A stepwise model of direct contact membrane distillation for application to large-scale systems: Experimental results and model predictions

Abstract HFP-co-PVDF/N6 hydrophobic/hydrophilic dual-layer membrane was used to study desalination with direct contact membrane distillation (DCMD). A one-dimensional (1-D) model was proposed to predict the flux and thermal efficiency. Heat and mass transfer equations were solved numerically for the combined hydrophilic and hydrophobic layers. The membrane characteristics of the hydrophobic layer were considered for the calculation of the mass transfer coefficients, while the hydrophilic layer was ignored since it was assumed to be filled with water. However, the hydrophilic layer was taken into account during the calculations of conductive heat transfer. Therefore, the equations are different, compared to single-layer hydrophobic membranes. It was found that with the same hydrophobic membrane characteristics, the single-layer membranes performed with better flux and thermal efficiency than the dual-layer membranes. Furthermore, the improvement of flux and thermal efficiency by an addition of the hydrophilic layer has not been observed experimentally, and it is suggested that the improved performance for dual-layer membranes reported previously is due to improved permeability by using thinner and more porous hydrophobic layers that can be mechanically reinforced by the hydrophilic layer. The validation of the model was conducted by comparing the experimental results for single- and dual-layer membranes with the modelling results. The predicted flux and thermal efficiency by the modelling were within 10% error to the experimental results.

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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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