Combined Electrochemical & Biological Treatment of Industrial Wastewater Using Porous Electrodes and a Packed Bed Aerator

10.32920/ryerson.14648334 ◽

2021 ◽

Author(s):

Robert Mitzakov

Keyword(s):

Laminar Flow ◽

Electrochemical Cell ◽

Flow Region ◽

Packed Bed ◽

Electrochemical Treatment ◽

Porous Electrodes ◽

Turbulent Region ◽

Porous Aluminum ◽

Liquid Flux ◽

Laminar And Turbulent Flow

Zinc, nickel and propylene glycol methyl ether were simultaneously removed from simulated wastewater in a column containing a counter-current packed bed and an electrochemical cell. Rectangular porous aluminum foam cathode and porous stainless steel anode were used in a plate-in-tank configuration. During combined biological and electrochemical treatment the wastewater flux was 0.00183 and 0.00915 m³.m̈².s̈¹ at a constant volumetric air flux of 0.0518 m³.m̈².s̈¹. Over a 72 hour treatment period the BOD5 was reduced by 32% and 55% for each volumetric liquid flux, respectively; zinc was reduced by 98% for both fluxes, and nickel was reduced by 95% and 82%, respectively. For sole electrochemical treatment of 48 hours, laminar and turbulent flow conditions were studied. Operating in the laminar flow region of 0.00183 and 0.00915 m³.m̈².s̈¹; zinc was reduced by 95% for both fluxes; nickel was reduced by 80% and 60%, respectively. For the turbulent region in the electrochemical cell, the volumetric liquid fluxes were 0.0137, 0.0229, 0.0321 and 0.0366 m³.m̈².s̈¹. Per cent reduction of both zinc and nickel in this region was less than that encountered in laminar flow. For all the fluxes in the turbulent region zinc was reduced by 82%; nickel was reduced by 55% at a flux of 0.0137 m³.m̈².s̈¹ and 60% at a flux of 0.0366 m³.m̈².s̈¹. Increasing electrode surface area as a means of improving heavy metal reduction by using rectangular porous material in a plate-in-tank configuration is not a viable option at higher volumetric liquid fluxes.

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Electrochemical removal of zinc and nickel ions from wastewater using porous electrodes

10.32920/ryerson.14653710.v1 ◽

2021 ◽

Author(s):

Qazi Sabir

Keyword(s):

Applied Voltage ◽

Electrochemical Cell ◽

Operating Conditions ◽

Porous Electrodes ◽

Nickel Ions ◽

Porous Aluminum ◽

Liquid Flux ◽

Flow Through ◽

Simulated Wastewater ◽

Aluminum Plates

Simulated wastewater containing Ni++ and Zn++ was treated using an electrochemical cell. Porous aluminum cathode and porous stainless steel anode were used in a flow-through configuration. For porous catholdes, both aluminium foam and corrugated aluminum plates having perforations were used. To study the effects of applied voltage and volumetric liquid flux on the removal of Ni++ and Zn++, the electrochemical cell was operated for 48 hours at different applied voltages of 5, 10, 15, 20 and 25 V, and at different volumetric liquid fluxes both in the laminar (0.00471 and 0.00943 m³.m-².s-¹) and turbulent regimes (0.01414, 0.01886 and 0.02357 m³.m-².s-¹). For the maximum removal of both nickel and zinc ions, the optimum applied voltage and volumetric liquid flux were found to be 12 V and 0.02357 m³.m-².s-¹, respectively; under these operating conditions, the concentrations of Ni++ and Zn++ in the simulated wastewater were reduced by 85.5% and 98%, respectively. Operating beyond an applied voltage of 12 V, the removal of Zn++ was slightly improved and achieved a maximum value of 99.05% at 25 V; however, an opposite trend was observed in case of Ni++ removal, which finally decreased to 56% at 25 V., because of the excessive precipitation of Ni++ as nickel hydoroxide.

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Electrochemical removal of zinc and nickel ions from wastewater using porous electrodes

10.32920/ryerson.14653710 ◽

2021 ◽

Author(s):

Qazi Sabir

Keyword(s):

Applied Voltage ◽

Electrochemical Cell ◽

Operating Conditions ◽

Porous Electrodes ◽

Nickel Ions ◽

Porous Aluminum ◽

Liquid Flux ◽

Flow Through ◽

Simulated Wastewater ◽

Aluminum Plates

Simulated wastewater containing Ni++ and Zn++ was treated using an electrochemical cell. Porous aluminum cathode and porous stainless steel anode were used in a flow-through configuration. For porous catholdes, both aluminium foam and corrugated aluminum plates having perforations were used. To study the effects of applied voltage and volumetric liquid flux on the removal of Ni++ and Zn++, the electrochemical cell was operated for 48 hours at different applied voltages of 5, 10, 15, 20 and 25 V, and at different volumetric liquid fluxes both in the laminar (0.00471 and 0.00943 m³.m-².s-¹) and turbulent regimes (0.01414, 0.01886 and 0.02357 m³.m-².s-¹). For the maximum removal of both nickel and zinc ions, the optimum applied voltage and volumetric liquid flux were found to be 12 V and 0.02357 m³.m-².s-¹, respectively; under these operating conditions, the concentrations of Ni++ and Zn++ in the simulated wastewater were reduced by 85.5% and 98%, respectively. Operating beyond an applied voltage of 12 V, the removal of Zn++ was slightly improved and achieved a maximum value of 99.05% at 25 V; however, an opposite trend was observed in case of Ni++ removal, which finally decreased to 56% at 25 V., because of the excessive precipitation of Ni++ as nickel hydoroxide.

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Predicting the Pressure Drop of Corrugated Sheet Structured Packings in Deep Vacuum Applications

Chemical and Biochemical Engineering Quarterly ◽

10.15255/cabeq.2018.1574 ◽

2019 ◽

Vol 33 (3) ◽

pp. 303-323

Author(s):

Žarko Olujić

Keyword(s):

Pressure Drop ◽

Laminar Flow ◽

Flow Region ◽

Packed Bed ◽

Internal Diameter ◽

Flow Conditions ◽

Natural Choice ◽

Total Reflux ◽

Wire Gauze ◽

Structured Packings

Advanced corrugated sheet structured packings are considered a natural choice for<br /> deep vacuum distillation. In many of these applications that occur at absolute pressures<br /> below 0.01 bar at the top of the column, the low density gas/vapor driven by pressure<br /> ascends through an irrigated packed bed under laminar flow conditions. This implies that the packing geometry features aiming to reduce the form drag of advanced packing may not be as effective, if at all, as experienced in common applications where turbulent flow prevails. To consider this appropriately, a theoretically founded expression for laminar flow friction factor has been incorporated into Delft model (DM). With this extension, the predicted pressure drop within laminar flow region approaches closely that estimated using well-established empirical model available in software package SULCOL. In absence of adequate experimental evidence, extended DM was validated using newest data obtained at FRI with an advanced wire gauze structured packing in total reflux experiments carried out with paraxylene/orthoxylene system at 0.02 and 0.1 bar top pressure in a column with internal diameter of 1.22 m.

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Microfluidic electrochemical cell for in situ structural characterization of amorphous thin-film catalysts using high-energy X-ray scattering

Journal of Synchrotron Radiation ◽

10.1107/s1600577519007240 ◽

2019 ◽

Vol 26 (5) ◽

pp. 1600-1611 ◽

Cited By ~ 3

Author(s):

Gihan Kwon ◽

Yeong-Ho Cho ◽

Ki-Bum Kim ◽

Jonathan D. Emery ◽

In Soo Kim ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Electrochemical Cell ◽

Porous Electrode ◽

High Energy ◽

Porous Electrodes ◽

X Ray ◽

Pdf Analysis ◽

Thin Film Catalysts

Porous, high-surface-area electrode architectures are described that allow structural characterization of interfacial amorphous thin films with high spatial resolution under device-relevant functional electrochemical conditions using high-energy X-ray (>50 keV) scattering and pair distribution function (PDF) analysis. Porous electrodes were fabricated from glass-capillary array membranes coated with conformal transparent conductive oxide layers, consisting of either a 40 nm–50 nm crystalline indium tin oxide or a 100 nm–150 nm-thick amorphous indium zinc oxide deposited by atomic layer deposition. These porous electrodes solve the problem of insufficient interaction volumes for catalyst thin films in two-dimensional working electrode designs and provide sufficiently low scattering backgrounds to enable high-resolution signal collection from interfacial thin-film catalysts. For example, PDF measurements were readily obtained with 0.2 Å spatial resolution for amorphous cobalt oxide films with thicknesses down to 60 nm when deposited on a porous electrode with 40 µm-diameter pores. This level of resolution resolves the cobaltate domain size and structure, the presence of defect sites assigned to the domain edges, and the changes in fine structure upon redox state change that are relevant to quantitative structure–function modeling. The results suggest the opportunity to leverage the porous, electrode architectures for PDF analysis of nanometre-scale surface-supported molecular catalysts. In addition, a compact 3D-printed electrochemical cell in a three-electrode configuration is described which is designed to allow for simultaneous X-ray transmission and electrolyte flow through the porous working electrode.

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Drag Reduction of Polymer Solutions in a Pipe With a Highly Water-Repellent Wall

10.1115/imece1999-1160 ◽

1999 ◽

Author(s):

Keizo Watanabe ◽

Hiroshi Udagawa

Keyword(s):

Pressure Drop ◽

Laminar Flow ◽

Drag Reduction ◽

Polymer Solutions ◽

Tap Water ◽

Acrylic Resin ◽

Water Repellent ◽

Number Range ◽

Surfactant Solutions ◽

Laminar And Turbulent Flow

Abstract By applying a highly water-repellent wall pipe in the drag reduction of polymer solutions, a flow system in which drag reduction is obtained in both laminar and turbulent flow ranges has been realized. Experiments were carried out to measure the pressure drop in pipes with a highly water-repellent wall and an acrylic resin wall by means of a pressure transducer. The diameter of the pipe was 6mm. The polymer solutions tested were PE015 aqueous solutions in the concentration range of 30ppm∼1000ppm. The drag reduction ratio for laminar flow was about 11∼15%. To understand this effect, the pressure drop was measured by using surfactant solutions and degassed water, and by pressurizing tap water in the pipeline. It was shown that the laminar drag reduction does not occur in the case of surfactant solutions although degassed water and pressurizing tap water in the pipeline have no effect on the reduction. In the laminar flow range, the friction factor of a power-law fluid with fluid slip was analyzed by applying the modified boundary condition on fluid slip at the pipe wall, and the analytical results agree with the experimental results in the low Reynolds number range.

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Laminar Mixing in Stirred Tank Agitated by an Impeller Inclined

International Journal of Chemical Engineering ◽

10.1155/2012/858329 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10 ◽

Cited By ~ 9

Author(s):

Koji Takahashi ◽

Yoshiharu Sugo ◽

Yasuyuki Takahata ◽

Hitoshi Sekine ◽

Masayuki Nakamura

Keyword(s):

Numerical Simulation ◽

Laminar Flow ◽

Mixing Time ◽

Flow Region ◽

Experimental Results ◽

Stirred Tank ◽

Simulation Methods ◽

Mixing Performance ◽

Laminar Mixing ◽

Numerical Simulation Methods

The mixing performance in a vessel agitated by an impeller that inclined itself, which is considered one of the typical ways to promote mixing performance by the spatial chaotic mixing, has been investigated experimentally and numerically. The mixing time was measured by the decolorization method and it was found that the inclined impeller could reduce mixing time compared to that obtained by the vertically located impeller in laminar flow region. The effect of eccentric position of inclined impeller on mixing time was also studied and a significant reduction of mixing time was observed. To confirm the experimental results, the velocity profiles were calculated numerically and two novel numerical simulation methods were proposed.

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CFD Study of Pitch Variations On Helically Coiled Pipe in Laminar Flow Region

Journal of Heat Transfer ◽

10.1115/1.4047646 ◽

2020 ◽

Author(s):

Anwer Faraj ◽

Itimad D J Azzawi ◽

Samir Ghazi Yahya ◽

Amer Al-damook

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Laminar Flow ◽

Friction Factor ◽

Flow Structure ◽

Flow Region ◽

Alternative Solution ◽

Experimental Investigations ◽

Coil Diameter ◽

Computational Fluid Dynamics Cfd

Abstract Experimental investigations of the flows inside helically coiled pipe are difficult and may also be expensive, particularly for small diameters. Computational fluid dynamics (CFD) packages, which can easily construct the geometry and change the dimensions with 100% of accuracy, provide an alternative solution for the experimental difficulties and uncertainties. Therefore, a computational fluid dynamics (CFD) study was conducted to analyse the flow structure and the effect of varying the coil pitch on the coil friction factor, through utilising different models' configurations. Two coils were tested, all of them sharing the same pipe and coil diameter: 0.005m and 0.04m respectively. Pitch variations began with 0.01 and 0.05 m for the first, second model respectively. In this study, the velocity was analysed, and the effects of this reduction on coil friction factor were also examined using laminar flow. The results were validated by Ito's equation for the laminar flow.

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