Carbon nanotube enhanced membrane distillation for simultaneous generation of pure water and concentrating pharmaceutical waste

2012 ◽  
Vol 90 ◽  
pp. 239-245 ◽  
Author(s):  
Ken Gethard ◽  
Ornthida Sae-Khow ◽  
Somenath Mitra
Keyword(s):  
Carbon Nanotube ◽  
Pure Water ◽  
Membrane Distillation ◽  
Simultaneous Generation ◽  
Pharmaceutical Waste

scholarly journals Separation and Recycling of Concentrated Heavy Metal Wastewater by Tube Membrane Distillation Integrated with Crystallization

Membranes ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 19 ◽  
Author(s):  
Xiang-Yang Lou ◽  
Zheng Xu ◽  
An-Ping Bai ◽  
Montserrat Resina-Gallego ◽  
Zhong-Guang Ji
Keyword(s):  
Heavy Metal ◽  
Membrane Fouling ◽  
Pure Water ◽  
Sharp Decrease ◽  
Membrane Distillation ◽  
Water Yield ◽  
Mixed System ◽  
Mixed Solutions ◽  
Membrane Flux ◽  
Salt Crystals

Tube membrane distillation (MD) integrated with a crystallization method is used in this study for the concurrent productions of pure water and salt crystals from concentrated single and mixed system solutions. The effects of concentrated Zn2+ and Ni2+ on performance in terms of membrane flux, permeate conductivity, crystal recovery rates, and crystal grades are investigated. Preferred crystallization and co-crystallization determinations were performed for mixed solutions. The results revealed that membrane fluxes remained at 2.61 kg·m−2·h−1 and showed a sharp decline until the saturation increased to 1.38. Water yield conductivity was below 10 μs·cm−1. High concentrated zinc and nickel did not have a particular effect on the rejection of the membrane process. For the mixed solutions, membrane flux showed a sharp decrease due to the high saturation, while the conductivity of permeate remained below 10 μs·cm−1 during the whole process. Co-crystallization has been proven to be a better method due to the existence of the SO42− common-ion effect. Membrane fouling studies have suggested that the membrane has excellent resistance to fouling from highly concentrated solutions. The MD integrated with crystallization proves to be a promising technology for treating highly concentrated heavy metal solutions.

scholarly journals Fabrication and Performance Evaluation of Integrated Solar-Driven Membrane Distillation System with Serpentine-shape of Flat Plate Solar Collector for Seawater Desalination

2019 ◽  
Vol 23 (3) ◽  
Author(s):  
M. A. H. M. Hanoin ◽  
N. S. Mohammed ◽  
M. A. I. Z. Arris ◽  
A. I. A. Bakar ◽  
N. M. Mokhtar ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Flat Plate ◽  
Solar Collector ◽  
Pure Water ◽  
Feed Solution ◽  
Membrane Distillation ◽  
The Self ◽  
Permeate Flux ◽  
Salt Rejection ◽  
Flat Plate Solar Collector

Solar-powered membrane distillation (SPMD) system has gained its popularity in desalination application for past decade credit to the system efficiency in producing pure water and the utilization of renewable energy. However, most of the past SPMD works used commercial solar thermal collector (STC) as the thermal energy supply to the feed solution and the study only focused on the performance of the system in terms of flux and salt rejection. In this work, a self-made flat plate solar collector (FPSC) with the serpentine-shape pipe was designed and fabricated to study the effect of the STC towards the membrane performance. Before testing, a simulation work of the fluid flow inside the serpentine-shape pipe of the FPSC was analyzed using NX 10.0 computer-aided design simulation. After that, the efficiency of the self-made FPSC system was tested directly to sunlight in order to identify the maximum irradiance and the temperature of the feed solution. Due to the fluctuation of solar irradiance, the experimental setup of the SPMD system was tested using a solar simulator, and the performance was compared with the membrane distillation (MD) system without integration with FPSC system. Based on the simulation data, it can be concluded that the heat losses across the pipe are due to the slower fluid velocity and sudden pressure drop, which attributed to centripetal force and pressure differences. Meanwhile, the outdoor evaluation data showed that the temperatures of collector and water inside the feed tank could reach up to 84°C and 64°C, respectively when the maximum irradiance of 938 W/m2 was applied. For the performance evaluation between with and without the self-made FPSC system, it can be seen that only marginal difference can be observed for the permeate flux and salt rejection with an average difference of 6.06% and 1.29%, respectively.

scholarly journals Distillate Flux Enhancement of Direct Contact Membrane Distillation Modules with Inserting Cross-Diagonal Carbon-Fiber Spacers

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 973
Author(s):  
Chii-Dong Ho ◽  
Luke Chen ◽  
Jun-Wei Lim ◽  
Po-Hung Lin ◽  
Pin-Tsen Lu
Keyword(s):  
Carbon Fiber ◽  
Direct Contact ◽  
Pure Water ◽  
Water Productivity ◽  
Membrane Distillation ◽  
Design Parameters ◽  
Countercurrent Flow ◽  
Flux Enhancement ◽  
Direct Contact Membrane Distillation ◽  
Theoretical Predictions

A new design of direct-contact membrane distillation (DCMD) modules with cross-diagonal carbon-fiber spacers of various hydrodynamic angles in flow channels to promote turbulence intensity was proposed to enhance pure water productivity. Attempts to reduce the temperature polarization coefficient were achieved by inserting cross-diagonal carbon-fiber spacers in channels, which create wakes and eddies in both heat and mass transfer behaviors to enhance the permeate flux enhancement. A simplified equation was formulated to obtain the theoretical predictions of heat transfer coefficients in the current DCMD device. The permeate fluxes and temperature distributions of both hot and cold feed streams are represented graphically with the inlet volumetric flow rate and inlet temperature of the hot saline feed stream as parameters. The higher distillate flux of countercurrent-flow operations for saline water desalination was accomplished as compared to the concurrent-flow operations of various hydrodynamic angles. The results show that the agreement between the theoretical predictions and experimental results is reasonably good. The effects of countercurrent-flow operations and inserting carbon fiber spacers have confirmed technical feasibility and device performance enhancement of up to 45%. The influences of operating and design parameters on the pure water productivity with the expense of energy consumption are also discussed.

scholarly journals Single-Walled Carbon Nanotube (SWCNT) Loaded Porous Reticulated Vitreous Carbon (RVC) Electrodes Used in a Capacitive Deionization (CDI) Cell for Effective Desalination

Nanomaterials ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 527 ◽  
Author(s):  
Ali Aldalbahi ◽  
Mostafizur Rahaman ◽  
Mohammed Almoiqli ◽  
Abdelrazig Hamedelniel ◽  
Abdulaziz Alrehaili
Keyword(s):  
Carbon Nanotube ◽  
Pure Water ◽  
Water Desalination ◽  
Vitreous Carbon ◽  
Isotherm Models ◽  
Capacitive Deionization ◽  
Composite Electrodes ◽  
Reticulated Vitreous Carbon ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon

Acid-functionalized single-walled carbon nanotube (a-SWCNT)-coated reticulated vitreous carbon (RVC) composite electrodes have been prepared and the use of these electrodes in capacitive deionization (CDI) cells for water desalination has been the focus of this study. The performance of these electrodes was tested based on the applied voltage, flow rate, bias potential and a-SWCNT loadings, and then evaluated by electrosorption dynamics. The effect of the feed stream directly through the electrodes, between the electrodes, and the distance between the electrodes in the CDI system on the performance of the electrodes has been investigated. The interaction of ions with the electrodes was tested through Langmuir and Freundlich isotherm models. A new CDI cell was developed, which shows an increase of 23.96% in electrosorption capacity compared to the basic CDI cells. Moreover, a comparison of our results with the published results reveals that RVC/a-SWCNT electrodes produce 16 times more pure water compared to the ones produced using only CNT-based electrodes. Finally, it can be inferred that RVC/a-SWCNT composite electrodes in newly-developed CDI cells can be effectively used in desalination technology for water purification.

Enhanced durability and hydrophobicity of carbon nanotube bucky paper membranes in membrane distillation

2011 ◽  
Vol 376 (1-2) ◽  
pp. 241-246 ◽  
Author(s):  
Ludovic Dumée ◽  
Vincent Germain ◽  
Kallista Sears ◽  
Jürg Schütz ◽  
Niall Finn ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Membrane Distillation ◽  
Bucky Paper

scholarly journals Kapok Fibre as Membrane Distillation for Humic Acid Wastewater Treatment

2019 ◽  
Vol 8 (11) ◽  
pp. 786-789
Keyword(s):  
Wastewater Treatment ◽  
Humic Acid ◽  
Physical Properties ◽  
Pure Water ◽  
Membrane Distillation ◽  
Absorption Test ◽  
Permeate Flux ◽  
Hydrophobic Properties ◽  
Thermal Desalination ◽  
Feed Temperature

Membrane distillation (MD) is a process of combining membrane with thermal desalination where it operates at two different temperatures which are hot and cold. A vapour pressure resulted between the temperature differences of two sides of the membrane is called permeate flux. In this study, kapok fibre, which provides hydrophobic properties, has been chosen as an alternative solution for synthetic membrane in the MD process. Therefore, the primary purpose of this research is to investigate the effect of feed temperature ranging from 40 to 70℃ towards the separation of pure water from humic acid (HA) wastewater. An experimental investigation for the performance of vacuum membrane distillation (VMD) system was performed to treat the HA wastewater to produce pure water. The experimental set up of VMD was set with kapok fibre acting as a barrier that separates the collected pure water from HA wastewater, which is conducted for four hours. Based on this study, the increase in the amount of calculated permeate flux correlates to the increase of feed temperature. The calculated permeate flux is 0.237 kgh-1m -2 at the temperature of 40℃. The amount of calculated flux increases steadily to 0.4 and 0.6 kgh-1m -2 respectively for every 10℃ increments. Furthermore, the physical properties of kapok fibre were analysed by using a scanning electron microscope (SEM). Surface morphology of the kapok fibre at the condition of before and after the MD process were studied without subjecting any chemical treatment on it. Accordingly, the physical properties of the kapok fibre were seen different after the MD process conducted. Additionally, the hydrophobic properties of the kapok fibre were evaluated by using an absorption test. The absorption test was conducted at varies temperature, which results in the highest percentage of absorptivity 4.823 % at 60℃. The hydrophobic kapok fibre has shown excellent properties that can be applied in the MD process and utilised in wastewater treatment.

scholarly journals Modification of porous polyetherimide hollow fiber membrane by dip-coating of Zonyl® BA for membrane distillation of dyeing wastewater

2021 ◽  
Author(s):  
S. A. Mousavi ◽  
Z. Arab Aboosadi ◽  
A. Mansourizadeh ◽  
B. Honarvar
Keyword(s):  
Pore Size ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Membrane Surface ◽  
Pure Water ◽  
Dip Coating ◽  
Membrane Distillation ◽  
Permeate Flux ◽  
Fiber Membrane ◽  
Air Gap Membrane Distillation

Abstract Wetting and fouling have significantly affected the application of membrane distillation (MD). In this work, a dip-coating method was used for improving surface hydrophobicity of the polyetherimide (PEI) hollow fiber membrane. An air gap membrane distillation (AGMD) process was applied for treatment of the methylene blue (MB) solution. The porous PEI membrane was fabricated by a dry-wet spinning process and the hydrophobic 2-(Perfluoroalkyl) ethanol (Zonyl® BA) was used as the coating material. From FESEM, the modified PEI-Zonyl membrane showed an open structure with large finger-like cavities. The modified membrane displayed a narrow pore size distribution with mean pore size of 0.028 μm. The outer surface contact angle of the PEI-Zonly membrane increased from 81.3° to 100.4° due to the formation of an ultra-thin coated layer. The pure water flux of the PEI-Zonyl membrane was slightly reduced compared to the pristine PEI membrane. The permeate flux of 6.5 kg/m2 h and MB rejection of 98% was found for the PEI-Zonyl membrane during 76 h of the AGMD operation. Adsorption of MB on the membrane surface was confirmed based on the Langmuir isotherm evaluation, AFM and FESM analysis. The modified PEI-Zonyl membrane can be a favorable alternative for AGMD of dyeing wastewaters.

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