scholarly journals Improved Surface Functional and Photocatalytic Properties of Hybrid ZnO-MoS2-Deposited Membrane for Photocatalysis-Assisted Dye Filtration

Membranes ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 106 ◽  
Author(s):  
Saranya Rameshkumar ◽  
Rory Henderson ◽  
Ramesh Babu Padamati
Keyword(s):  
Membrane Filtration ◽  
Dye Removal ◽  
Dye Degradation ◽  
Irradiation Time ◽  
Complete Removal ◽  
Membrane Resistance ◽  
Bandgap Energy ◽  
Permeate Flux ◽  
Synergistic Mechanism ◽  
Surfactant Assisted

The synergistic mechanism of photocatalytic-assisted dye degradation has been demonstrated using a hybrid ZnO-MoS2-deposited photocatalytic membrane (PCM). Few layers of MoS2 sheets were produced using the facile and efficient surfactant-assisted liquid-phase exfoliation method. In this process, hydrophilic moieties of an anionic surfactant were adsorbed on the surface of MoS2, which aided exfoliation and promoted a stable dispersion due to the higher negative zeta potential of the exfoliated MoS2 sheets. Further, the decoration of ZnO on the exfoliated MoS2 sheets offered a bandgap energy reduction to about 2.77 eV, thus achieving an 87.12% degradation of methylene blue (MB) dye within 15 min of near UV-A irradiation (365 nm), as compared with pristine ZnO achieving only 56.89%. The photocatalysis-enhanced membrane filtration studies on the ZnO-MoS2 PCM showed a complete removal of MB dye (~99.95%). The UV-assisted dye degradation on the ZnO-MoS2 PCM offered a reduced membrane resistance, with the permeate flux gradually improving with the increase in the UV-irradiation time. The regeneration of the active ZnO-MoS2 layer also proved to be quite efficient with no compromise in the dye removal efficiency.

Anionic surfactant assisted copper hydroxide for toxic dye removal from wastewater

2021 ◽  
pp. 111310
Author(s):  
S.P. Keerthana ◽  
R. Yuvakkumar ◽  
P. Senthil Kumar ◽  
G. Ravi ◽  
Dhayalan Velauthapillai
Keyword(s):  
Anionic Surfactant ◽  
Dye Removal ◽  
Copper Hydroxide ◽  
Surfactant Assisted

Concentration and Desalination of Protein Derived from Tuna Cooking Juice by Nanofiltration

2013 ◽  
Vol 65 (4) ◽  
Author(s):  
Muhammadameen Hajihama ◽  
Wirote Youravong
Keyword(s):  
Membrane Filtration ◽  
Protein Concentration ◽  
Protein Hydrolysate ◽  
Salt Content ◽  
Cross Flow ◽  
Transmembrane Pressure ◽  
Permeate Flux ◽  
Batch Mode ◽  
Additional Process ◽  
Canning Industry

Tuna cooking juice is a co-product of tuna canning industry. It riches in protein, currently used for production of feed meal as well as protein hydrolysate. The finish products are usually in the form of concentrate, produced by evaporation process. However, evaporation is energy consumable process and the salt content level of the concentrate is often over the standard, thus required additional process for lowering salt content e.g. crystallization. The use of membrane technology, therefore, is of interest, since it required less energy and footprint compared with evaporation and is also able to reduce salt content of the concentrate. The aim of this study were to employ and select the membrane filtration process, and optimize the operating condition for protein concentration and desalination of tuna cooking juice. The results indicated that nanofiltration (NF) was more suitable than the ultrafiltration (UF) process, regarding the ability in protein recovery and desalination. The NF performance was evaluated in terms of permeation flux and protein and salt retentions. The protein and salt rejections of NF were 96 % and 5 %, respectively. The permeate flux(J) increased as transmembrane pressure (TMP) or cross flow rate (CFR) increased and the highest flux was obtained at TMP of 10 bar and CFR of 800 L/h. Operating with batch mode, the permeate flux was found to decrease as protein concentration increased, and at volume concentration factor about 4, the protein concentration  about 10% while salt removal was aproximately 70 % of the initial value. This work clearly showed that NF was successfully employed for concentration and desalination of protein derived from tuna cooking juice.

Facile Synthesis of Unique Bismuth Vanadate Nano-Knitted Hollow Cage and its Application in Environmental Remediation

2019 ◽  
Vol 74 (3) ◽  
pp. 259-263 ◽  
Author(s):  
M. Shamshi Hassan
Keyword(s):  
Environmental Remediation ◽  
Dye Degradation ◽  
High Surface ◽  
High Surface Area ◽  
Bismuth Vanadate ◽  
Bandgap Energy ◽  
Blue Dye ◽  
X Ray ◽  
Photodegradation Efficiency ◽  
Hollow Nanostructure

AbstractHierarchical bismuth vanadate (BiVO4) nano-knitted hollow cages have been synthesized by simple hydrothermal method and characterized by scanning electron microscopy, x-ray diffraction, energy-dispersive x-ray spectrometer, Fourier transform infrared, UV-Vis, and Raman. The photodegradation efficiency of BiVO4 nanocage for universally used methylene blue dye. The BiVO4 hollow nanostructure demonstrated better photocatalytic competence in dye degradation as compared to the commercial TiO2 powders (P25). The excellent dye degradation can be certified to the high crystallisation of monoclinic BiVO4 and hollow nanostructure, which leads to high surface area and small bandgap energy of 2.44 eV.

Analysis of Primary Degradation and Decolourization of Dyes in Water by an H2O2/UV Advanced Oxidation Process

2008 ◽  
Vol 11 (3) ◽  
Author(s):  
Amaia Menendez ◽  
Jose Ignacio Lombraña ◽  
Ana de Luis
Keyword(s):  
Dye Removal ◽  
Advanced Oxidation Process ◽  
Rhodamine 6G ◽  
Dye Degradation ◽  
Water Solution ◽  
Synthetic Dyes ◽  
Dye Wastewater ◽  
First Order ◽  
Textile Dyeing ◽  
Colour Photography

AbstractSynthetic dyes are extensively used in textile dyeing, paper printing, colour photography, pharmaceuticals, food, cosmetics and other industries. In spite of their diversity there are a certain number of properties common to many dye compounds, such as aromatic constitution, chromophore groups and others. Similarly to other dyes and due to the formation of colour intermediates, in the case of Rhodamine 6G colour capacity is maintained in the initial steps of dye degradation. For this reason in the degradation of a dye it is necessary to distinguish between two processes that take place simultaneously: dye removal and decolourization. This study was conducted by using a water solution of 50 mg/L of Rhodamine 6G (Rh-6G), as a model of a dye wastewater, in the hydrogen peroxide/UV system. The kinetic model proposed in this paper for the removing of Rh- 6G is a sequential first-order reaction. This model describes acceptably the changes in two kinds of compound for a wide interval of H

scholarly journals Cold Sterilization of Coconut Water Using Membrane Filtration: Effect of Membrane Property and Operating Condition

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
A. Laorko ◽  
Z. Li ◽  
W. Youravong ◽  
S. Tongjitpakdee ◽  
S. Chantachum
Keyword(s):  
Pore Size ◽  
Thermal Processing ◽  
Membrane Filtration ◽  
Coconut Water ◽  
Microbiological Analysis ◽  
Permeate Flux ◽  
Fouling Resistance ◽  
Membrane Pore ◽  
Uf Membranes

Coconut water has been considered as a nutritional, refreshing and highly isotonic beverage with delicate aroma and flavor. In food sterilization technique, thermal processing, however tends to reduce these beneficial properties especially estrogen hormone and flavor. To overcome this limitation, this study therefore aimed to clarified and sterilized coconut water using non–thermal processing, membrane filtration. Hollow fiber microfiltration (MF) membrane with pore size of 0.1 and 0.2 μm and ultrafiltration (UF) membrane with molecular weight cut–off (MWCO) of 100 and 30 kDa were used. The effect of membrane pore size and MWCO on quality of clarified juice, permeate flux and fouling were studied. It was found that fresh coconut water and clarified coconut water obtained from MF and UF did not show difference in pH, total soluble solid, reducing sugar, estrogen hormone and minerals including calcium, magnesium, phosphorus, potassium and sodium. The results from microbiological analysis of the clarified coconut water showed that sterilized of coconut water was obtained using either MF or UF membranes. This microbiological quality of clarified coconut water was met the Thai legislation for juice and drinks. The permeate flux of MF was much higher than those of UF while the fouling resistance of UF membrane was much higher than those of MF membrane. The permeate flux of membrane with pore size of 0.1 £gm was slightly lower than that of membrane with pore size of 0.2 μm. The results also indicated that the major fouling of both MF and UF membranes was reversible. The irreversible fouling resistance of 0.1 μm membrane was the lowest and most of this irreversible fouling was external irreversible fouling, formed on the membrane surface. According to these results, it could be concluded that 0.1 μm membrane was the most suitable membrane for clarification and sterilization of coconut water. In addition, the effects of TMP, cross flow velocity (CFV) and the % recovery on permeate flux in batch concentration mode were also studied. It was found that the permeate flux of 0.1 μm membrane was significantly increased with increasing CFV and decreased as % recovery increased. These results suggested that permeate flux during MF of coconut water was dependent on reversible fouling and could be improved by using hydrodynamic modification techniques.

scholarly journals Low- and High-Pressure Membrane Separation in the Production of Process Water for Coke Quenching

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 937
Author(s):  
Anna Trusek ◽  
Maciej Wajsprych ◽  
Andrzej Noworyta
Keyword(s):  
High Pressure ◽  
Membrane Filtration ◽  
Membrane Separation ◽  
Coke Oven ◽  
Industrial Plant ◽  
Operating Pressure ◽  
Permeate Flux ◽  
Final Treatment ◽  
Stage System ◽  
Pressure Plant

Although the time for operating mines and coking plants in many countries is coming to an end due to climate change, we must still ensure that the pollution generated by this source of the economy is minimized. Despite the several stages of treatment of the coke-oven effluent, completed with nitrification and denitrification processes preceding final sedimentation, the stream obtained does not meet the requirements of water for coke quenching. That is why the stream after biodegradation and sedimentation was treated on membrane units to ensure water reusing in the coking plant. As the subjected stream contained both solid and dissolved pollutants, a two-stage system was proposed: low- and high-pressure membrane filtration. Industrial modules were tested on pilot units operating under industrial plant conditions. In the case of the ultrafiltration process, all the tested ultrafiltration modules fulfilled the primary task. All of them separated almost completely the turbidities present in the stream, which would have disturbed the operation of the high-pressure plant. Considering the decrease in permeate flux and the possibility of cleaning, a PCI membrane made of PVDF tubes with a diameter of 12.5 mm and pore size of 20 μm was selected. Regarding the high-pressure membrane filtration, the reverse osmosis membrane was significantly better in the removal efficiency of both organic and inorganic dissolved substances. An operating pressure of 3 MPa was chosen for the system. Hence, membrane processes, which are not used as stand-alone treatment units for coke-oven effluents, function well as a final treatment stage.

Abrupt Change of Bandgap Energy in Quantum System of Nanolayer on Silicon Surface

2020 ◽  
Author(s):  
Wei-Qi Huang ◽  
Shi-Rong Liu ◽  
Zi-Lin Wang ◽  
Cui-Fen Chen ◽  
Ke Wang ◽  
...  
Keyword(s):  
Electron Beam ◽  
Quantum System ◽  
Electron Beam Irradiation ◽  
Abrupt Change ◽  
Irradiation Time ◽  
Bandgap Energy ◽  
Main Role ◽  
Simulating Calculation ◽  
Change Effect ◽  
Simulated Calculation

Abstract In the quantum system of nanolayer (NL) on silicon, the bandgap energy obviously increases with decreasing thickness of NL, in which the quantum confinement (QC) effect plays a main role. In simulating calculation, the QC effect has been exhibited as the thickness of Si NL changes along with (100), (110) and (111) direction respectively. And the simulation result demonstrated that the direct bandgap can be obtained as the NL with (001) direction is thinner than 10nm on Si surface. However, it is discovered in the simulated calculation that the QC effect disappears as the NL thickness arrives at size of monoatomic layer, in which its bandgap sharply deceases, where the abrupt change effect in bandgap energy occurs near idea 2D-layer. In experiment, we fabricated the Si NL structure by using electron beam irradiation and pulsed laser deposition methods, in which a novel way was used to control the NL thickness by modulating irradiation time of electron beam. The new effect should have a good application on optic-electronic chip of silicon.

Permeate flux hysteresis with transmembrane pressure in the gel controlling membrane filtration

2020 ◽  
Vol 264 ◽  
pp. 109689
Author(s):  
Sourav Mondal ◽  
Agata Egea-Corbacho ◽  
Carmela Conidi ◽  
Alfredo Cassano ◽  
Sirshendu De
Keyword(s):  
Membrane Filtration ◽  
Transmembrane Pressure ◽  
Permeate Flux

scholarly journals Oily Wastewater Treatment Using Polyamide Thin Film Composite Membrane Technology

Membranes ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 84 ◽  
Author(s):  
Sarah Elhady ◽  
Mohamed Bassyouni ◽  
Ramadan A. Mansour ◽  
Medhat H. Elzahar ◽  
Shereen Abdel-Hamid ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Membrane Filtration ◽  
Edible Oil ◽  
Oily Wastewater ◽  
Permeate Flux ◽  
Treatment Unit ◽  
Thin Film Composite ◽  
Ro Membrane ◽  
Pre Treatment ◽  
Oil Wastewater

In this study, polyamide (PA) thin film composite (TFC) reverse osmosis (RO) membrane filtration was used in edible oil wastewater emulsion treatment. The PA-TFC membrane was characterized using mechanical, thermal, chemical, and physical tests. Surface morphology and cross-sections of TFCs were characterized using SEM. The effects of edible oil concentrations, average droplets size, and contact angle on separation efficiency and flux were studied in detail. Purification performance was enhanced using activated carbon as a pre-treatment unit. The performance of the RO unit was assessed by chemical oxygen demand (COD) removal and permeate flux. Oil concentration in wastewater varied between 3000 mg/L and 6000 mg/L. Oily wastewater showed a higher contact angle (62.9°) than de-ionized water (33°). Experimental results showed that the presence of activated carbon increases the permeation COD removal from 94% to 99%. The RO membrane filtration coupled with an activated carbon unit of oily wastewater is a convenient hybrid technique for removal of high-concentration edible oil wastewater emulsion up to 99%. Using activated carbon as an adsorption pre-treatment unit improved the permeate flux from 34 L/m2hr to 75 L/m2hr.

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