Sedigheh Daroumi; Mohammad Ali Aroon; Ramin Yavari; taher yousefi; Hossein Ghasemi mobtaker
Abstract
In this study, the flat sheet membranes including the neat polyethersulfone (PES) and the mixed matrix membranes (MMMs) containing 20 wt. % polyethersulfone (PES) and various amounts of Fe3O4 nanoparticles were prepared using wet phase inversion and conventional casting methods. Manganese ion rejection ...
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In this study, the flat sheet membranes including the neat polyethersulfone (PES) and the mixed matrix membranes (MMMs) containing 20 wt. % polyethersulfone (PES) and various amounts of Fe3O4 nanoparticles were prepared using wet phase inversion and conventional casting methods. Manganese ion rejection and permeate flux as a performance evaluation of the prepared membranes was studied and compared. The characteristics of the fabricated membranes and the synthesized nanoparticles were fulfilled by transmission electron microscopy, field emission scanning electron microscopy and contact angle measurement. The operational parameters such as polymer concentration, pressure, pH, manganese ion concentration and time for manganese ion rejection and permeability were firstly optimized on the neat PES membrane. In the next steps, the performance of the fabricated MMMs containing various amount of Fe3O4 nanoparticles and PES (20%wt.) was evaluated and compared under these optimized conditions. Under the optimal conditions obtained for the rejection of manganese ions by neat PES, the fabricated MMMs had better performance than the neat PES membrane. Also, the results showed that the best performance of the prepared MMMs with the manganese rejection percentage of 89.3% and permeate flux of 28.7 L.m-2.h was found to belong to the PES membranes containing 0.1 wt.% of Fe3O4.
Mourad Berrabah; Khadidja Benyahia; Ahlem Zerfa; Hassiba Bouabdesselam
Abstract
The Beni Saf Water Company (BWC) desalination plant in Ain Témouchent (Algeria) uses reverse osmosis technique. This process, which is based on dense membranes operating at high pressure, produces a permeate with characteristics that exceeds the necessary requirements. However, the Reverse Osmosis ...
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The Beni Saf Water Company (BWC) desalination plant in Ain Témouchent (Algeria) uses reverse osmosis technique. This process, which is based on dense membranes operating at high pressure, produces a permeate with characteristics that exceeds the necessary requirements. However, the Reverse Osmosis (RO) technique suffers from the following limitations: high energy consumption, low water recovery and excessive fouling of membranes. We conducted this work to contribute to the study of seawater desalination by introducing another system such as Nanofiltration (NF) to reduce energy consumption and retard the fouling of RO membranes. This research study is focused on the installation of Nanofiltration membranes to desalinate seawater with a salinity of about 35mg/L, in order to protect RO membranes and reduce their fouling. NF was found to be effective for partial and selective desalination of the studied seawater in single or two stages, with lower energy consumption than RO. The ESNA1-LF-LD Nanofiltration membrane is more suitable and competitive compared to SWC4-LD for seawater desalination with a 99% removal rate of multivalent ions. It allows for partial desalination and also allows for the preparation of water for industrial use (cooling....) at twice the pressure and at higher conversion rates (90%). These characteristics provide system designers with new options to reduce the capital cost of the system as well as the operating costs.
Alireza Nouri; Ramin Yavari; Mohammad Ali Aroon; Taher Yousefi
Abstract
In the present research work, the mixed matrix membranes (MMMs) containing various amount of polyethersulfone (PES) and functionalized multi-walled carbon nanotubes (fMWCNTs) were fabricated and used to investigate the removal of cobalt ions from wastewater by nanofiltration process. Pristine MWCNTs ...
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In the present research work, the mixed matrix membranes (MMMs) containing various amount of polyethersulfone (PES) and functionalized multi-walled carbon nanotubes (fMWCNTs) were fabricated and used to investigate the removal of cobalt ions from wastewater by nanofiltration process. Pristine MWCNTs and fMWCNTs were characterized by Fourier transformed infrared spectroscopy and thermogravimetric analysis. FESEM analysis revealed that the mixed matrix membranes have less surface defects and better membrane performance compared with neat polymeric in the removal of cobalt ions. Permeation test results showed that the MMM containing 22 wt. % PES and 0.6 wt. % fMWCNTs (with outer diameter of 10-20 nm) has the optimum performance from the permeability and cobalt removal point of view. In continuation, the effect of pressure, feed flow rate, cobalt concentration, permeation test time and feed solution pH on the removal of cobalt by selected the MMM was investigated. The obtained results indicated that only pressure has considerable effect on permeation flux. However, all parameters showed different influence on rejection percent of cobalt ions.
Mohammad Hadi Yousefi; Mohamad Mehdi Zerafat; Majid Shokri Doodeji; Samad Sabbaghi
Abstract
The objective of this work is to investigate the effect of dip-coating parameters on the performance of Alumina-PDMS hybrid nanofiltration membranes for water desalination. Ceramic supports used in this work were prepared with a 340 nm average pore size and 34% total porosity. The aim is to determine ...
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The objective of this work is to investigate the effect of dip-coating parameters on the performance of Alumina-PDMS hybrid nanofiltration membranes for water desalination. Ceramic supports used in this work were prepared with a 340 nm average pore size and 34% total porosity. The aim is to determine optimum conditions of dipping time, PDMS concentration, and withdrawal speed in order to achieve high rejection and flux values. Dip-coating parameters were considered as dipping time (60 - 120 s), withdrawal speed (5 - 15 mm/s) and PDMS concentration (10 - 20 wt. %). Hybrid membranes were characterized using FE-SEM and FTIR analysis techniques. Pure water flux and salt rejection were also measured to evaluate the rejection performance. Alumina-PDMS hybrid nanofiltration membranes fabricated with dipping time = 120 s, withdrawal speed = 15 mm/s and 10 wt. % PDMS exhibited the best performance giving 30.5% rejection for NaCl and 53.8% for Na2SO4.