scholarly journals Powdered activated carbon (PAC) – vacuum-assisted air gap membrane distillation (V-AGMD) hybrid system to treat wastewater containing surfactants: Effect of operating conditions

2020 ◽  
Vol 26 (5) ◽  
pp. 200377-0
Author(s):  
Yusik Kim ◽  
Yongjun Choi ◽  
Jihyeok Choi ◽  
Sangho Lee
Keyword(s):  
Activated Carbon ◽  
Pure Water ◽  
Membrane Distillation ◽  
Air Gap ◽  
Powdered Activated Carbon ◽  
Operating Conditions ◽  
Synthetic Wastewater ◽  
Air Gap Membrane Distillation ◽  
Short Period ◽  
Membrane Wetting

Membrane distillation (MD), which uses hydrophobic porous membranes with a temperature gradient to produce pure water, has the potential to treat high-salinity wastewater. However, it cannot directly treat wastewater containing surfactants, which lower the surface tension and thus result in membrane wetting. To overcome this limitation, this study proposed a hybrid process consisting of powdered activated carbon (PAC) adsorption and MD, where PAC removes the surfactants in the wastewater to alleviate the wetting of the MD membranes. A bench-scale vacuum-assisted air gap MD (V-AGMD) equipment was adopted for the treatment of synthetic wastewater containing inorganic salts and surfactants. The conductivity of the permeate from V-AGMD was continuously monitored to detect membrane wetting. Without the use of PAC, the MD membrane was wetted within a short period, which decreased as the surfactant concentration increased. On the other hand, the addition of PAC retards the onset of wetting even at higher surfactant concentrations. The effectiveness of the PAC addition to the MD system on wetting control was examined under various conditions to elucidate its mechanism.

Experimental Study and Numerical Simulation of the Air Gap Membrane Distillation (AGMD) Process

2016 ◽  
Vol 11 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Ehsan Karbasi ◽  
Javad Karimi-Sabet ◽  
J. Mohammadi Roshandeh ◽  
M. A. Moosavian ◽  
H. Ahadi
Keyword(s):  
Numerical Simulation ◽  
Membrane Surface ◽  
Membrane Distillation ◽  
Air Gap ◽  
Operating Conditions ◽  
Permeate Flux ◽  
Air Gap Membrane Distillation ◽  
Temperature Polarization ◽  
Output Ratio ◽  
Cfd Method

Abstract Some challenges, including inappropriate distribution of currents on the membrane surface, poor hydrodynamics and existing severe temperature polarization (TP) phenomenon in MD modules, impede industrialization of MD process. Computational fluid dynamics (CFD) method was used for numerical simulation of hydrodynamics in air gap membrane distillation modules. One of two simulated modules in this work is a novel developed one in which heat and mass transfer data was compared with available literature data. Moreover, the effect of using baffles in module was investigated. Comparison between the novel module and conventional module indicates higher trans-membrane mass flux and gained output ratio (GOR) coefficient by 7% and 15%, respectively. Moreover, the effects of different operating conditions including feed temperatures and feed flow rates on permeate flux were investigated.

scholarly journals Enhancement of the air gap membrane distillation system performance by using the water gap module

2020 ◽  
Vol 20 (7) ◽  
pp. 2884-2902
Author(s):  
Mostafa Abd El-Rady Abu-Zeid ◽  
Xiaolong Lu ◽  
Shaozhe Zhang
Keyword(s):  
Membrane Distillation ◽  
Air Gap ◽  
Operating Conditions ◽  
Coolant Temperature ◽  
Concentration Boundary ◽  
Air Gap Membrane Distillation ◽  
Distillation System ◽  
Negative Effect ◽  
In Series ◽  
Output Ratio

Abstract The negative effect of an air gap layer presented between the membrane and cooling plate on air gap membrane distillation (AGMD) performance was diminished largely by inserting a water gap membrane distillation (WGMD) module in series. The new design of air-gap–water-gap membrane distillation (AG-WG)MD was evaluated experimentally by comparing with an AGMD system under different operating conditions. In theory, mass and heat transfer in the new (AG-WG)MD and imitative AGMD systems were analyzed. Experimental outcomes showed that a new (AG-WG)MD design profoundly enhanced flux (Pd) and gained output ratio (GOR), and greatly decreased energy consumption (STEC) and heat input (EH.I). At a concentration of 5,000 mg/L, coolant temperature of 20 °C, and flow rate of 18 L/h, Pd was promoted by 76.26%, 40.84%, 35.45%, 30.91%, and GOR by 46.38%, 33.46%, 31.27%, 26.65%, in addition to STEC being reduced about 55.63%, 46.81%, 43.66%, 38.30%, and EH.I around 31.31%, 25.84%, 23.53%, 20.55%, from the AGMD to (AG-WG)MD system at feed temperatures of 50 °C, 60 °C, 70 °C, and 80 °C, respectively. The outcomes proved that the AGMD performance could be significantly promoted by integrating with WGMD in a combined MD system. This combination increased the temperature difference across the membrane and decreased thermal-concentration boundary layers for the AGMD system.

scholarly journals Experimental analysis of a novel helical air gap membrane distillation system

2021 ◽  
Author(s):  
Vandita T. Shahu ◽  
S. B. Thombre
Keyword(s):  
Flow Rate ◽  
Experimental Analysis ◽  
Membrane Distillation ◽  
Air Gap ◽  
Operating Conditions ◽  
Coolant Temperature ◽  
Feed Water ◽  
Air Gap Membrane Distillation ◽  
Feasible Solutions ◽  
Water Problems

Abstract Membrane distillation presents one of the feasible solutions to fresh water problems. The present study aims to develop an innovative Helical Air Gap Membrane Distillation (HAGMD) system and to analyze its behavior under different operating conditions. In this design the condenser is made up of a cylindrical copper tube with continuous helical fins over it, that increases the total available condensation area by almost 45% and enhances the overall heat transfer throughout the module. The presence of fins in the gap also reduces the total air gap width by almost 64%and therefore improves the flux production. A detailed experimental analysis is carried out for a better understanding of the underlying phenomenon. The effect of feed water temperature, feed flow rate, cold flow rate, coolant temperature and feed salinity on the performance of HAGMD is investigated experimentally. The analysis shows that the finned condenser results in very high flux. The maximum flux obtained from the system was 20 kg/m2 hr with feed of 5gm/liter salinity and a diving force temperature difference of 45 °C.

scholarly journals Removal of organic pollutants from produced water by batch adsorption treatment

2021 ◽  
Author(s):  
Eman Hashim Khader ◽  
Thamer Jassim Mohammed ◽  
Nourollah Mirghaffari ◽  
Ali Dawood Salman ◽  
Tatjána Juzsakova ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Produced Water ◽  
Oxygen Demand ◽  
Powdered Activated Carbon ◽  
Pollutant Removal ◽  
Operating Conditions ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Zeolite X

AbstractThis paper studied the adsorption of chemical oxygen demand (COD), oil and turbidity of the produced water (PW) which accompanies the production and reconnaissance of oil after treating utilizing powdered activated carbon (PAC), clinoptilolite natural zeolite (CNZ) and synthetic zeolite type X (XSZ). Moreover, the paper deals with the comparison of pollutant removal over different adsorbents. Adsorption was executed in a batch adsorption system. The effects of adsorbent dosage, time, pH, oil concentration and temperature were studied in order to find the best operating conditions. The adsorption isotherm models of Langmuir, Freundlich and Temkin were investigated. Using pseudo-first-order and pseudo-second-order kinetic models, the kinetics of oil sorption and the shift in COD content on PAC and CNZ were investigated. At a PAC adsorbent dose of 0.25 g/100 mL, maximum oil removal efficiencies (99.57, 95.87 and 99.84 percent), COD and total petroleum hydrocarbon (TPH) were identified. Moreover, when zeolite X was used at a concentration of 0.25 g/100 mL, the highest turbidity removal efficiency (99.97%) was achieved. It is not dissimilar to what you would get with PAC (99.65 percent). In comparison with zeolites, the findings showed that adsorption over PAC is the most powerful method for removing organic contaminants from PW. In addition, recycling of the consumed adsorbents was carried out in this study to see whether the adsorbents could be reused. Chemical and thermal treatment will effectively regenerate and reuse powdered activated carbon and zeolites that have been eaten. Graphic abstract

scholarly journals Treatment of RO brine from CSG produced water by spiral-wound air gap membrane distillation — A pilot study

Desalination ◽  
2015 ◽  
Vol 366 ◽  
pp. 121-129 ◽  
Author(s):  
Hung C. Duong ◽  
Allan R. Chivas ◽  
Bart Nelemans ◽  
Mikel Duke ◽  
Stephen Gray ◽  
...  
Keyword(s):  
Pilot Study ◽  
Produced Water ◽  
Membrane Distillation ◽  
Air Gap ◽  
Air Gap Membrane Distillation ◽  
Spiral Wound

scholarly journals Design study of the coupling of an air gap membrane distillation unit to an air conditioner

Desalination ◽  
2017 ◽  
Vol 420 ◽  
pp. 308-317 ◽  
Author(s):  
Ahmadou Tidiane Diaby ◽  
Paul Byrne ◽  
Patrick Loulergue ◽  
Béatrice Balannec ◽  
Anthony Szymczyk ◽  
...  
Keyword(s):  
Membrane Distillation ◽  
Air Gap ◽  
Distillation Unit ◽  
Air Conditioner ◽  
Design Study ◽  
Air Gap Membrane Distillation

scholarly journals Air-gap membrane distillation as a one-step process for textile wastewater treatment

2019 ◽  
Vol 360 ◽  
pp. 1330-1340 ◽  
Author(s):  
Sebastian Leaper ◽  
Ahmed Abdel-Karim ◽  
Tarek A. Gad-Allah ◽  
Patricia Gorgojo
Keyword(s):  
Wastewater Treatment ◽  
Textile Wastewater ◽  
Membrane Distillation ◽  
Air Gap ◽  
Step Process ◽  
Air Gap Membrane Distillation ◽  
One Step ◽  
Textile Wastewater Treatment

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

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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