Evidence of powdered activated carbon preferential collection and enrichment on electrostatic precipitator discharge electrodes during sorbent injection for mercury emissions control

2012 ◽  
Vol 93 (1) ◽  
pp. 8-12 ◽  
Author(s):  
Vinit Prabhu ◽  
Taehoon Kim ◽  
Yasmin Khakpour ◽  
Shannon D. Serre ◽  
Herek L. Clack
Keyword(s):  
Activated Carbon ◽  
Electrostatic Precipitator ◽  
Powdered Activated Carbon ◽  
Emissions Control ◽  
Mercury Emissions ◽  
Sorbent Injection

Unsteady Modeling of Powdered Activated Carbon Deposition on Collection Electrode of a Lab-Scale Electrostatic Precipitator (ESP)

2012 ◽  
Author(s):  
Yasmin Khakpour ◽  
Herek L. Clack
Keyword(s):  
Activated Carbon ◽  
Particle Deposition ◽  
Electrostatic Precipitator ◽  
Activated Carbons ◽  
Collection Efficiency ◽  
Continuous Phase ◽  
Powdered Activated Carbon ◽  
Computational Domain ◽  
Discrete Phase Model ◽  
Discrete Phase

Particulate sampling in the flue gas at the Electrostatic Precipitator (ESP) outlet during injection of powdered activated carbons (PACs) has provided strong anecdotal evidence indicating that injected PACs can penetrate the ESP in significant concentrations. The low resistivity of PAC is consistent with poor collection efficiency in an ESP and lab-scale testing has revealed significantly different collection behavior of PAC in an ESP as compared to fly ash. The present study illustrates the use of a commercial CFD package — FLUENT — to investigate precipitation of powdered activated carbon (PAC) in the presence and absence of electric field. The computational domain is designed to represent a 2-D wire-plate ESP channel. The governing equations include those covering continuous phase transport, electric potential, air ionization, and particle charging. The particles are tracked using a Lagrangian Discrete Phase Model (DPM). In addition, a custom user-defined function (UDF) uses a deforming boundary condition and a prescribed critical particle velocity to account for particle deposition and dust-cake growth on the electrodes. The effect of Electrohydrodynamics (EHD) induced flow on the ESP collection efficiency under various flow and particle characteristics as well as different ESP configurations are illustrated.

Effect of operational modes on the removal of a synthetic organic chemical by powdered activated carbon during ultrafiltration

2001 ◽  
Vol 1 (5-6) ◽  
pp. 39-47
Author(s):  
Y. Matsui ◽  
A. Yuasa ◽  
F. Colas
Keyword(s):  
Activated Carbon ◽  
Cross Flow ◽  
Powdered Activated Carbon ◽  
Organic Chemical ◽  
Filtration Cycle ◽  
Dead End ◽  
Synthetic Organic Chemical ◽  
The Cross ◽  
Short Time ◽  
Operational Modes

The effects of operational modes on the removal of a synthetic organic chemical (SOC) in natural water by powdered activated carbon (PAC) during ultrafiltration (UF) were studied, through model simulations and experiments. The removal percentage of the trace SOC was independent of its influent concentration for a given PAC dose. The minimum PAC dosage required to achieve a desired effluent concentration could quickly be optimized from the C/C0 plot as a function of the PAC dosage. The cross-flow operation was not advantageous over the dead-end regarding the SOC removal. Added PAC was re-circulated as a suspension in the UF loop for only a short time even under the cross-flow velocity of gt; 1.0 m/s. The cross-flow condition did not contribute much to the suspending of PAC. The pulse PAC addition at the beginning of a filtration cycle resulted in somewhat better SOC removal than the continuous PAC addition. The increased NOM loading on PAC which was dosed in a pulse and stayed longer in the UF loop could possibly further decrease the adsorption rate.

Fate of Toxic Organic Compounds in Activated Sludge and Integrated PAC Systems

1987 ◽  
Vol 19 (3-4) ◽  
pp. 471-482 ◽  
Author(s):  
W. J. Weber ◽  
B. E. Jones ◽  
L. E. Katz
Keyword(s):  
Activated Carbon ◽  
Activated Sludge ◽  
Organic Compounds ◽  
Powdered Activated Carbon ◽  
Carbon Adsorption ◽  
Powdered Carbon ◽  
Benzene Toluene ◽  
Adsorptive Properties ◽  
Carbon Concentrations ◽  
Toxic Organic Compounds

The addition of powdered activated carbon (PAC) to activated sludge treatment systems to enhance removal of specific toxic organic compounds from wastewater was evaluated. Nine organic compounds encompassing a range of solubility, volatility, biodegradability, and adsorptive properties were studied. Kate and equilibrium investigations were conducted to quantify the removal mechanisms of volatilization, biodegradation, biosorption, and carbon adsorption. Results from steady-state bioreactor studies showed that the addition of less than 100 mg/ℓ powdered activated carbon to the influent did not enhance the removal of the biodegradable target compounds investigated: benzene, toluene, ethylbenzene, o-xylene, chlorobenzene, and nitrobenzene. Significantly improved removals of the poorly degradable and non-biodegradable compounds 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, and lindane occurred at influent powdered carbon concentrations in the 12.5 to 25 mg/ℓ range. Influent powdered carbon concentrations of 100 mg/ℓ effected overall removals of greater than 90%. The addition of powdered activated carbon not only reduced effluent concentrations but also reduced the amounts of the volatile compounds stripped to the atmosphere.

scholarly journals Hazardous cyanobacteria integrity response to velocity gradient and powdered activated carbon in water treatment plants

2021 ◽  
Vol 773 ◽  
pp. 145110
Author(s):  
Samylla Oliveira ◽  
Allan Clemente ◽  
Indira Menezes ◽  
Amanda Gois ◽  
Ismael Carloto ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Velocity Gradient ◽  
Powdered Activated Carbon ◽  
Water Treatment Plants
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