel slag can be utilised for the pre-treatment of polymer-flooding wastewater.


2017 ◽  
Vol 79 (1-2) ◽  
Author(s):  
Siti Khadijah Hubadillah ◽  
Mohd Hafiz Dzarfan Othman ◽  
A. F. Ismail ◽  
Mukhlis A. Rahman ◽  
Juhana Jaafar

Ceramic hollow fibre membrane (CHFM) demonstrated superior characteristics and performance in any separation application. The only problem associated with this kind of technology is the high cost. In order to effectively fabricate and produce low cost porous CHFM, a series of CHFMs made of kaolin were fabricated via combined phase inversion and sintering technique. The CHFMs from kaolin named as kaolin hollow fibre membranes (KHFMs) were studied at different kaolin contents of 35 wt.%, 37.5 wt.% and 40 wt.% sintered at 1200ºC. The result indicated that by varying kaolin contents, different morphologies were obtained due to changes in the viscosity of ceramic suspension containing kaolin. The optimum kaolin content for KHFM was identified. It was found that KHFM prepared at 37.5 wt% has a mechanical strength and pure water flux of A and B respectively.  


2014 ◽  
Vol 931-932 ◽  
pp. 168-172 ◽  
Author(s):  
Asmadi Ali ◽  
Mohamad Awang ◽  
Ramli Mat ◽  
Anwar Johari ◽  
Mohd Johari Kamaruddin ◽  
...  

It is well known that membrane with hydrophobic property is a fouling membrane. Polysulfone (PSf) membrane has hydrophobic characteristic was blended with a hydrophilic polymer, cellulose acetate phthalate (CAP) in order to increase hydrophilicity property of pure PSf membrane. In this study, membrane casting solutions containing 17 wt% of polymer was prepared via wet phase inversion process. The pure PSf membrane was coded as PC-0. PSf/CAP blend membranes with blend composition of 95/5, 90/10, 85/15 and 80/20 wt% of total polymer concentration in the membrane casting solutions were marked as PC-5, PC-10, PC-15 and PC-20 respectively. All of the membranes were characterized in terms of pure water flux and permeability coefficient in order to study their hydrophilicity properties. The investigated results shows that increased of CAP composition in PSf blend membranes has increased pure water flux, permeability coefficient and porosity of the blend membrane which in turn formed membrane with anti-fouling property.


2020 ◽  
Author(s):  
Zaber Ahmed ◽  
Mohd Suffian Yusoff ◽  
Nurul Hana Mokhtar Kamal ◽  
Hamidi Abdul Aziz

Abstract Malaysia is the 2nd largest in palm oil export, and after overcoming economic age (average 25 years), the palm oil trees entail to replace usually. Therefore, a massive quantity of palm oil trunk biomass, containing a significant amount of starch, is available as bio-waste annually. The efficient extraction of this starch (carbohydrate polymer) would be worthwhile concerning the environment, economy, conversion of biowaste to bioresources, and waste dumping challenges. Central composite design executed an experimental model design, evaluated the impacts of process variables and their interaction through response surface methodology to optimize the novel bisulfite steeping method for starch synthesis. Design-Expert software performed the data analysis. The developed quadratic models for four factors (Strength of Sodium bisulfite solution, steeping hour, mixing ratio with the bisulfite solution and ultra-pure water) and one response (%Yield), demonstrated that a significant starch yield (13.54%) is achievable utilizing 0.74% bisulfite solution, 5.6 steeping hours, for 1.6 and 0.6 mixing ratio with the bisulfite solution and ultra-pure water respectively. Experimental outcomes were quite consistent with the predicted model, which eventually sustains the significance of this method. Malvern Zetasizer test revealed a bimodal granular distribution for starch, with 7.15µm of hydrodynamic size. Starch morphology was determined by scanning electron microscopy. X-ray diffraction investigation exhibits an A-type model, specifying persistent characteristics of extracted starch.


2018 ◽  
Vol 18 (1) ◽  
pp. 1
Author(s):  
Romaya Sitha Silitonga ◽  
Nurul Widiastuti ◽  
Juhana Jaafar ◽  
Ahmad Fauzi Ismail ◽  
Muhammad Nidzhom Zainol Abidin ◽  
...  

Poly(vinylidene fluoride) (PVDF) has outstanding properties such as high thermal stability, resistance to acid solvents and good mechanical strength. Due to its properties, PVDF is widely used as a membrane matrix. However, PVDF membrane is hydrophobic properties, so as for specific applications, the surface of membrane needs to be modified to become hydrophilic. This research aims to modify PVDF membrane surface with chitosan and glutaraldehyde as a crosslinker agent. The FTIR spectra showed that the modified membrane has a peak at 1655 cm-1, indicating the imine group (–N=C)- that was formed due to the crosslink between amine group from chitosan and aldehyde group from glutaraldehyde. Results showed that the contact angle of the modified membrane decreases to 77.22° indicated that the membrane hydrophilic properties (< 90°) were enhanced. Prior to the modification, the contact angle of the PVDF membrane was 90.24°, which shows hydrophobic properties (> 90°). The results of porosity, Ɛ (%) for unmodified PVDF membrane was 55.39%, while the modified PVDF membrane has a porosity of 81.99%. Similarly, by modifying the PVDF membrane, pure water flux increased from 0.9867 L/m2h to 1.1253 L/m2h. The enhancement of porosity and pure water flux for the modified PVDF membrane was due to the improved surface hydrophilicity of PVDF membrane.


Membranes ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 703
Author(s):  
Yi Ding ◽  
Zhansheng Guo ◽  
Xinan Dong ◽  
Hong You ◽  
Junxue Mei ◽  
...  

Based on carboxylated multi-walled carbon nanotubes (MWCNTs-COOH), a MWCNTs/PVDF conductive membrane was prepared by a vacuum filtration cross-linking method. The surface compositions and morphology of conductive membranes were studied by X-ray photoelectron spectroscopy and high-resolution field emission scanning electron microscopy, respectively. The effects of cross-linked polymeric polyvinyl alcohol (PVA) on the conductive membrane properties such as the porosity, pore size distribution, pure water flux, conductivity, hydrophilicity, stability and antifouling properties were investigated. Results showed that the addition of PVA to the MWCNTs/PVDF conductive membrane decreased the pure water flux, porosity and the conductivity. However, the hydrophilicity of the modified MWCNTs/PVDF conductive membrane was greatly improved, and the contact angle of pure water was reduced from 70.18° to 25.48° with the addition of PVA contents from 0 wt% to 0.05 wt%. Meanwhile, the conductive membranes with higher content had a relatively higher stability. It was found that the conductive functional layer of the conductive membrane had an average mass loss rate of 1.22% in the 30 min ultrasonic oscillation experiment. The tensile intensity and break elongation ratio of the conductive membrane are improved by the addition of PVA, and the durability of the conductive membrane with PVA was superior to that without PVA added. The electric assisted anti-fouling experiments of modified conductive membrane indicated that compared with the condition without electric field, the average flux attenuation of the conductive membrane was reduced by 11.2%, and the membrane flux recovery rate reached 97.05%. Moreover, the addition of PVA could accelerate the clean of the conductive membranes.


Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 393
Author(s):  
Tanzila Anjum ◽  
Rahma Tamime ◽  
Asim Laeeq Khan

High-performance Mixed-Matrix Membranes (MMMs) comprising of two kinds of porous fillers UiO-66 and Zeolite 4Aand their combination were fabricated with polysulfone (PSf) polymer matrix. For the very first time, UiO-66 and Zeolite 4A were jointly used as nanofillers in MMMs with the objective of complimenting synergistic effects. The individual and complimentary effects of nanofillers were investigated on membrane morphology and performance, pure water flux, humic acid rejection, static humic acid adsorption, and antifouling properties of membranes. Scanning Electron Microscopy (SEM) analysis of membranes confirmed that all MMMs possessed wider macrovoids with higher nanofiller loadings than neat PSf membranes and the MMMs (PSf/UiO-66 and PSf/Zeolite 4A-UiO-66) showed tendency of agglomeration with high nanofiller loadings (1 wt% and 2 wt%). All MMMs exhibited better hydrophilicity and lower static humic acid adsorption than neat PSf membranes. Pure water flux of MMMs was higher than neat PSf membranes but the tradeoff between permeability and selectivity was witnessed in the MMMs with single nanofiller. However, MMMs with combined nanofillers (PSf/Zeolite 4A-UiO-66) showed no such tradeoff, and an increase in both permeability and selectivity was achieved. All MMMs with lower nanofiller loadings (0.5 wt% and 1 wt%) showed improved flux recovery. PSf/Zeolite 4A-UiO-66 (0.5 wt%) membranes showed the superior antifouling properties without sacrificing permeability and selectivity.


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