Design powdered activated carbon

A powdered activated carbon fed activated sludge process is designed to treat 15,000 GPD of pharmaceutical wastewater. The SCOD (soluble chemical oxygen demand) of the treated effluent is 590 mg/L. Determine the dose of PAC (powdered activated carbon) required for further reduction of effluent SCOD from 590 mg/L to 200 mg/L. Use the Freundlich equation [48] XjM = (3.7 x 10 ) to determine the dose of powdered activated carbon. 

Powdered activated carbon (PAC) PAC is made up of crashed or ground carbon particles, 95-100% of which will pass through a designated sieve—0.297 mm according to the American Water Works Association Standard, or 0.177 mm according to ASTM D5158. PAC is mainly used for biological treatment. 

Finely powdered activated carbon is incorporated in fabrics for garments designed to protect the wearer against injuries from vesicant and other poisonous vapors. Kingan, Phillips, and Wilsdon28... 

Most kboratoiy tests are designed for evaluating powdered, activated carbons, with the adsorption isotherms, giving a rough first estimate of how well a carbon will perform in a given application. Data collected during an adsorption test will describe the performance of the carbon and will yield valuable information if properly mterpreted. 

Activated carbons in commercial use are mainly in two forms powder form and granular or pelletized form. Powdered activated carbons (PAC) in most cases are produced from wood in the form of saw dust. The average size of PAC is in the range of 15 to 25 pm and the geometrical standard deviation is between 0.15 to 0.266. This particle size assures that intraparticle diffusion will not be the rate limiting step thus the adsorption operation is designed from the view point of selection of... 

The clean-np systems are based on various technologies, the oldest of which being activated carbon adsorption. This process usually comprises the passing of solventladen air throngh specially designed adsorber vessels, containing packed beds of grannlar or powdered activated carbon. A minimum of two adsorbers are used if... 

Each application for carbon treatment must be cognizant of the characteristics of the contaminant to be removed and designed with the proper carbon type in order to attain optimum results. Basically, there are two forms of activated carbon powdered and granular. The former are particles that are less than U.S. Sieve Series No. 50, while the latter are larger. The adsorption rate is influenced by carbon particle size, but not the adsorptive capacity which is related to the total surface area. —... 

Catalytic tests in sc CO2 were run continuously in an oil heated flow reactor (200°C, 20 MPa) with supported precious metal fixed bed catalysts on activated carbon and polysiloxane (DELOXAN ). We also investigated immobilized metal complex fixed bed catalysts supported on DELOXAN . DELOXAN is used because of its unique chemical and physical properties (e. g. high pore volume and specific surface area in combination with a meso- and macro-pore-size distribution, which is especially attractive for catalytic reactions). The effects of reaction conditions (temperature, pressure, H2 flow, CO2 flow, LHSV) and catalyst design on reaction rates and selectivites were determined. Comparative studies were performed either continuously with precious metal fixed bed catalysts in a trickle bed reactor, or discontinuously in stirred tank reactors with powdered nickel on kieselguhr or precious metal on activated carbon catalysts. Reaction products were analyzed off-line with capillary gas chromatography. 

One of the other studies on the influence of suspended solid materials on the mass transfer coefficient is that of Alper et al. (5).They employed various stirred cells of different designs,however,in all of the experiments gas-liquid interfacial area remained reasonably flat and could be taken as equal to the geometrical area.The values of k. was low so that the liquid film thickness was bigger than 50 pm.In agreement with above studies, their data showed that no effect of particles on k, values when inert particles,such as finely powdered quartz sand and oxirane acrylic beads,were employed.However,a completely different picture was obtained with highly porous particles of strong adsorbing property,such as activated carbon,which increased k considerably(5),... 

Batteries of this type have been developed with film, tablet, and cylindrical designs. In the first type, the electrolyte film is applied onto the metal anode or cathodic current collector by sputtering or vaporization. The tablet and cylindrical batteries designed for comparatively high drain rates employ porous electrodes manufactured by pressing a mixture of the powders of the active materials (silver or polyiodide), electrolyte, and conductive additive (carbon black, etc.). 

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