Effect of the structure of cellulose acetate membranes on their permeability, electrical conductivity and rejection

1990 ◽  
Vol 55 (12) ◽  
pp. 2933-2939 ◽  
Author(s):  
Hans-Hartmut Schwarz ◽  
Vlastimil Kůdela ◽  
Klaus Richau

Ultrafiltration cellulose acetate membrane can be transformed by annealing into reverse osmosis membranes (RO type). Annealing brings about changes in structural properties of the membranes, accompanied by changes in their permeability behaviour and electrical properties. Correlations between structure parameters and electrochemical properties are shown for the temperature range 20-90 °C. Relations have been derived which explain the role played by the dc electrical conductivity in the characterization of rejection ability of the membranes in the reverse osmosis, i.e. rRO = (1 + exp (A-B))-1, where exp A and exp B are statistically significant correlation functions of electrical conductivity and salt permeation, or of electrical conductivity and water flux through the membrane, respectively.

2012 ◽  
Author(s):  
Darunee Bhongsuwan ◽  
Tripob Bhogsuwan ◽  
Narumol Buangam ◽  
Waneerat Mangkalatas

Cellulose acetate (CA) membrane was produced from CA powder, formamid, and acetone. Annealing temperature of 80C and evaporation times of 30, 60, and 90 seconds were chosen in preparation of the CA membranes named R530, R560, and R590, respectively. The membranes were tested using a dead-end stirred cell for filtration of NaCl salt, iron, manganese, and arsenic in the laboratory-prepared water and groundwater. Results of the tests using a membrane R530 at 400 psi showed, that the rejection efficiencies for salt, iron, and manganese in laboratory-prepared water with 3000 ppm NaCl , 2.0 ppm Fe, and 2.0 ppm Mn were 87%, 99%, and 92%, respectively, with a permeate flux of 21 Lm-2hr-1. Tests for the groundwater containing 4815 ppm NaCl and 5.48 ppm Mn without acid treatment showed that membrane R530 gave the flux and rejection for salt and manganese at 24 Lm-2hr-1, 85% and 98%, and for iron and manganese at 21 Lm-2hr-1, 93% and 99%, respectively. In the filtration of arsenic, the prepared membrane had a As rejection of 68 - 70% at 300 and 400 psi when the feed was the laboratory prepared 1 ppm As+3 contaminated water but it was found to be more than 82 - 96% when the feed was a natural water. This is probably because the prepared membrane had a higher rejection efficiency for As+5 ions than As+3 ions. Ion selective capability of the CA membrane shows the potential to use the membrane in filtration of selective ions. Key words: Cellulose acetate membrane, reverse osmosis, nano-filtration, contaminated water, dead-end stirred cell


2017 ◽  
Vol 9 (2) ◽  
pp. 91-98
Author(s):  
Rina Apriani ◽  
Taufiqur Rohman ◽  
Kamilia Mustikasari

The research of synthesis and characterization of cellulose acetate membranes fromoil palm empty fruit bunches (OPEFB) had been done. The purpose of this research is tofind out the characteristics of the cellulose acetate membrane from cellulose acetate ofOPEFB. The cellulose acetate membrane was prepared using the cellulose acetate (CA)and chloroform as solvent in the ratio 1:6, and the variations of polietilena glycol (PEG) asadditives were 10%, 20%, and 30% w/w. Membrane characterization was done inpermeability (flux), permselektivitas (rejection), and membrane morphology. The test wasperformed on water, T-­70;; 1% w/v and T-­500;; 1% w/v dextran solution. The resultsshowed that cellulose acetate membrane had the best characteristic in the addition ofPEG/S 10% w/w. The permeability was 55.54 L/m2hour in water, 18.48 L/m2hour fordextran T-­70 and 5.14 L/m2hour for dextran T-­500. The perm selectivity was 67.24% fordextran T-­70 and 79.46% for dextran T-­500. The SEM (Scanning Electron Microscope)analysis on membrane pore showed that the distribution of pore sizes is fine.Keywords : membrane, cellulose acetate, oil palm empty fruit bunches


2018 ◽  
Vol 1 (1) ◽  
pp. 26-31 ◽  
Author(s):  
B Babu ◽  
K Mohanraj ◽  
S Chandrasekar ◽  
N Senthil Kumar ◽  
B Mohanbabu

CdHgTe thin films were grown onto glass substrate via the Chemical bath deposition technique. XRD results indicate that a CdHgTe formed with a cubic polycrystalline structure. The crystallinity of CdHgTe thin films is gradually deteriorate with increasing the gamma irradiation. EDS spectrums confirms the presence of Cd, Hg and Te elements. DC electrical conductivity results depicted the conductivity of CdHgTe increase with increasing a gamma ray dosage


2006 ◽  
Vol 111 ◽  
pp. 99-102 ◽  
Author(s):  
A.A. Ahmed ◽  
Faiz Mohammad

The films of polyaniline:polyethyleneterephthalate films were prepared by polymerizing aniline soaked in polyethyleneterephthalate films of different thicknesses. The films were characterized by FTIR as well as for their electrical properties. The electrical properties of the films were observed to be of good quality as almost all the films showed a great increase in their electrical conductivity from insulator to semiconductor region after doping with hydrochloric acid. All the films in their doped state follow the Arrhenius equation for the temperature dependence of electrical conductivity from 35 to 115oC. The thermooxidative stability was studied by thermogravimetry and differential thermal analysis. The stability in terms of dc electrical conductivity retention was also studied under ambient conditions by two slightly different techniques viz. isothermal and cyclic techniques. The dc electrical conductivity of the films was found to be stable below 90oC for all the films under ambient conditions.


1979 ◽  
Vol 24 (5) ◽  
pp. 1191-1203 ◽  
Author(s):  
Hiroshi Nomura ◽  
Manabu Senō ◽  
Hiroshi Takahashi ◽  
Takeo Yamabe

2021 ◽  
Vol 254 ◽  
pp. 117407
Author(s):  
Mónica A. Silva ◽  
Efres Belmonte-Reche ◽  
M.T. Pessoa de Amorim

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