scholarly journals Study of Chromium Removal by the Electrodialysis of Tannery and Metal-Finishing Effluents

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Ruan C. A. Moura ◽  
Daniel A. Bertuol ◽  
Carlos A. Ferreira ◽  
Franco D. R. Amado
Keyword(s):  
Wastewater Treatment ◽  
Ion Exchange ◽  
Electric Field ◽  
Driving Force ◽  
Membrane Separation ◽  
Physicochemical Process ◽  
Separation Technique ◽  
Chromium Removal ◽  
Metal Finishing ◽  
Interesting Alternative

The metal-finishing and tannery industries have been under strong pressure to replace their current wastewater treatment based on a physicochemical process. The electrodialysis process is becoming an interesting alternative for wastewater treatment. Electrodialysis is a membrane separation technique, in which ions are transported from one solution to another through ion-exchange membranes, using an electric field as the driving force. Blends of polystyrene and polyaniline were obtained in order to produce membranes for electrodialysis. The produced membranes were applied in the recovery of baths from the metal-finishing and tannery industries. The parameter for electrodialysis evaluation was the percentage of chromium extraction. The results obtained using these membranes were compared to those obtained with the commercial membrane Nafion 450.

Water Pollutants and Their Removal Techniques

2019 ◽  
pp. 114-133
Author(s):  
P. Senthil Kumar ◽  
A. Saravanan
Keyword(s):  
Wastewater Treatment ◽  
Ion Exchange ◽  
Membrane Separation ◽  
Low Cost ◽  
Chemical Precipitation ◽  
Human Wellbeing ◽  
Individual Care ◽  
Water And Wastewater ◽  
Biological Methods ◽  
Electrochemical Ion Exchange

A developing number of contaminants are entering into water supplies from industrialization and human actions. On account of pharmaceuticals, individual care items, hormones, pesticides, and other substance intensifies that are discharged into the water supply, rising contaminations distinguished in water may have contrary effects to human wellbeing and aquatic environments. In perspective of the previously mentioned issues, late consideration has been centered on the improvement of more effective, low cost, vigorous strategies for wastewater treatment, without additionally focusing on nature or endangering human wellbeing by the treatment itself. The treatment methodologies include primary, secondary, and tertiary treatment using chemical and biological processes. Various strategies, for example, electrochemical, ion exchange, chemical precipitation, coagulation, membrane separation, adsorption, dialysis, flotation, and biological methods have been utilized for the expulsion of harmful contaminations from water and wastewater.

scholarly journals Effect of Surface Inhomogeneity of Ion-Exchange Membranes on the Mass Transfer Efficiency in Pulsed Electric Field Modes

Membranes ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 40 ◽  
Author(s):  
Dmitrii Butylskii ◽  
Ilya Moroz ◽  
Kseniya Tsygurina ◽  
Semyon Mareev
Keyword(s):  
Mass Transfer ◽  
Ion Exchange ◽  
Electric Field ◽  
Membrane Separation ◽  
Rapid Development ◽  
Concentration Field ◽  
Pulsed Electric Field ◽  
Limiting Current ◽  
Ion Exchange Membranes ◽  
Low Frequencies

Despite the growing interest in pulsed electric field modes in membrane separation processes, there are currently not many works devoted to studying the effect of the surface properties and composition of ion-exchange membranes on their efficiency in these modes. In this paper, we have shown the effect of increasing mass transfer using different kinds of ion-exchange membranes (heterogeneous and homogeneous with smooth, undulated, and rough surfaces) during electrodialysis in the pulsed electric field modes at underlimiting and overlimiting currents. It was found that the maximum increment in the average current is achieved when the average potential corresponds to the right-hand edge of the limiting current plateau of the voltammetric curve, i.e., at the maximum resistance of the system in the DC mode. For the first time, the development of electroconvective vortices was visualized in pulsed electric field modes and it was experimentally shown that even at relatively low frequencies, a non-uniform concentration field is preserved at the time of a pause, which stimulates the rapid development of electroconvection when pulses are switched on again. In the case of relatively high pulse frequencies, the electroconvective vortices formed during a pulse lapse do not completely decay during a pause; they only slightly decrease in size.

Enhanced Treatment Ability of Membrane Technology by Integrating an Electric Field for Dye Wastewater Treatment: A Review

2018 ◽  
Vol 101 (5) ◽  
pp. 1341-1352 ◽  
Author(s):  
Chen Li ◽  
Meihan Zhang ◽  
Chengwen Song ◽  
Ping Tao ◽  
Menghan Sun ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Electric Field ◽  
Membrane Fouling ◽  
Industrial Wastewater ◽  
Membrane Separation ◽  
Dye Wastewater ◽  
Integrated Technology ◽  
Performance Requirements ◽  
Current Trends ◽  
Treatment Technologies

Abstract The increasing environmental awareness and stricter regulations have prompted the developments of various treatment technologies for dye wastewater. Membrane separation receives extensive attention as a promising technology because of many advantages. However, higher removal performance requirements and membrane fouling issues make a single separation method inadequate for the removal of dyes from industrial wastewater. Exerting an electric field on membrane separation system for dye wastewater treatment has already been proposed and newly developed in recent years because each technology complements the advantages and overcomes the challenges of the other. Although the amount of literature in this field is limited, this integrated technology has exhibited good performance on dye removal and is believed to have a bright prospect. This review mapped out the previous studies and current trends as well as provided a prospective outlook for advances in various membrane-combining technologies with an electric field, especially with the electric advanced oxidation processes. The different combination patterns, performance evaluations, removal mechanisms, and treatment parameters are gathered and discussed.

The Staging of Large Wastewater Treatment Plants - A “Modular” Approach

1992 ◽  
Vol 25 (4-5) ◽  
pp. 67-73
Author(s):  
H. Fleckseder ◽  
L. Prendl ◽  
H. Meulenbroek
Keyword(s):  
Wastewater Treatment ◽  
Driving Force ◽  
Wastewater Treatment Plants ◽  
Aeration Tank ◽  
Modular Approach ◽  
Central European ◽  
Plant Hydraulics ◽  
The World ◽  
Whole Life Cycle ◽  
Over Time

The primary driving force for re-investments in wastewater treatment plants in Austria - and also other countries in Central Europe - is at present not an increase in load to treatment but a marked increase in effluent requirements to be fulfilled. (The re-investments necessary for sludge handling and treatment remain outside this paper.) Within a period of 20 years, the load specific requirements on aeration tank volume rose five- to tenfold, when Lv = 2.0 kg BOD5/(m3d) was the starting value, and roughly doubled for final clarifiers. In addition, the importance of the application and expansion of primary sedimentation decreased as well. This development over time in Central European countries as well as the need to utilize previous investments as long as possible - 35 to 60 years for civil works are common as periods of depreciation - indicate that investments in new plant at any location in the world have to consider the possible whole life cycle of a plant and that plant hydraulics becomes the “key hook” for expandability.

Municipal wastewater treatment in Berlin with deep tanks and flotation for secondary clarification

1996 ◽  
Vol 33 (12) ◽  
pp. 199-210
Author(s):  
R. Gnirss ◽  
A. Peter-Fröhlich ◽  
V. Schmidt
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Energy Requirements ◽  
Municipal Wastewater Treatment ◽  
Space Saving ◽  
Process Energy ◽  
Near Future ◽  
Interesting Alternative ◽  
Pilot Tests

For municipal wastewater treatment, space-saving 10m deep activated sludge tanks are an interesting alternative to conventional tanks of shallow construction. Results from pilot tests in the Berlin-Ruhleben WWTP have shown that the biological P-elimination, nutrification and denitrification processes can be implemented as in shallow tanks. However, the activated sludge did not settle satisfactorily. Flotation was implemented in the process for secondary clarification and in the meanwhile has shown to be advantageous. Tests run over a period of some years with the pilot plant have proven the feasibility of this process. Energy requirements for both systems were found to be approximately the same. A cost estimate based on a preplan revealed a 10% advantage in favour of the 10m WWTP with flotation. For these reasons, one 10m WWTP with flotation for secondary clarification and a capacity of 80,000 m3/d will be built in Berlin in the near future.

Floc size distribution and bacterial activities in membrane separation activated sludge processes for small-scale wastewater treatment/reclamation

1997 ◽  
Vol 35 (6) ◽  
pp. 37-44 ◽  
Author(s):  
Boran Zhang ◽  
Kazuo Yamamoto ◽  
Shinichiro Ohgaki ◽  
Naoyuki Kamiko
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Membrane Separation ◽  
Small Scale ◽  
Nitrification Rate ◽  
Floc Size ◽  
Denitrification Activity ◽  
Concentration Changes ◽  
Activated Sludge Processes

Activated sludges taken from full-scale membrane separation processes, building wastewater reuse system (400m3/d), and two nightsoil treatment plants (50m3/d) as well as laboratory scale membrane separation bioreactor (0.062m3/d) were analyzed to characterize membrane separation activated sludge processes (MSAS). They were also compared with conventional activated sludges(CAS) taken from municipal wastewater treatment plants. Specific nitrification activity in MSAS processes averaged at 2.28gNH4-N/kgMLSS.h were higher than that in CAS processes averaged at 0.96gNH4-N/kgMLSS.h. The denitrification activity in both processes were in the range of 0.62-3.2gNO3-N/kgMLSS.h without organic addition and in the range of 4.25-6.4gNO3-N/kgMLSS.h with organic addition. The organic removal activity in nightsoil treatment process averaged at 123gCOD/kgMLSS.h which was significantly higher than others. Floc size distributions were measured by particle sedimentation technique and image analysis technique. Flocs in MSAS processes changed their sizes with MLSS concentration changes and were concentrated at small sizes at low MLSS concentration, mostly less than 60 μm. On the contrary, floc sizes in CAS processes have not much changed with MLSS concentration changes and they were distributed in large range. In addition, the effects of floc size on specific nitrification rate, denitrification rate with and without organic carbon addition were investigated. Specific nitrification rate was decreased as floc size increased. However, little effect of floc size on denitrification activity was observed.

Recent progress and prospects of polymeric hollow fiber membranes for gas application, water vapor and particulate matters removal

2021 ◽  
Author(s):  
Hui Shen Lau ◽  
Wai Fen Yong
Keyword(s):  
Water Vapor ◽  
Hollow Fiber ◽  
Recent Progress ◽  
Membrane Separation ◽  
Environmental Awareness ◽  
Separation Technique ◽  
Air Purification ◽  
Particulate Matters ◽  
Hollow Fiber Membranes ◽  
Clean Air

The increasing challenges in clean air demand have invigorated growing environmental awareness to secure effective air purification and separation technique. Membrane separation has drawn interdisciplinary attention and emerged as an...

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