scholarly journals Membran nonofiltrasi untuk penghilangan ion valensi tinggi dan senyawa organik dari sumber air salinitas tinggi

2018 ◽  
Vol 5 (3) ◽  
pp. 478 ◽  
Author(s):  
Iman Ciptaraharja ◽  
Veronica S. Praptowidodo

Utilization of nanofiltration membrane for high valence ion and organic compound removing from high salinized water source.The influence of solvent selection to membrane morphology for cellulose acetate nanofiltration membrane preparation in mass transfer of a multistage reverse osmosis process is studied. Membrane is prepared via precipitation immersion technique. The polymer used in this study is cellulose acetate (CA) with a concentration of 25 %-w. The feed concentration of univalent ion solution (NaCl) is varied between 2000-16.000 mg/L. The operating pressure is adjusted such that the operating pressure is three times of the osmotic pressure of NaCl solution. The concentration of bivalent ion (CaCl2), trivalent ion (FeCl3), and organic substance (glucose) are 200 mg/L, 50 mg/L, and 100 mg/L, respectively. The morphology of the membrane is characterized using Scanning Electron Microscopy (SEM). Membrane CA-01 (CA/DMF/Water) is a nanofiltration membrane with a thinner active layer and a more porous support layer than membrane CA-02 (CA/Aceton/Watter) which is categorized as a reverse osmosis membrane. A reduced feed concentration (at a fixed operating pressure) gives an elevated flux however the rejection is decreased. Meanwhile, an elevated operating pressure (at a fixed feed concentration) gives an elevated flux and rejection. Membrane CA-01 has met the requirement as a nanofiltration membrane since it gives 66 % rejection for NaCl at 20 Bar. At the same operating pressure, membrane CA-01 gives rejection for CaCl2, FeCl3, and glucose of 80.45%, 82.14%, and 83.42%, respectively.Keywords: Cellulose Acetate, Membrane, Multistage, Nanotiltration, Reverse Osmosis, Saline WaterAbstrakPenelitian ini dilakukan untuk mempelajari pengaruh jenis pelarut dalam pembuatan membran nanofiltrasi dari polimer selulosa asetat terhadap struktur morfologi membran dalam peristiwa perpindahan massa pada proses pemisalan osmosis balik multitahap. Teknik pembuatan membran yang digunakan adalah presipitasi imersi. Polimer membran yang digunakan adalah seulosa asetat (CA) pada konsentrasi 25 %-berat. Umpan yang digunakan adalah larutan ion valensi satu (NaCl) dengan variasi konsentrasi antara 2000 hingga 16.000 mg/L. Tekanan operasi diatur sedemikian rupa sehingga nilai rekanan operasi adalah sekitar tiga kali tekanan osmotik larutan NaCl. Percobaan juga dilakukan untuk umpan larutan ion valensi dua (CaCl2), ion valensi tiga (FeCl3), dan senyawa organik (glukosa) dengan konsentrasi, berturut-turut, adalah 200 mg/L, 50 mg/L,  dan 100 mg/L. Struktur morfologi membran diuji menggunakan metoda Scanning Electron Microscopy (SEM). Membran CA-01 (CA/DMF/Air) merupakan membran nanofiltrasi dengan lapisan aktif yang lebih tipis dan ukuran pori lapisan penyangga yang lebih besar daripada membran CA-02 (CA/Aseton/Air), yang termasuk ke dalam membran osmosis balik. Penurunan konsentrasi umpan pada tekanan operasi yang tetap memberikan nilai fluks yang meningkat, namun memberikan nilai rejeksi yang menurun. Sementara itu, peningkatan tekanan operasi pada konsentrasi umpan yang tetap akan memberikan nilai fluks dan rejeksi yang meningkat. Membran CA-01 telah memenuhi persyaratan sebagai membran nanofiltrasi dengan rejeksi NaCl mencapai 66 % pada tekanan 20 Bar. Pada tekanan yang sama membran CA-01 memberikan nilai rejeksi untuk CaCl2, FeCl3, dan glukosa berturut-turut sebesar 80,45%, 82,14%, dan 83,42 %.Kata Kunci: Air Salinitas Tinggi, Membran, Multitahap, Nanofiltrasi, Osmosis Balik, Selulosa Asetat.

Author(s):  
M. Yamada ◽  
K. Ueda ◽  
K. Kuboki ◽  
H. Matsushima ◽  
S. Joens

Use of variable Pressure SEMs is spreading among electron microscopists The variable Pressure SEM does not necessarily require specimen Preparation such as fixation, dehydration, coating, etc which have been required for conventional scanning electron microscopy. The variable Pressure SEM allows operating Pressure of 1˜270 Pa in specimen chamber It does not allow microscopy of water-containing specimens under a saturated vapor Pressure of water. Therefore, it may cause shrink or deformation of water-containing soft specimens such as plant cells due to evaporation of water. A solution to this Problem is to lower the specimen temperature and maintain saturated vapor Pressures of water at low as shown in Fig. 1 On this technique, there is a Published report of experiment to have sufficient signal to noise ratio for scondary electron imaging at a relatively long working distance using an environmental SEM. We report here a new low temperature microscopy of soft Plant cells using a variable Pressure SEM (Hitachi S-225ON).


Author(s):  
Mohd. Ghazali Mohd. Nawawi ◽  
Le T. Ngoc Tram

Kajian pervaporasi (PV) penyahidratan isopropanol (IPA) menggunakan membran kitosan terubahsuai telah dijalankan. Membran disediakan daripada kitosan dan diubahsuai menggunakan zeolite–A. Zeolit–A yang diketahui beratnya ditambahkan ke dalam pelarut berasid dan diaduk untuk menghasilkan larutan homogen. Kepingan kitosan kemudian ditambahkan ke dalam larutan tersebut dan diaduk semalaman. Pelbagai nisbah zeolit–A dan kitosan daripada 1:20 hingga 1:2 digunakan untuk menghasilkan membran kitosan terubahsuai. Larutan kitosan–zeolit–A dituangkan ke atas plat kaca dan dikeringkan pada suhu bilik. Membran yang dikeringkan kemudian dirawat dengan larutan alkali dan dibasuh di dalam air ternyahion. Sifat hidrofilik membran dikaji melalui ujian pengembungan. Ujian dijalankan dalam campuran 90 wt.% IPA–air. Keputusan menunjukkan bahawa darjah pengembungan berkurangan dengan penambahan zeolit–A. Sifat mekanikal membran dikaji untuk kekuatan tegangan dan pemanjangan pada takat putus. Kemudian, membran tersebut dikaji untuk pemisahan campuran IPA–air pada tekanan 720 mmHg di bawah vakum. Kepekatan suapan diubah daripada 0 hinga 95 wt.% IPA dan suhu suapan diubah daripada 30 hingga 70°C. Keputusan menunjukkan bahawa nisbah 1:8 antara zeolit dan kitosan menghasilkan kombinasi terbaik untuk mengubahsuai membran bagi pemisahan campuran IPA–air. Struktur morfologi membran kitosan–zeolit–A dengan nisbah 1:8 dan 1:2 berat zeolit–A/berat kiotsan dikaji menggunakan Scanning Electron Microscopy (SEM). Keputusan menunjukkan bahawa membran yang dihasilkan adalah padat dan tiada liang dapat diperhatikan. Penambahan zeolit tidak mengubah struktur membran. Kata kunci: Pervaporasi, penyahidratan, membrane, kitosan, zeolite-A, isopropanol Pervaporation (PV) dehydration of isopropanol (IPA) using modified chitosan membranes was studied. The membranes were prepared from chitosan and modified by using zeolite–A. Pre–weighed amount of zeolite–A was added into acidic solvent and stirred to produce homogeneous solution. Chitosan flakes were then added into the solution and stirred overnight. Various ratios of zeolite–A and chitosan from 1:20 to 1:2 were used to produce the modified chitosan membranes. The chitosan–zeolite A solution was casted on a glass plate and dried at room temperature. The dried membranes were treated with alkaline solution and thoroughly washed in deionized water. The hydrophilicity of the membranes was studied through the swelling test. The test was carried out in a 90 wt% IPA–water mixture. The result showed that the degree of swelling decreased with the increase of the amount of zeolite–A. The mechanical properties of membranes were also tested for the tensile strength and elongation at break. Then, the membranes were investigated for the PV separation of IPA–water mixtures at the permeate pressure of 720 mmHg under vacuum. The feed concentration was varied from 0 to 95 wt% IPA, and the feed temperature was varied from 30 to 70°C. The results showed that the ratio 1:8 of zeolite–A and chitosan produced the best combination to modify the membrane for the separation of water–IPA mixtures. The structural morphologies of the chitosan filled zeolite–A membranes with ratio 1:8 and 1:2 wt zeolite–A/wt chitosan was studied under Scanning Electron Microscopy (SEM). The results showed that the membranes were dense, and no pores were visible. The addition of the zeolite did not alter the structure of the membranes. Key words: Pervaporation, dehydration, membrane, chitosan, zeolite-A, isopropanol


2019 ◽  
Vol 815 ◽  
pp. 139-144
Author(s):  
Tao Mu

In this paper, acrylic acid was grafted to chitosan in order to change the structure; polymer was obtained from modified chitosan. A series of novel toughened composite NF memebranes were prepared by over-coating the polysulfone ultrafiltration membrane with the polymer of modified chitosan. The chitosan derivatives and the polymer were characterised by infrared spectrophotometer (IR); the structure of the membrane was characrerised by scanning electron microscopy (SEM) and atomic force microscope (AFM). The composite NF membrane’s performances were strictly related to the structure of polymer. The rejection of the membrane was 96.3% with flux as high as 386.46 L m-2 h-1 with the 1000 mg/L of NaCl. Tensile strength of membrane increased 46%. The HCl (5%) resistance increased from 20.3 to 36.8h. The NaOH (5%) resistance increased from 18.3 to 31.6h. These results indicated the prepared toughened composite NF memebrane was excellent NF membrane, which had a wide application prospect.


2019 ◽  
Vol 5 (2) ◽  
pp. 129
Author(s):  
Rosmanisah Mohamat

In this work, graphene oxide (GO) and titanium dioxide (TiO2) were used as an additive to fabricate the nanofiltration (NF) membrane. GO was synthesised via electrochemical exfoliation method utilising sodium bis(3,5,5-trimethyl-1-hexyl) sulphosuccinate (AOT4) surfactant. The synthesised GO was then used to fabricate PVDF-based NF membrane namely PVDF/GO_TiO2 via non-solvent induced phase separation (NIPS) method. The effects of embedded GO and TiO2 on the morphology and structural properties of PVDF/GO_TiO2 were investigated by using field emission scanning electron microscopy (FESEM) and micro-Raman spectroscopy. The finding shows that PVDF/GO_TiO2 present thin and dense top layer supported by macro-voids sub-layer with sponge-like layer at the bottom. Based on its morphology, the fabricated PVDF/GO_TiO2 membrane is potential to be applied as membrane filtration for water treatment application.


2015 ◽  
Vol 752-753 ◽  
pp. 142-147
Author(s):  
Sharifah Abdullah ◽  
Nor Munirah Abdullah ◽  
Ramlah Mohd Tajuddin

This study was conducted in order to determine the suitable formula in developing a nanofiltration membrane using additive from kenaf core. Kenaf core was processed and analyse the suitable component to be used as the additive in formulation the nanofiltration membrane. Kenaf taken from National Kenaf and Tobacco Board (NKTB) Malaysia with code reference of V36 was used in this study. Cellulose of Kenaf core was extracted using Microcrystalline Cellulose (MCC) process at the Forestry Research Institute of Malaysia (FRIM). From few percentage of Kenaf cellulose with analyses using Flux Purewater Test, NaCl Test (Rejection Test), Molecular Weight Cut Off (MWCO) Test, Scanning Electron Microscopy (SEM) and Fourier Transform Infra Red (FTIR), the suitable percentage of Kenaf cellulose for nanofiltration flat sheet membrane was obtained.


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