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

Molecules ◽  
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)).

Direct contact membrane distillation mechanism for high concentration NaCl solutions

Desalination ◽  
2006 ◽  
Vol 188 (1-3) ◽  
pp. 251-262 ◽  
Author(s):  
Yanbin Yun ◽  
Runyu Ma ◽  
Wenzhen Zhang ◽  
A.G. Fane ◽  
Jiding Li
Keyword(s):  
Direct Contact ◽  
Membrane Distillation ◽  
High Concentration ◽  
Direct Contact Membrane Distillation

The Role of Operating Conditions in Osmotic Distillation and Direct Contact Membrane Distillation - A Comparative Study

2006 ◽  
Vol 2 (5) ◽  
Author(s):  
V. A. Bui ◽  
M. H. Nguyen
Keyword(s):  
Comparative Study ◽  
Direct Contact ◽  
Membrane Distillation ◽  
Operating Conditions ◽  
Flux Rate ◽  
High Concentration ◽  
Osmotic Distillation ◽  
Direct Contact Membrane Distillation ◽  
Feed Temperature

This paper presents a comparative study on the role of operating conditions in osmotic distillation (OD) and direct contact membrane distillation (DCMD). Comparisons were made for lab scale OD and DCMD experiments on two types of PVDF hollow fibres under similar operating conditions for the concentration of glucose solutions from 30 to 60% (w/w) at temperatures as low as 25 to 45°C. Analysis of the results indicated that temperature was the most influencing factor for process improvement for both OD and DCMD. The flux in DCMD was improved by 3 to 4 times when feed temperature increased by 15 degrees, while this figure was nearly 3 times for OD when feed temperature increased by 20 degrees. The flow rates of the two streams played a more important role in maintaining the driving force, and consequently the flux rate, in DCMD rather than in OD. It was found that feed velocity had significant effect on DCMD performance, but insignificant in OD. Feed concentration, as the determining factor on water activity and viscosity, caused a more serious reduction of the flux rate in the high concentration range of 45-60% rather than in the dilute region of 30-40%. The effect was more significant in DCMD than in OD. The ratio of DCMD flux over that of OD ranged from 0.41 to 0.66 for PV375 when concentrating glucose solutions 30-40% w/w and from 0.35 to 0.69 for PV650 when concentrating high solid content ones. However, DCMD can overcome the disadvantages of OD being poor consumers’ perception, (due to the use of brine solution being a chemical), the potential problem of corrosion by the brine and the cost of its reconcentration.

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

Desalination ◽  
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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