Experimental and Modelling of Aqueous Radioactive Waste Treatment by Ultrafiltration

Ultrafiltration of untreated and pretreated aqueous radioactive wastes was conducted using a spiral-wound polysulphonamide membrane. The influence of process factors on its performances was experimental studied and predicted. Permeate volumetric flux and permeate total suspended solids (TSS) were measured at different values of feed flow rate (7 and 10 m3/h), operating pressure (0.1-0.4 MPa), and feed TSS (15 and 60 mg/L). Permeate flux (42-200 L/(m2�h)) increased with feed flow rate and operating pressure as well as it decreased with an increase in feed TSS, whereas permeate TSS (0.1-33.2 mg/L) exhibited an opposite trend. A 23 factorial plan was used to establish correlations between dependent and independent variables of ultrafiltration process.

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A Comparison Study of Brine Desalination using Direct Contact and Air Gap Membrane Distillation

Journal of Engineering ◽

10.31026/j.eng.2019.11.04 ◽

2019 ◽

Vol 25 (11) ◽

pp. 47-54

Author(s):

Ahmed Shamil Khalaf ◽

Asrar Abdullah Hassan

Keyword(s):

Flow Rate ◽

Direct Contact ◽

Polyvinylidene Fluoride ◽

Membrane Distillation ◽

Air Gap ◽

Feed Flow Rate ◽

Permeate Flux ◽

Air Gap Membrane Distillation ◽

Flat Sheet ◽

Feed Temperature

Membrane distillation (MD) is a hopeful desalination technique for brine (salty) water. In this research, Direct Contact Membrane Distillation (DCMD) and Air Gap Membrane Distillation (AGMD) will be used. The sample used is from Shat Al –Arab water (TDS=2430 mg/l). A polyvinylidene fluoride (PVDF) flat sheet membrane was used as a flat sheet form with a plate and frame cell. Several parameters were studied, such as; operation time, feed temperature, permeate temperature, feed flow rate. The results showed that with time, the flux decreases because of the accumulated fouling and scaling on the membrane surface. Feed temperature and feed flow rate had a positive effect on the permeate flux, while permeate temperature had a reverse effect on permeate flux. It is noticeable that the flux in DCMD is greater than AGMD, at the same conditions. The flux in DCMD is 10.95LMH, and that in AGMD is 7.14 LMH. In AGMD, the air gap layer made a high resistance. Here the temperature transport reduces in the permeate side of AGMD due to the air gap resistance. The heat needed for AGMD is lower than DCMD, this leads to low permeate flux because the temperature difference between the two sides is very small, so the driving force (vapor pressure) is low.

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Performance Investigation of O-Ring Vacuum Membrane Distillation Module for Water Desalination

Journal of Chemistry ◽

10.1155/2016/9378460 ◽

2016 ◽

Vol 2016 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Adnan Alhathal Alanezi ◽

H. Abdallah ◽

E. El-Zanati ◽

Adnan Ahmad ◽

Adel O. Sharif

Keyword(s):

Flow Rate ◽

Membrane Distillation ◽

Membrane Module ◽

Water Desalination ◽

Feed Flow Rate ◽

Permeate Flux ◽

Vacuum Degree ◽

Flat Sheet ◽

Vacuum Membrane Distillation ◽

Feed Temperature

A new O-ring flat sheet membrane module design was used to investigate the performance of Vacuum Membrane Distillation (VMD) for water desalination using two commercial polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) flat sheet hydrophobic membranes. The design of the membrane module proved its applicability for achieving a high heat transfer coefficient of the order of 103 (W/m2 K) and a high Reynolds number (Re). VMD experiments were conducted to measure the heat and mass transfer coefficients within the membrane module. The effects of the process parameters, such as the feed temperature, feed flow rate, vacuum degree, and feed concentration, on the permeate flux have been investigated. The feed temperature, feed flow rate, and vacuum degree play an important role in enhancing the performance of the VMD process; therefore, optimizing all of these parameters is the best way to achieve a high permeate flux. The PTFE membrane showed better performance than the PVDF membrane in VMD desalination. The obtained water flux is relatively high compared to that reported in the literature, reaching 43.8 and 52.6 (kg/m2 h) for PVDF and PTFE, respectively. The salt rejection of NaCl was higher than 99% for both membranes.

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Factors Influencing Hardness of a Coating Material for Coating a Machine Component

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.821.294 ◽

2019 ◽

Vol 821 ◽

pp. 294-300

Author(s):

Charnnarong Saikaew

Keyword(s):

Wear Resistance ◽

Flow Rate ◽

Rate Ratio ◽

Flow Rate Ratio ◽

Machine Component ◽

Operating Pressure ◽

Operating Condition ◽

Significant Process ◽

Process Factors ◽

Dc Current

This work investigated the influences of DC current, pressure and N2 to Ar gas flow rate on hardness of a TiN hard coating material for coating a fishing net-weaving machine component of a fishing net-weaving machine, namely upper hook. The target of this study was to maximize the hardness of TiN coated upper hook in order to maximize the corresponding wear resistance. Three process factors including DC current, operating pressure and N2 to Ar flow rate ratio were simultaneously investigated using the factorial design with replicates at the center point of the three factors method. Analysis of variance was used to investigate the effect of the three factors on the hardness of the TiN coated upper hook and the contour plots based on empirical model were plotted to obtain an appropriate operating condition of the statistically significant process factors with maximizing hardness value leading to the wear resistance of the upper hook. The results showed that the operating pressure and the N2 to Ar flow rate ratio and interaction among the three process factors significantly affected the average hardness at the level of significance of 0.05. Finally, an appropriate operating condition of the significant process factors was obtained at the higher levels of the operating pressure and the N2 to Ar flow rate ratio.

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The optimization of spray-drying process for the development of apricot powder using response surface methodology

British Food Journal ◽

10.1108/bfj-07-2021-0727 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Omar Bashir ◽

Syed Zameer Hussain ◽

Tawheed Amin ◽

Nusrat Jan ◽

Gousia Gani ◽

...

Keyword(s):

Response Surface ◽

Spray Drying ◽

Air Temperature ◽

Flow Rate ◽

Gum Arabic ◽

Feed Flow Rate ◽

Drying Process ◽

Content Type ◽

Independent Variables ◽

Pharmacological Significance

PurposeApricots are not only nutritionally-rich but also possess pharmacological significance owing to their high antioxidant activity, and they are rich in vitamins, fibers, bioactive phytochemicals and minerals. Because of its immense organoleptic characteristics, apricot juice (AJ) is well accepted; however, it has a limited shelf-life, thereby demanding it to be converted into other shelf-stable form. One of the approaches is converting this juice into dehydrated powder. Amongst the various dehydration techniques available, spray drying is usually preferred; however, it involves the use of several independent variables, which need to be optimized, thus prompting to optimize the process to obtain spray dried apricot powder (SDAP) with improved quality.Design/methodology/approachThe spray-drying process of apricot juice was done using the response surface approach. The process variables included the inlet air temperature of 135–220°C, gum arabic concentration of 4–25%, feed flow rate of 124–730 mL/h, feed total soluble solids (TSS) of 10-30°Brix and atomization speed of 11,400–28,000 rpm. The dependent responses were powder yield, hygroscopicity, solubility, moisture content, carotenoids (CT), ascorbic acid (AA), radical scavenging activity (RSA), lightness, wettability, bulk density, particle density and porosity.FindingsAmongst all independent variables, inlet air temperature had most predominant impact on all the investigated responses. The optimum processing conditions for development of apricot powder with optimum quality were 190°C inlet air temperature, 18.99% gum arabic, 300.05 mL/h feed flow rate, 24°Brix feed TSS and 17433.41 rpm atomization speed. The experimental values were found to be in agreement with the predicted values, indicating the suitability of models in predicting optimizing responses of apricot powder. Flowability as Carr's index (CI) (22.36 ± 1.01%) suggests fair flow of powder. Glass transition temperature of powder was 57.85 ± 2.03°C, which is much higher than that of ambient, suggesting its better shelf stability.Originality/valueTo the best of author's knowledge, very limited or very few studies have been carried out on the spray-drying process for the manufacture of SDAP. The results of this investigation will open up new horizons in the field of food industry in the Union Territory of Jammu and Kashmir, India or elsewhere in the apricot-growing areas of India.

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Multi-objective optimization of microfiltration of baker’s yeast using genetic algorithm

Acta periodica technologica ◽

10.2298/apt1748211l ◽

2017 ◽

pp. 211-220 ◽

Cited By ~ 2

Author(s):

Natasa Lukic ◽

Marija Bozin-Dakic ◽

Jovana Grahovac ◽

Jelena Dodic ◽

Aleksandar Jokic

Keyword(s):

Genetic Algorithm ◽

Genetic Algorithms ◽

Energy Consumption ◽

Flow Rate ◽

Transmembrane Pressure ◽

Feed Flow Rate ◽

Multi Objective Optimization ◽

Permeate Flux ◽

Multi Objective ◽

Reduction Of Energy Consumption

This paper presents a multi-objective optimization model by applying genetic algorithm in order to search for optimal operating parameters of microfiltration of baker?s yeast in the presence of static mixer as a turbulence promoter. The operating variables were the suspension concentration, transmembrane pressure, and feed flow rate. Two conflicting objective functions, maximizing the permeate flux and maximizing the reduction of energy consumption, were considered. This multi-objective optimization problem was solved by using the elitist non-dominated sorting genetic algorithm in the Matlab R2015b software. The Pareto fronts along with the process decision variables correspondding to the optimal solutions were obtained. It was found that lower suspension concentrations (2-4.5 g/L), feed flow rate in the range 109-127 L/h, and transmembrane pressure of 1 bar were the optimal process parameters which yielded maximum permeate flux (177-191 L/(m2h)) and maximum reduction of energy consumption (44-50%). Finally, the results were compared with the previously published results obtained by applying desirability function approach. Given that genetic algorithms have generated multiple solutions in a single optimization run, the study proved that genetic algorithms are preferable to classical optimization methods.

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A Systematic Framework for Optimizing a Sweeping Gas Membrane Distillation (SGMD)

Membranes ◽

10.3390/membranes10100254 ◽

2020 ◽

Vol 10 (10) ◽

pp. 254

Author(s):

Nawras N. Safi ◽

Salah. S. Ibrahim ◽

Nasser Zouli ◽

Hasan Shaker Majdi ◽

Qusay F. Alsalhy ◽

...

Keyword(s):

Flow Rate ◽

Gas Flow ◽

Membrane Distillation ◽

Feed Flow Rate ◽

Permeate Flux ◽

Gas Flow Rate ◽

Feed Concentration ◽

Sweeping Gas ◽

Feed Temperature ◽

Systematic Framework

The present work has undertaken a meticulous glance on optimizing the performance of an SGMD configuration utilized a porous poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) membrane. This was carried out by conducting a systematic framework for investigating and optimizing the pertinent parameters such as sweeping gas flow rate, feed temperature, feed concentration and feed flow rate on the permeate flux. For this purpose, the Taguchi method and design of experiment techniques were harnessed to statistically determine optimum operational conditions. Besides that, a comprehensive surface and permeation characterization was conducted against the hand-made membranes. Results showcased that the membrane performance was ultimately controlled by the feed temperature and was nearly (~680) % higher when the temperature raised from 45 to 65 °C. Also, to a lesser extent, the system was dominated by the feed flow rate. As the adopted feed flow rate increases (from 0.2 to 0.6 L/min), around 47.5% increment was bestowed on water permeability characteristics. In contra, 34.5% flux decline was witnessed when higher saline feed concentration (100 g/L) was utilized. In the meantime, with raising the sweeping gas flow rate (from 120 to 300 L/h), the distillate was nearly 129% higher. Based on Taguchi design, the maximum permeate flux (17.3 and 17 kg/m2·h) was secured at 35 g/L, 0.4 L/min, 65 °C and 300 L/h, for both commercial and prepared membranes, respectively.

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Machine Learning Models Applied to Manage the Operation of a Simple SWRO Desalination Plant and Its Application in Marine Vessels

Water ◽

10.3390/w13182547 ◽

2021 ◽

Vol 13 (18) ◽

pp. 2547

Author(s):

Graciliano Nicolás Marichal Plasencia ◽

Jorge Camacho-Espino ◽

Deivis Ávila Prats ◽

Baltasar Peñate Suárez

Keyword(s):

Machine Learning ◽

Flow Rate ◽

Machine Learning Techniques ◽

Support Vector ◽

Operating Pressure ◽

Feed Flow Rate ◽

Desalination Plant ◽

Learning Techniques ◽

Desalination Plants ◽

Marine Vessels

In this work, two machine learning techniques, specifically decision trees (DTs) and support vector machines (SVMs), were applied to optimize the performance of a seawater reverse osmosis (SWRO) desalination plant with a capacity of 100 m3 per day. The input variables to the system were seawater pH, seawater conductivity, and three requirements: permeate flow rate, permeate conductivity, and total energy consumed by the desalination plant. These requirements were decided based on a cost function that prioritizes the water needs in a vessel and the maximum possible energy savings. The intelligent system modifies the actuators of the plant: feed flow rate control and high-pressure pump (HPP) operating pressure. This tool is proposed for the optimal use of desalination plants in marine vessels. Although both machine learning techniques output satisfactory results, it was concluded that the DTs technique (HPP pressure: root mean square error (RMSE) = 0.0104; feed flow rate: RMSE = 0.0196) is more accurate than SVMs (HPP pressure: RMSE = 0.0918; feed flow rate: RMSE = 0.0198) based on the metrics used. The final objective of the paper is to extrapolate the implementation of this smart system to other shipboard desalination plants and optimize their performance.

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Performance of Air Gap Membrane Distillation Unit for Water Desalination

Volume 6A: Energy ◽

10.1115/imece2014-36031 ◽

2014 ◽

Cited By ~ 3

Author(s):

Atia E. Khalifa ◽

Dahiru U. Lawal ◽

Mohamed A. Antar

Keyword(s):

Flow Rate ◽

Membrane Distillation ◽

Air Gap ◽

Water Desalination ◽

Feed Water ◽

Feed Flow Rate ◽

Permeate Flux ◽

Air Gap Membrane Distillation ◽

Gap Width ◽

Feed Temperature

Due to water scarcity in the Arabic gulf region, water desalination technologies are considered extremely important. The present work represents a fundamental study on the effect of basic operating and design variables on the flux of an air gap membrane distillation (AGMD) unit for water desalination. The flat sheet, channeled air gap membrane distillation module was designed and manufactured locally. The effect of feed flow rate, feed temperature, coolant water temperature, the air gap width, and the water salinity on the module flux are investigated. Analytical model for heat and mass transfer is used to predict the flux and the model results are compared to the experimental ones. Results showed that the technique has good potential to be used for water desalination. The permeate flux is increased by increasing feed flow rate, feed temperature, decreasing the air gap width, decreasing coolant temperature, and decreasing salinity of feed water. For a given feed flow rate, the width of the air gap and the feed water temperature are found to be the most effective parameters in increasing the distillate flux. Predicting the permeate flux with analytical models for heat and mass transfer showed good agreement with experimental results.

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THE EFFECT OF OPERATING CONDITIONS ON CRITICAL FLUX AND REVERSIBLE FOULING IN MEMBRANE FILTRATION USING GAS SPARGING TECHNIQUE

Jurnal Sains dan Teknologi Reaksi ◽

10.30811/jstr.v1i2.58 ◽

2016 ◽

Vol 1 (2) ◽

Author(s):

Harunsyah Harunsyah ◽

Nik Meriam Sulaiman

Keyword(s):

Flow Rate ◽

Membrane Filtration ◽

Membrane System ◽

Operating Conditions ◽

Transmembrane Pressure ◽

Feed Flow Rate ◽

Permeate Flux ◽

Critical Flux ◽

Gas Sparging ◽

Cake Layer

Gas sparging method utilizing injection of nitrogen gas was employed during the ultrafiltration of the natural rubber effluent (latex serum). The objective of this research was to investigate the effect of gas sparging on the critical flux and the observed reversible cake layer resistance during the ultrafiltration of skim latex serum. Experiments were conducted using a 100 kDa MWCO tubular membrane (PCI Membrane System) mounted vertically. The effect of operating parameters, such as feed flow rate, concentration and transmembrane pressure were investigated. The results showed that when the feed flow rate was increased, the permeate was correspondingly increased and the reversible cake resistance decreased. In this research a feed flow rate of 1400 ml/min and transmembrane pressure of 13.00 psig resulted in the maximum total permeate flux of 70.80 L/m2h. Results from this study obtained so far showed that the use of gas sparging has been able to increase total permeate flux between 8.3% and 145.3% compared to non-gas sparged condition. Critical flux occurrence was increased to 82.63% above the value obtained for non-sparged condition and applied transmembrane pressure can be reduced to 2.4% of the non-gas sparged condition.Keyword: skim latex serum, reversible fouling, gas sparged, critical flux

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Management of Dairy Waste in the Sonoran Desert Using Constructed Wetland Technology

Water Science & Technology ◽

10.2166/wst.1999.0136 ◽

1999 ◽

Vol 40 (3) ◽

pp. 57-65 ◽

Cited By ~ 6

Author(s):

Martin M. Karpiscak ◽

Robert J. Freitas ◽

Charles P. Gerba ◽

Luis R. Sanchez ◽

Eylon Shamir

Keyword(s):

Sonoran Desert ◽

Suspended Solids ◽

Waste Treatment ◽

Oxygen Demand ◽

Dairy Wastewater ◽

Chemical Parameters ◽

Treatment Facility ◽

Physical Chemical ◽

Scirpus Validus ◽

Surface Wetland

An integrated wastewater treatment facility, consisting of upper (solids separators, anaerobic lagoons, and aerobic ponds) and lower (wetland cells) subsystems, has been built to replace the lagoon at a dairy in Arizona, USA. The collection sump of the new waste treatment facility collects all dairy wastewater outflow. Wastewater is then pumped to solids separators, and flows by gravity to anaerobic ponds and aerobic ponds. The upper subsystem is expected to treat the water sufficiently so that the wetland cells may achieve further pollutant reductions. The lower subsystem, comprised of 8 surface wetland cells with an approximate surface area of 5,000 m2, receives outflow from the ponds. The cells are planted with cattail (Typha domingensis), soft-stem bulrush (Scirpus validus), and reed (Phragmites australis). After treatment is completed via the lagoons and ponds followed by the wetland cells, the wastewater can be reused to flush barns or to irrigate crops. Performance of the overall system is evaluated by measuring physical, chemical and biological parameters in water samples taken from selected locations along the treatment system. Chemical parameters studied include biochemical oxygen demand, pH, total suspended solids, nitrogen species. Biological monitoring included coliforms (total and fecal) and Listeria monocytogenes.

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