Volatile organic compounds removing

Zaitan H., Chafik T., FTIR Determination of Adsorption Characteristics for Volatile Organic Compounds Removal on Diatomite Mineral Compared to Commercial Silica (2005) C.R. Chimie 8,1701-1708. 

Wilson, D. J. 1992. Groundwater Cleanup by In-situ Air Sparging. II. Modeling of Dissolved Volatile Organic Compound Removal, Separation Science and Technology, vol. 27, no. 13, pp. 1675-1690. 

Thevenet F., Sivachandiran, L., Guaitella, O., Barakat C., and Rousseau, A. (2014) Plasma-catalyst coupling for volatile organic compound removal and indoor air treatment a review./. Phys. D Appl. Phys., 47 (22), 224011. 

Nelson, T. F., Blacksmith, J. R., and Randall, J. L., 1984, Field Evaluation of Volatile Organic Compound Removal Efficiency for Full-Scale Carbon Adsorption Systems, EPA-600/D-84-211, PB 84-238690, August. 

M., and Ferreira, P. (2008) Synthesis and characterisation of organo-silica hydrophobic clay heterostructures for volatile organic compounds removal. Microporous Mesoporous Mater., Ill,... 

Feng CY, Khulbe KC, Tabe S (2012) Volatile organic compound removal by membrtme gas stripping using electro-spun nanofiber membrane. Desalination 287 98-102... 

The removal of volatile organic compounds (VOC) from air is most often accompHshed by TSA. Air streams needing treatment can be found in most chemical and manufacturing plants, especially those using solvents. At concentrations from 500 to 15,000 ppm, recovery of the VOC from steam used to regenerate activated carbon adsorbent thermally is economically justified. Concentrations above 15,000 ppm ate typically in the explosive range and... 

Liquid nitrogen is used in cold traps to remove and recover solvents or volatile organic compounds from gas streams to reduce atmospheric emissions. Liquid nitrogen can be used to accelerate the cooldown time for process reactors (29). 

Oxidation of cumene to cumene hydroperoxide is usually achieved in three to four oxidizers in series, where the fractional conversion is about the same for each reactor. Fresh cumene and recycled cumene are fed to the first reactor. Air is bubbled in at the bottom of the reactor and leaves at the top of each reactor. The oxidizers are operated at low to moderate pressure. Due to the exothermic nature of the oxidation reaction, heat is generated and must be removed by external cooling. A portion of cumene reacts to form dimethylbenzyl alcohol and acetophenone. Methanol is formed in the acetophenone reaction and is further oxidized to formaldehyde and formic acid. A small amount of water is also formed by the various reactions. The selectivity of the oxidation reaction is a function of oxidation conditions temperature, conversion level, residence time, and oxygen partial pressure. Typical commercial yield of cumene hydroperoxide is about 95 mol % in the oxidizers. The reaction effluent is stripped off unreacted cumene which is then recycled as feedstock. Spent air from the oxidizers is treated to recover 99.99% of the cumene and other volatile organic compounds. 

Potable Water Treatment. Treatment of drinking water accounts for about 24% of the total activated carbon used in Hquid-phase apphcations (74). Rivers, lakes, and groundwater from weUs, the most common drinking water sources, are often contaminated with bacteria, vimses, natural vegetation decay products, halogenated materials, and volatile organic compounds. Normal water disinfection and filtration treatment steps remove or destroy the bulk of these materials (75). However, treatment by activated carbon is an important additional step in many plants to remove toxic and other organic materials (76—78) for safety and palatability. 

The technology is primarily applicable to the removal of inorganic fumes, vapors, and gases (e.g., chromic acid, hydrogen sulfide, ammonia, chlorides, fluorides, and SOj) volatile organic compounds (VOC) and particulate matter (PM), including PM less than or equal to 10 micrometers ( m) in aerodynamic diameter (PM,q), PM less than or equal to 2.5 m in aerodynamic diameter (PMj 5), and hazardous air pollutants (HAP) in particulate form (PM ap)-... 

Clark, R. M. (1990). Unit process research for removing volatile organic chemicals from drinking water An overview. In Significance and Treatment of Volatile Organic Compounds in Water Supplies, (N. M. Ram, R. F. Christman, and K. P. Cantor, eds.), Lewis Publishers, Chelsea, ML... 

Removal of hydrocarbons, volatile organic compounds (VOCs), and odors using activated carbon. 

Modification techniques for activated carhon were used to increase the removal capacity by surface adsorption and to improve the selectivity to volatile organic compounds (VOCs). Modified activated carbons (MACs) were prepared by modifying the purified activated carbon with various acids or bases. The effects of adsorption capacity and modified contents on the textural properties of the MACs were investigated. Furthermore, VOC adsorption and desorption experiments were carried out to determine the relationship between the adsorption capacity and the chemical properties of the adsorbents. High adsorption capacity for the selected VOCs was obtained over lwt%-H3P04/AC (lwt%-PA/AC). As a result, MAC was found to be very effective for VOC removal by adsorption with the potential for repeated use through desorption by simple heat treatment. 

A survey of 20 brands of typographical correction fluids found that several contained 10% or less trichloroethylene, although other volatile organic compounds present at higher levels probably posed a greater hazard to people using these products (Ong et al. 1993). Various other consumer products have been found to contain trichloroethylene, such as paint removers, strippers, adhesives, and lubricants (Frankenberry et al. 1987). 

For the charcoal, XAD, and PUF adsorbents discussed above, solvent extraction techniques have been developed for the removal and concentration of trapped analytes. Although thermal desorption has been used with Tenax-GC in some specialized air sampling situations [primarily with sampling volatile organic compounds (EPA, Method TO-17 )], this approach is not a viable alternative to solvent extraction for the charcoal, XAD, and PUF adsorbents. The polystyrene and PUF adsorbents are thermally unstable and the charcoal chemisorption bonding is more easily broken by... 

When granular activated carbons (GAC) are used as the filter media, the GAC filter can also remove dissolved organics (such as TTO, total toxic organics or VOC, volatile organic compounds).1011... 

Soil vapor extraction (SVE) is a relatively new yet widely applied technology for the remediation of soils contaminated with volatile organic compounds (VOC) in the unsaturated zone above the water table (vadose zone). The process consists of generating an airstream through the contaminated soil subsurface in order to enhance the volatilization of organic contaminants and thus remove them from the soil matrix.913... 

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