Insight into the feed/permeate flow velocity on the trade-off of water flux and scaling resistance of superhydrophobic and welding-pore fibrous membrane in membrane distillation

2020 ◽  
pp. 118883
Author(s):  
Zhigao Zhu ◽  
Wei Wang ◽  
Qianyun Zhang ◽  
Xuemei Chen
Keyword(s):  
Flow Velocity ◽  
Water Flux ◽  
Membrane Distillation ◽  
Fibrous Membrane ◽  
Trade Off ◽  
Scaling Resistance ◽  
Insight Into

scholarly journals Noni fruit’s water spot appearance on the second day of harvest: a trade-off between resistance and energy

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Tian Wu ◽  
Danyan Hu ◽  
Qingfen Wang
Keyword(s):  
Statistical Analysis ◽  
Molecular Level ◽  
Morinda Citrifolia ◽  
Transcriptome Data ◽  
Trade Off ◽  
Kegg Pathways ◽  
Available Energy ◽  
Climacteric Fruit ◽  
The Relationship ◽  
Insight Into

Abstract Background Noni (Morinda citrifolia Linn.) is a tropical tree that bears climacteric fruit. Previous observations and research have shown that the second day (2 d) after harvest is the most important demarcation point when the fruit has the same appearance as the freshly picked fruit (0 d); however, they are beginning to become water spot appearance. We performed a conjoint analysis of metabolome and transcriptome data for noni fruit of 0 d and 2 d to reveal what happened to the fruit at the molecular level. Genes and metabolites were annotated to KEGG pathways and the co-annotated KEGG pathways were used as a statistical analysis. Results We found 25 pathways that were significantly altered at both metabolic and transcriptional levels, including a total of 285 differentially expressed genes (DEGs) and 11 differential metabolites through an integrative analysis of transcriptomics and metabolomics. The energy metabolism and pathways originating from phenylalanine were disturbed the most. The upregulated resistance metabolites and genes implied the increase of resistance and energy consumption in the postharvest noni fruit. Most genes involved in glycolysis were downregulated, further limiting the available energy. This lack of energy led noni fruit to water spot appearance, a prelude to softening. The metabolites and genes related to the resistance and energy interacted and restricted each other to keep noni fruit seemingly hard within two days after harvest, but actually the softening was already unstoppable. Conclusions This study provides a new insight into the relationship between the metabolites and genes of noni fruit, as well as a foundation for further clarification of the post-ripening mechanism in noni fruit.

scholarly journals Augmenting the distillate water flux of sweeping gas membrane distillation using turbulators: A numerical investigation

2021 ◽  
pp. 101180
Author(s):  
Mahmoud Badawy Elsheniti ◽  
Mohamed O. Elbessomy ◽  
Kareem Wagdy ◽  
Osama A. Elsamni ◽  
Mahmoud M. Elewa
Keyword(s):  
Numerical Investigation ◽  
Water Flux ◽  
Membrane Distillation ◽  
Sweeping Gas

Enhanced Membrane Distillation Water Flux through Electromagnetism

2021 ◽  
pp. 108597
Author(s):  
Ibrahim Mustafa ◽  
Alibi Kilibay ◽  
Emad Alhseinat ◽  
Faisal Almarzooqi
Keyword(s):  
Water Flux ◽  
Membrane Distillation

scholarly journals Exploiting the Interplay between Liquid-Liquid Demixing and Crystallization of the PVDF Membrane for Membrane Distillation

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
N. I. M. Nawi ◽  
M. R. Bilad ◽  
N. A. H. M. Nordin ◽  
M. O. Mavukkandy ◽  
Z. A. Putra ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Water Flux ◽  
High Water ◽  
Membrane Distillation ◽  
Degree Of Crystallinity ◽  
Solution Temperature ◽  
Hydrophobic Membrane ◽  
Sem Images ◽  
Cold Temperatures ◽  
Dope Solution

Membrane distillation (MD) purifies water by transporting its vapor through a hydrophobic membrane. An ideal MD membrane poses high water flux and high fouling, scaling, and wetting resistances. In this study, we develop polyvinylidene fluoride (PVDF) membranes for MD by focusing on reduction of PVDF degree of crystallinity. We explore the roles of dope solution temperature in dictating the phase separation mechanisms as well as the structure and the performance of semicrystalline PVDF membranes. DSC spectra show that higher dope solution temperature depresses crystallinity via formation of imperfect crystal. Such findings were also supported by FTIR and XRD results. The SEM images reveal formation of spherulite-like morphology in the membrane matrices for membranes prepared from high temperature dope solutions. A good balance between solid-liquid and liquid-liquid phase separations that offers low degree of crystallinity was found at a dope solution temperature of 60°C (PVDF-60), which showed the MD flux of 18 l/m2 h (vs. 6 l/m2 h for temperature of 25°C, as a benchmark) and nearly complete salt rejection when run at hot and cold temperatures of 65°C and 25°C, respectively. The PVDF-60 shows a high wetting resistance and stable MD flux of 10.5 l/m2 h over a 50 h test for treating brine solution as the feed (70 g NaCl/l).

Senior consumers and risk/benefit trade-off in functional foods

2017 ◽  
Vol 119 (6) ◽  
pp. 1232-1246 ◽  
Author(s):  
Aina Ravoniarison
Keyword(s):  
Perceived Risk ◽  
Functional Foods ◽  
Perceived Value ◽  
Repurchase Intention ◽  
Significant Discrepancy ◽  
Trade Off ◽  
Content Type ◽  
Personal Variables ◽  
Practical Implications ◽  
Insight Into

Purpose The purpose of this paper is to examine how French senior consumers deal with duality between perceived risk and perceived value associated with functional foods (FFs) and to analyze whether the risk-value trade-off may help to derive different consumer profiles. Design/methodology/approach Data were collected from 220 senior consumers (50-70). A two-step clustering analysis was carried out on factor scores of perceived value and perceived risk. Discriminant analysis was then employed to verify the classification reliability, and analysis of variance was performed to profile the clusters on the basis of additional variables. Findings Four distinctive profiles of FF senior consumers were identified. Significant differences were found to be attributed to personality traits. Interestingly, the “Trustful enthusiasts” and the “Ambivalents” consumers do not differ in their repurchase intention, despite a significant discrepancy in risk perception. Practical implications The study is an opportunity to offer a segmentation of this attractive growing target of health-enhancing products. The typology can help the practitioners to find out a new valuable scope of messages to better communicate to elderly market. Originality/value The research seeks to contribute to the existing knowledge on seniors’ nutrition-related behavior, by proposing a segmentation still lacking in research works. Since FF perceived value appears to be multidimensional and not only utilitarian, the study provides a new insight into the experiential approach of health-enhancing eating. Also, it shows how the differences between FF consumers could be attributed to certain personal variables.

Scaling resistance by fluoro-treatments: The importance of wetting states

2022 ◽  
Author(s):  
Li Liu ◽  
Laura Charlton ◽  
Yanqing Song ◽  
Tao Li ◽  
Xue-Mei Li ◽  
...  
Keyword(s):  
High Salinity ◽  
Membrane Distillation ◽  
Separation Process ◽  
Porous Membranes ◽  
Thermally Driven ◽  
Scaling Resistance

Membrane distillation is a thermally driven separation process using hydrophobic, porous membranes. Among various problems faced by membrane distillation, scaling remains an unresolved challenge in treating streams of high salinity....

Removal of high concentration Congo red by hydrophobic PVDF hollow fiber composite membrane coated with a loose and porous ZIF-71PVDF layer through vacuum membrane distillation

2020 ◽  
pp. 152808372096707
Author(s):  
Hongbin Li ◽  
Wenying Shi ◽  
Qiyun Du ◽  
Shoufa Huang ◽  
Haixia Zhang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Hollow Fiber ◽  
Congo Red ◽  
Fiber Composite ◽  
Water Flux ◽  
Membrane Distillation ◽  
Feed Flow Rate ◽  
High Concentration ◽  
Operation Conditions ◽  
Feed Temperature

Although membrane distillation (MD) technology has the outstanding advantages of almost 100% solute retention and mild operation conditions, its further development is limited by low permeate flux. In order to solve the problem, the improvement of membrane hydrophobicity becomes one of the effective solutions. In this study, a loose and porous hydrophobic zeolitic imidazolate frameworks-71 (ZIF-71)/polyvinylidene fluoride (PVDF) coating layer was composited on the outside surface of PVDF hollow fiber support membrane by the dilute solution coating to enhance membrane hydrophobicity. The prepared hollow fiber composite (HFC) membranes were employed to remove high concentration Congo red (CR) through VMD. The effects of different operation conditions including the dye concentration, feed temperature, vacuum pressure and feed flow rate on CR rejection and permeate water flux were investigated. In the variation range of operating conditions, all the CR rejection of the PVDF HFC membranes shows a slight change and remains above 99.9%. Under the optimal operation conditions including dye concentration 600 mg·L−1, vacuum pressure 31.325 kPa, feed temperature 60°C and feed flow rate 50 L·h−1, HFC membrane exhibit a permeate water flux of 13.15 kg·m−2·h−1. HFC membrane suffers dye fouling during the continuous dye filtration for 100 h. The fouling mechanism was proposed and a combined cleaning way including forward washing, back flushing and chemical desorption has been proved to be effective in recovering membrane water flux.

scholarly journals Relationship between surface hydrophobicity and flux for membrane separation

RSC Advances ◽  
2020 ◽  
Vol 10 (66) ◽  
pp. 40043-40046
Author(s):  
Gil-Seon Kang ◽  
Youngbin Baek ◽  
Ji-Beom Yoo
Keyword(s):  
High Performance ◽  
Membrane Separation ◽  
Water Flux ◽  
Surface Hydrophobicity ◽  
Membrane Surfaces ◽  
Hydrophobic Pore ◽  
Hydrophilic Membrane ◽  
Insight Into

This study demonstrated that hydrophobic pore surfaces and hydrophilic membrane surfaces are more favorable in enhancing water flux, providing an important insight into the development of high performance membranes.

scholarly journals The Water Flux Dynamic in a Hybrid Forward Osmosis-Membrane Distillation for Produced Water Treatment

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 225
Author(s):  
Normi Izati Mat Nawi ◽  
Muhammad Roil Bilad ◽  
Ganeswaran Anath ◽  
Nik Abdul Hadi Nordin ◽  
Jundika Candra Kurnia ◽  
...  
Keyword(s):  
Water Treatment ◽  
Produced Water ◽  
Water Flux ◽  
Forward Osmosis ◽  
Membrane Distillation ◽  
Flux Dynamics ◽  
Flux Dynamic ◽  
Produced Water Treatment ◽  
Dynamic Hybrid ◽  
Membrane Wetting

Standalone membrane distillation (MD) and forward osmosis (FO) have been considered as promising technologies for produced water treatment. However, standalone MD is still vulnerable to membrane-wetting and scaling problems, while the standalone FO is energy-intensive, since it requires the recovery of the draw solution (DS). Thus, the idea of coupling FO and MD is proposed as a promising combination in which the MD facilitate DS recovery for FO—and FO acts as pretreatment to enhance fouling and wetting-resistance of the MD. This study was therefore conducted to investigate the effect of DS temperature on the dynamic of water flux of a hybrid FO–MD. First, the effect of the DS temperature on the standalone FO and MD was evaluated. Later, the flux dynamics of both units were evaluated when the FO and DS recovery (via MD) was run simultaneously. Results show that an increase in the temperature difference (from 20 to 60 °C) resulted in an increase of the FO and MD fluxes from 11.17 ± 3.85 to 30.17 ± 5.51 L m−2 h−1, and from 0.5 ± 0.75 to 16.08 L m−2 h−1, respectively. For the hybrid FO–MD, either MD or FO could act as the limiting process that dictates the equilibrium flux. Both the concentration and the temperature of DS affected the flux dynamic. When the FO flux was higher than MD flux, DS was diluted, and its temperature decreased; both then lowered the FO flux until reaching an equilibrium (equal FO and MD flux). When FO flux was lower than MD flux, the DS was concentrated which increased the FO flux until reaching the equilibrium. The overall results suggest the importance of temperature and concentration of solutes in the DS in affecting the water flux dynamic hybrid process.

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