Effect and mechanism of an anionic surfactant on membrane performance during direct contact membrane distillation

One of the biggest challenges for direct contact membrane distillation (DCMD) in treating wastewater from flue gas desulfurization (FGD) is the rapid deterioration of membrane performance resulting from precipitate fouling. Chemical pretreatment, such as lime-soda ash softening, has been used to mitigate the issue, however, with significant operating costs. In this study, mechanical vibration of 42.5 Hz was applied to lab-scale DCMD systems to determine its effectiveness of fouling control for simulated FGD water. Liquid entry pressure and mass transfer limit of the fabricated hollow fiber membranes were determined and used as the operational constraints in the fouling experiments so that the observed membrane performance was influenced solely by precipitate fouling. Minimal improvement of water flux was observed when applying vibration after significant (~16%) water-flux decline. Initiating vibration at the onset of the experiments prior to the exposure of foulants, however, was promising for the reduction of membrane fouling. The water-flux decline rate was reduced by about 50% when compared to the rate observed without vibration. Increasing the module packing density from 16% to 50% resulted in a similar rate of water-flux decline, indicating that the fouling propensity was not increased with packing density in the presence of vibration.

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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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