Carbon adsorption systems

Engineering Considerations To effect the good engineering design of an activated carbon adsorption system, it is first necessary to obtain information on the following the actual cubic feet per minute (ACFM) of air to be processed by the adsorber, the temperature of gas stream, the material(s) to be absorbed, the concentration of the material to be adsorbed, and if the intended application is air pollution control such as odor control - then the odor threshold of the material to be adsorbed. In addition, data is needed on the presence of other constituents in the gas stream, and whether or not solvent recovery is economical. 

Applications of carbon adsorption go far beyond conventional water treatment applications which we will discuss in a general sense shortly. Table 8 provides a summary of the key applications of carbon adsorption systems for liquid phase applications. 

For effective volatilization using an enclosed mechanical aeration system, contaminated soil is mixed in a pug mill or rotary drum. The gasoline components are released from the soil matrix by the churning action of the air/soil contact. The induced airflow within the chamber captures the gasoline emissions and passes them through an air pollution control device (e.g., a water scrubber or vapor-phase carbon adsorption system) before they are discharged through a properly sized stack. 

Carbonaceous resins, in hazardous waste management, 25 813 Carbon adsorbents, preparation, 1 586 Carbon adsorption, in hazardous waste management, 25 811-813 Carbon adsorption system, 26 681 Carbon adsorption units, 25 812 Carbon aerogels applications, 1 767 preparation, 1 752... 

It adequately treats the low volumes of offgases produced in the process, including those from the SCWO reactors, through catalytic oxidation and activated carbon adsorption systems. 

Operating and Capital Costs of South Lake Tahoe Carbon Adsorption System (1969-1970) ... 

A printing eompany must reduce and recover the amount of toluene it emits from its Rotograve printing operation. The eompany submits some preliminary information on installing a carbon adsorption system. You, the primary consultant, are given the following information ... 

Kilduff, J.E., Karanfil, T., and Weber, W.J., Jr (1996). Competitive interactions among components of humic acids in granular activated carbon adsorption systems effects of solution chemistry. Environ. Sci. Technol., 30, 1344—51. 

In wastewater treatment, carbon adsorption systems often use granular activated carbon. The design of the activated carbon system consists essentially in determining ... 

Conventionally, PAG, GAC, or extruded activated carbon serves as adsorbents for contaminants from treated waters directly (Fig. 11, solid lines) or indirectly (dotted lines in the Fig. 11). In the latter option, volatiles from water are first transferred to the gas phase by air stripping [45]. The contaminated air is subsequently passed throu the carbon bed, which enables the effective removal of the stripped compounds. The removal of contaminants Irom waters with the use of carbon adsorption systems is particularly effective for final purification of water discharges from other remedial technologies. 

Scrubbers (water and aqueous base) for the processing areas Carbon adsorption systems for specific emission points Trim condensers as required in processing vents Thermal oxidizer and stack for process vent emissions Tanks (segregated by waste category, dikes as required)... 

Adsorption is an exothermic process. The adsorption enthalpy, decreases as the load of adsorbed molecules increases. In activated carbon adsorption systems for solvent recovery, the liberated adsorption enthalpy normally amounts to 1.5 times the evaporation enthalpy at the standard working capacities which can result in a 20 K or more temperature increase. In the process, exothermic adsorption mechanisms may coincide with endothermic desorption mechanisms. ... 

Remediation. Many companies specialize in hazardous-waste remediation by providing a variety of disposal services and equipment, not limited to catalytic oxidizers and carbon adsorption systems. Remediation includes reduction and cleanup of hazardous wastewater by using oil-water separators to separate oil and solids from wastewater effluents of petroleum-based industries. Other hazardous-vwiste remediation services include demolition and removal of hazardous materials such as asbestos, removal of leaky fuel tanks, cleanup of contaminated sods, and the construction of slurry walls to aid in the remediation of groundwater that is polluted with hazardous waste. Bioremediation is also a growing field that involves disposal of medical and laboratory wastes often by using microorganisms to break down the hazardous materials. 

Michaslis T.B. "Techniques to Detect Failure in Carbon Adsorption Systems," EPA Report340/1—80011, April 1980. USP 8,016,914 claims use of temperature to manage operation of twin adsorption beds — used for recovery of hydrogen from mixed gas systems. The claims include only operation of pressure swing systems for adsorption of hydrogen, and not recovery of solvents from activated carbon. 

The final step is the tertiary treatment. It is used for specific contaminants which cannot be removed by the secondary treatment. This phase is not always present in a WWT, it depends on the origin of the sewage and the final use of the water output. Individual treatment processes sometimes are necessary to remove nitrogen, phosphorus, additional suspended solids, refractory organics, heavy metals and dissolved solids. The technologies to be used depend on the contaminants which must be removed, i.e. filters and separation membranes, systems for dechlorination and disinfection, reverse osmosis systems, ion exchangers, activated carbon adsorption systems and physical-chemical treatments. 

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