Recovery of Valuable Solutes from Organic Solvent/Water Mixtures via Direct Contact Membrane Distillation (DCMD) as a Non-Heated Process

Recently, the demand for the recovery of valuable solutes from organic solvents/water mixtures has increased in various fields. Furthermore, due to the abundance of heat-sensitive valuable solutes, the demand for non-heated concentration technologies has increased. In this study, the direct contact membrane distillation (DCMD) using hydrophobic polyvinylidene difluoride (PVDF) hollow fiber membranes was investigated to confirm the possibility of recovering valuable solutes from organic solvents/water mixtures as a non-heated process. The DCMD with 1000 ppm NaCl aqueous solution achieved 0.8 kg/m2·h of vapor flux and >99.9% of NaCl retention, even at feed and coolant temperatures of 25 and 10 °C, respectively. Furthermore, when DCMD was conducted under various conditions, including feed temperatures of 25, 35 and 45 °C, and organic solvent concentration of 15, 30 and 50 wt%, using ethanol/water and acetonitrile/water mixtures containing 1000 ppm NaCl. A surfactant was also used as a valuable solute, in addition to NaCl. As a result, it was found that the total vapor flux increased with increasing temperature and concentration of organic solvents, as the partial vapor pressure of the organic solvents increased. Additionally, no solute leaked under any condition, even when the surfactant was used as a valuable solute.

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Comparison of Sweeping Gas and Direct Contact Membrane Distillation: Module Length Effect

ASME 2020 Heat Transfer Summer Conference ◽

10.1115/ht2020-8962 ◽

2020 ◽

Author(s):

Umar F. Alqsair ◽

Ahmed M. Alshwairekh ◽

Anas M. Alwatban ◽

Robert Krysko ◽

Alparslan Oztekin

Keyword(s):

Direct Contact ◽

Three Dimensional ◽

Concentration Field ◽

Local Variation ◽

Membrane Distillation ◽

Membrane Properties ◽

Effect Of Temperature ◽

Vapor Flux ◽

Direct Contact Membrane Distillation ◽

Sweeping Gas

Abstract Computational fluid dynamics simulations are conducted to compare the effect of module length in sweeping gas and direct contact membrane distillation systems for seawater desalination processes. In this work, the effect of temperature and concentration on the flux performance and temperature and concentration polarization characteristics are studied. CFD simulations are conducted in a three-dimensional module to characterize the steady-state velocity, temperature, and concentration field in the feed and permeate channel. The Reynolds number for the feed and the permeate stream is set to 500 and 1500, and thus the laminar flow model is adapted for each channel. The membrane properties are fixed in all cases considered. It is revealed that the local variation of the vapor flux, TPC, and CPC varies with module length in SGMD systems. However, the average values along the membrane in both module lengths do not vary much. Remedies for mitigating temperature polarization should be considered for future studies.

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Porous Hydrophobic–Hydrophilic Composite Hollow Fiber and Flat Membranes Prepared by Plasma Polymerization for Direct Contact Membrane Distillation

Membranes ◽

10.3390/membranes11020120 ◽

2021 ◽

Vol 11 (2) ◽

pp. 120 ◽

Cited By ~ 1

Author(s):

Ashok K. Sharma ◽

Adam Juelfs ◽

Connor Colling ◽

Saket Sharma ◽

Stephen P. Conover ◽

...

Keyword(s):

Hollow Fiber ◽

Direct Contact ◽

Plasma Polymerization ◽

Polyvinylidene Fluoride ◽

Hydrophobic Surface ◽

Diffusion Path ◽

High Water ◽

Membrane Distillation ◽

Vapor Flux ◽

Direct Contact Membrane Distillation

High water vapor flux at low brine temperatures without surface fouling is needed in membrane distillation-based desalination. Brine crossflow over surface-modified hydrophobic hollow fiber membranes (HFMs) yielded fouling-free operation with supersaturated solutions of scaling salts and their precipitates. Surface modification involved an ultrathin porous polyfluorosiloxane or polysiloxane coating deposited on the outside of porous polypropylene (PP) HFMs by plasma polymerization. The outside of hydrophilic MicroPES HFMs of polyethersulfone was also coated by an ultrathin coating of porous plasma-polymerized polyfluorosiloxane or polysiloxane rendering the surface hydrophobic. Direct contact membrane distillation-based desalination performances of these HFMs were determined and compared with porous PP-based HFMs. Salt concentrations of 1, 10, and 20 wt% were used. Leak rates were determined at low pressures. Surface and cross-sections of two kinds of coated HFMs were investigated by scanning electron microscopy. The HFMs based on water-wetted MicroPES substrate offered a very thin gas gap in the hydrophobic surface coating yielding a high flux of 26.4–27.6 kg/m2-h with 1 wt% feed brine at 70 °C. The fluxes of HFMs on porous PP substrates having a long vapor diffusion path were significantly lower. Coated HFM performances have been compared with flat hydrophilic membranes of polyvinylidene fluoride having a similar plasma-polymerized hydrophobic polyfluorosiloxane coating.

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The Effect of the Embedded Spacers on the Performance of Direct Contact Membrane Distillation System Operating With Different Inlet Feed Temperature

Volume 7: Fluids Engineering ◽

10.1115/imece2019-10723 ◽

2019 ◽

Author(s):

Anas M. Alwatban ◽

Ahmed M. Alshwairekh ◽

Umar F. Alqsair ◽

Robert Krysko ◽

Abdullah A. Alghafis ◽

...

Keyword(s):

Direct Contact ◽

Membrane Distillation ◽

Membrane Properties ◽

Functional Surface ◽

Feed Concentration ◽

Turbulent Structures ◽

Vapor Flux ◽

Direct Contact Membrane Distillation ◽

Dynamics Simulations ◽

Feed Temperature

Abstract Computational fluid dynamics simulations are used to model the effect of the inlet feed temperature in direct contact membrane distillation modules. Embedded spacers are used as a local mixing promoter tool. Net-type spacers of angle 45° are used as spacers. The presence of the spacers will mitigate the temperature and concentration polarization effects. The calculation of the vapor flux through the membrane is based on the Dusty-Gas model. The membrane is considered as a functional surface, and the embedded spacers are treated as impermeable surfaces. The vapor flux equation couples the variation of the vapor flux in the feed and the permeate channel with the variation of the feed concentration along the membrane. The flow is considered turbulent in channels containing embedded spacers. The k–ω SST turbulent model is used to characterize the steady-state turbulent structures inside the flow channels. The flow rate in the feed and the permeate channels is fixed. The membrane properties are also fixed. The inlet feed temperature is varying while fixing the inlet permeate temperature. The results indicate that the embedded spacers increase the vapor flux permeation while the temperature and concentration polarizations are mitigated. As the inlet feed temperature is increased, the effect of the embedded spacers becomes more significant.

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Enhanced Performance of Carbon Nanotube Immobilized Membrane for the Treatment of High Salinity Produced Water via Direct Contact Membrane Distillation

Membranes ◽

10.3390/membranes10110325 ◽

2020 ◽

Vol 10 (11) ◽

pp. 325 ◽

Cited By ~ 1

Author(s):

Madihah Saud Humoud ◽

Sagar Roy ◽

Somenath Mitra

Keyword(s):

Carbon Nanotube ◽

Membrane Fouling ◽

Direct Contact ◽

Produced Water ◽

High Salinity ◽

Membrane Surface ◽

Membrane Distillation ◽

Vapor Flux ◽

Ptfe Membrane ◽

Direct Contact Membrane Distillation

Membrane distillation (MD) is a promising desalination technology for the treatment of high salinity water. Here, we investigated the fouling characteristics of produced water obtained from hydraulic fracturing by implementing a carbon nanotube immobilized membrane (CNIM) via direct contact membrane distillation. The CNIM exhibited enhanced water vapor flux and antifouling characteristics compared to the pristine membrane. The normalized flux decline with the polytetrafluoroethylene (PTFE) membrane after 7 h of operation was found to be 18.2% more than the CNIM. The addition of 1-Hydroxy Ethylidene-1, 1-Diphosphonic acid (HEDP) antiscalant was found to be effective in reducing the membrane fouling. The salt deposition on the membrane surface was 77% less in the CNIM, which was further reduced with the addition of HEDP in the feed by up to 135.4% in comparison with the PTFE membrane. The presence of carbon nanotubes (CNTs) on the membrane surface also facilitated the regenerability of the membrane. The results indicated that the CNIM regained 90.9% of its initial water flux after washing, whereas the unmodified PTFE only regained 81.1% of its initial flux after five days of operation.

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Immobilization of Graphene Oxide on the Permeate Side of a Membrane Distillation Membrane to Enhance Flux

Membranes ◽

10.3390/membranes8030063 ◽

2018 ◽

Vol 8 (3) ◽

pp. 63 ◽

Cited By ~ 11

Author(s):

Worawit Intrchom ◽

Sagar Roy ◽

Madihah Humoud ◽

Somenath Mitra

Keyword(s):

Mass Transfer ◽

Graphene Oxide ◽

Direct Contact ◽

Membrane Distillation ◽

Water Vapor Flux ◽

Vapor Flux ◽

Ptfe Membrane ◽

Direct Contact Membrane Distillation ◽

Water Vapors ◽

Facile Fabrication

In this paper, a facile fabrication of enhanced direct contact membrane distillation membrane via immobilization of the hydrophilic graphene oxide (GO) on the permeate side (GOIM-P) of a commercial polypropylene supported polytetrafluoroethylene (PTFE) membrane is presented. The permeate side hydrophilicity of the membrane was modified by immobilizing the GO to facilitate fast condensation and the withdrawal of the permeate water vapors. The water vapor flux was found to be as high as 64.5 kg/m2·h at 80 °C, which is 15% higher than the unmodified membrane at a feed salt concentration of 10,000 ppm. The mass transfer coefficient was observed 6.2 × 10−7 kg/m2·s·Pa at 60 °C and 200 mL/min flow rate in the GOIM-P.

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Omniphobic palygorskite coated Janus membrane with enhanced fouling and wetting resistance for direct contact membrane distillation

Desalination ◽

10.1016/j.desal.2021.114986 ◽

2021 ◽

Vol 505 ◽

pp. 114986

Author(s):

Jiahui Zhang ◽

Nan Li ◽

Dong Wang ◽

Jinmei Li ◽

Yue Chen ◽

...

Keyword(s):

Direct Contact ◽

Membrane Distillation ◽

Direct Contact Membrane Distillation

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Corrigendum to “Preparation and characterization of PVDF flat-sheet membranes for direct contact membrane distillation” [Sep. Purif. Technol. 135 (2014) 211–222]

Separation and Purification Technology ◽

10.1016/j.seppur.2021.119197 ◽

2021 ◽

pp. 119197

Author(s):

Deyin Hou ◽

Hua Fan ◽

Qinliang Jiang ◽

Jun Wang ◽

Xiaohui Zhang

Keyword(s):

Direct Contact ◽

Membrane Distillation ◽

Direct Contact Membrane Distillation ◽

Flat Sheet

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Concentration of Bioactive Phenolic Compounds in Olive Mill Wastewater by Direct Contact Membrane Distillation

Molecules ◽

10.3390/molecules26061808 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1808

Author(s):

Rosa Tundis ◽

Carmela Conidi ◽

Monica R. Loizzo ◽

Vincenzo Sicari ◽

Rosa Romeo ◽

...

Keyword(s):

Direct Contact ◽

High Performance ◽

Biological Properties ◽

Membrane Distillation ◽

Olive Mill Wastewater ◽

High Concentration ◽

Direct Contact Membrane Distillation ◽

Reducing Activity ◽

Β Carotene ◽

Olive Mill

Olive mill wastewater (OMW), generated as a by-product of olive oil production, is considered one of the most polluting effluents produced by the agro-food industry, due to its high concentration of organic matter and nutrients. However, OMW is rich in several polyphenols, representing compounds with remarkable biological properties. This study aimed to analyze the chemical profile as well as the antioxidant and anti-obesity properties of concentrated fractions obtained from microfiltered OMW treated by direct contact membrane distillation (DCMD). Ultra-high performance liquid chromatography (UHPLC) analyses were applied to quantify some phenols selected as phytochemical markers. Moreover, α-Amylase, α-glucosidase, and lipase inhibitory activity were investigated together with the antioxidant activity by means of assays, namely β-carotene bleaching, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic) acid (ABTS) diammonium salts, 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and Ferric Reducing Activity Power (FRAP) tests. MD retentate—which has content of about five times greater of hydroxytyrosol and verbascoside and about 7 times greater of oleuropein than the feed—was more active as an antioxidant in all applied assays. Of interest is the result obtained in the DPPH test (an inhibitory concentration 50% (IC50) of 9.8 μg/mL in comparison to the feed (IC50 of 97.2 μg/mL)) and in the ABTS assay (an IC50 of 0.4 μg/mL in comparison to the feed (IC50 of 1.2 μg/mL)).

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