scholarly journals The effect of Merpol surfactant on the morphology and performance of PES/PVP membranes: antibiotic separation

2019 ◽  
Vol 10 (4) ◽  
pp. 301-309
Author(s):  
Maryam Omidvar ◽  
Zahra Hejri ◽  
Ahmad Moarefian

Abstract The present study used modified nanofiltration (NF) membranes to remove the emerging contaminant of amoxicillin (AMX) from synthetic wastewater. For this purpose, Merpol surfactant and polyvinylpyrrolidone were added to the casting solutions to prepare flat sheet asymmetric polyethersulfone (PES) NF membranes through phase inversion process. Then, the effect of adding Merpol surfactant at different concentrations on the morphology, hydrophilicity, and pure water flux (PWF) of the membranes, as well as the separation of AMX from aqueous solutions was investigated. The characteristics of the prepared membranes were studied by scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), contact angle (CA) measurement and performance tests. The obtained results approved the improved hydrophilicity of the PES membranes after adding Merpol surfactant to the casting solution. The findings also revealed a gradual increase in the average size of the membrane pores in sub-layer and thinner top layer, proportional to the increase of surfactant content in the solution. The results also confirmed the increase of PWF under the influence of surfactant increase. As a result, for the membrane containing 8 wt% Merpol additive, the lowest CA (52.08°), the highest PWF (76.31 L/m2 h), and maximum AMX excretion (97%) were achieved.

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.  


2013 ◽  
Vol 65 (4) ◽  
Author(s):  
Law Yong Ng ◽  
Abdul Wahab Mohammad ◽  
Ching Yin Ng ◽  
Nur Hanis Hayati Hairom

In this research work, porous PES membranes were initially pre-heated for certain duration of time and then surface-modified to reject the MgSO4 salt solutions through self-adsorption of polyelectrolytes. From the experimental work, higher membrane salt rejection capability can be obtained when the number of polyelectrolyte bilayers is increased. The images of the cross-sectional morphology of modified and non-modified membranes were obtained using field emission scanning electron microscopy (FESEM). All modified membranes showed relatively lower contact angle values.


Zootaxa ◽  
2011 ◽  
Vol 2970 (1) ◽  
pp. 33 ◽  
Author(s):  
CLAUDIA M. SANDOVAL ◽  
ELSA NIEVES ◽  
VÍCTOR M. ANGULO ◽  
JOÃO ARISTEU DA ROSA ◽  
ELIS ALDANA

The external morphology of eggs of the species Belminus corredori Galvão & Angulo, 2006, Belminus herreri Lent & Wygodzinsky, 1979 and Belminus ferroae Sandoval, Pabón, Jurberg & Galvão, 2007 is described for the first time using scanning electron microscopy (SEM). Females lay one egg at a time; the shape of the egg is oval with lateral flattening, a rounded caudal area and a true and simple convex operculum. The average size of the egg among these species is 0.51– 0.58 mm in length and 0.36–0.4 mm in width. As a generic character we highlight the discovery of a chorion rim with one to four grooves always joined to the micropyles. All species present a clear polygonal pattern only in the operculum and in the egg’s cephalic region, while the median and caudal regions show a smooth appearance, features that are shared only with the eggs of the genus Alberprosenia. A discriminant analysis of the polygonal design of the operculum proved to be useful for the identification of the species.


2012 ◽  
Vol 535-537 ◽  
pp. 996-999 ◽  
Author(s):  
Bao Feng Zhang ◽  
Qi Chen ◽  
Xiao Wei Chen ◽  
Hong Liang Zhao

In this study, the effect of KBF4 addition on the microstructure of the Mg-6Zn-1Si alloy has been investigated by Optical Microscopy (OM), Scanning Electron Microscopy (SEM) with Energy Dispersive Spectrometer(EDS). At 1.5wt% KBF4 addition, the morphology of Mg2Si phase completely changed from Chinese script type into uniformly, dispersedly distributed graininess or small block, with the average size of the Mg-6Zn-1Si alloy decreasing from 135μm to 82μm.


2013 ◽  
Vol 457-458 ◽  
pp. 309-312 ◽  
Author(s):  
Yang Bai ◽  
Zhen Liu ◽  
Dao Bao Sun

Polysulfone (PSF) hollow fiber ultrafiltration membranes were successfully prepared by dry-wet spinning technology. Dimethylacetamide (DMAC) was used as a solvent, water was used as bore liquid and coagulation bath, polyvinylpyrrolidone (PVP) was used as polymeric additive. The effects of spinning conditions on membrane structures and properties were investigated in present study. The results indicated that with the increase of PVP concentration, pure water flux increased and developed finger-like pores were formed. High coagulation bath temperature restricted pure water flux, 30°C was the best for the preparation of high-performance ultrafiltration membranes. When the air length was 11cm, the membrane comprehensive performance was the best.


2013 ◽  
Vol 750-752 ◽  
pp. 1941-1944
Author(s):  
Jiao Jiao Dong ◽  
Yu Feng Zhang ◽  
Dong Qing Liu

In this article, a series of the PVDF/PPTA blend membranes with porous structure and excellent performance were successfully prepared by the phase transformation method. The effect of the mass ratio of W(PVDF)/W(PPTA) was systematically investigated.The morphology of the blend membranes were examined using scanning electron microscope (SEM). The permeation performance was characterized by measuring pure water flux. Meanwhile, the mechanical properties of membranes were researched. The experiment results confirmed that the blending ratio is a major factor to influence the structure and performance of PVDF/PPTA blend membrane. The blend membranes possess much better permeability than pure PVDF membrane and fairly good the mechanical properties especially for the membrane made by PVDF : PPTA=6 : 1.


2020 ◽  
Vol 21 (1) ◽  
pp. 30
Author(s):  
Dewi Mustika Rahim ◽  
Netti Herawati ◽  
Hasri Hasri

ABSTRAK Telah dilakukan penelitian tentang sintesis nanopartikel perak menggunakan bioreduktor ekstrak daun teh hijau (Camellia Sinensis) dengan iradiasi microwave. yang untuk mengetahui pengaruh waktu sintesis dan pengaruh pH stabilizer terhadap sintesis nanopartikel perak ekstrak daun teh hijau dengan iradiasi microwave serta karakterisasinya. Larutan AgNO3 3 mM direduksi menggunakan ekstrak daun teh hijau dan di iradiasi microwave pada variasi waktu sintesis 1-5 menit. Penentuan waktu sintesis optimal menggunakan spektrofotometer UV-Vis diukur setiap 1 menit. Nanopartikel dengan waktu sistesis 4 menit, pH stabilizer menggunakan asam sitrat dan NaOH dengan pH 6-9. Karakterisasi nanopartikel menggunakan instrumen SEM-EDS (Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy) dan PSA (Particle Size Analyzer). Hasil penelitian menunjukkan bahwa waktu sintesis optimal adalah 4 menit. Morfologi nanopatikel perak yang dikarakterisasi menggunakan SEM (Scanning Electron Microscopy) yang dihasilkan cenderung beragregasi. Adanya kecenderungan nanopartikel untuk beragregasi menyebabkan ukuran atau diameter nanopartikel tidak seragam. Ukuran dan distribusi ukuran nanopartikel perak dikarakterisasi menggunakan PSA(Particle Size Analyzer) dihasilkan pada pH 6 antara 31,01 – 402,44 nm dengan rata-rata ukuran sebesar 91 nm, pH 7 antara 35,03 – 740,899 nm dengan rata-rata ukuran sebesar 106,3 nm, pH 8 antara 39,58 – 193,48 nm dengan rata-rata ukuran 71,7, dan pH 9 antara 35,03 – 171,25 nm dengan rata-rata ukuran sebesar 64,4 nm. Disimpulkan bahwa hasil sintesis nanopartikel perak terkecil diperoleh pada pH 9 dan waktu sintesis 4 menit. Kata kunci: Ekstrak Daun Teh Hijau, Nanopartikel Perak, Iradiasi Microwave ABSTRACT Research has been carried out on the synthesis of silver nanoparticles using a bioreductor of green tea leaf extract (Camellia Sinensis) by irradiation microwave.This research aimed to determine the effect of synthesis time and pH stabilizer on the synthesis of silver nanoparticles of green tea leaf extract by microwave irradiation and it’s characterization. The 3 mM AgNO3 solution was reduced using green tea leaf extract and microwave irradiated in a variation of the synthesis time 1-5 minutes. The determining optimum of sythesis time was done by analysis of UV-Vis spectrum for every minutes. Nanoparticles with a synthesis time of 4 minutes, the stabilizer of silver nanoparticles used citric acid and NaOH with a pH of 6-9. Characterization of nanoparticles using SEM-EDS instrument (Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy) and PSA (Particle Size Analyzer). The results showed that the optimal synthesis time was 4 minutes. The morphology of silver nanopaticles characterized using SEM produced tends to aggregate. The tendency of nanoparticles to aggregate causes size or diameter of nanoparticles was random. The size and distribution of size silver nanoparticles characterized using PSA were produced at pH 6 between 31.01 - 402.44 nm with an average size of 91 nm, pH 7 between 35.03 - 740,899 nm with an average size amounting to 106.3 nm, pH 8 between 39.58 - 193.48 nm with an average size of 71.7, and pH 9 between 35.03 - 171.25 nm with an average size of 64.4 nm. It was concluded that the synthesis of the smallest silver nanoparticles was obtained at pH 9 and synthesis time of 4 minutes. Keywords: Green Tea Leaf Extract, Silver Nanoparticles, Microwave Irradiation


2014 ◽  
Vol 699 ◽  
pp. 305-310
Author(s):  
Asmadi Ali ◽  
Rosli Mohd Yunus ◽  
Mohamad Awang ◽  
Anwar Johari ◽  
Ramli Mat

Rheological factor such as shear rate during membrane fabrication process has an effect on properties, structures and performance of membranes. Flat sheet asymmetric PSf/CAP blend membranes were prepared using an automatic casting machine at different shear rates in the range of 42.0 to 201.0 s-1. Results showed that increasing the shear rate from 42.0 to105 s-1 has increased the molecular orientation and thickness which then reduces the water content, porosity and pure water flux of PSf/CAP blend membranes. However, further increasing the shear rate beyond 105 s-1has resulted in an increase in the water content of PSf/CAP blend membranes.


2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Bi Bi Zainab Mazhari ◽  
Dayanand Agsar

Extracellular gold nanoparticles synthesized by Streptomyces tuirus DBZ39 were explored for the detection of phenols in the effluent of fertilizer and distillery industries. An average size of 27–56 nm gold nanoparticles was produced and confirmed by UV-vis absorption spectrum, scanning electron microscopy, and energy dispersive X-ray analysis. In the present investigation visual detection of phenols in the effluent samples by gold nanoparticles is enhanced by sodium sulphate. The detection is achieved successfully within 2 min, with change in color of the effluent samples. Use of biologically originated gold nanoparticles along with salt for the detection of phenols from industrial effluents is a novel approach.


2012 ◽  
Vol 452-453 ◽  
pp. 278-281
Author(s):  
Yun Сhao Mu ◽  
Bao Yan Liang

Titanium carbonitride, V(C, N) has been prepared by combustion synthesis from V powders and a carbon-nitrogen precursor. The phase composition of the sample was investigated by X-ray diffraction. The scanning electron microscopy image indicates that the average size of the obtained V(C, N) grains was 1µm.


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