Volatile organic carbons

The commercialization by Kureha Chemical Co. of Japan of a new, highly attrition-resistant, activated-carbon adsorbent as Beaded Activated Carbon (BAC) allowed development of a process employing fluidized-bed adsorption and moving-bed desorption for removal of volatile organic carbon compounds from air. The process has been marketed as GASTAK in Japan and as PURASIV HR (91) in the United States, and is now marketed as SOLD ACS by Daikin Industries, Ltd. 

It is important to identify volatile organic carbon (VOC) and the presence of specific priority poUutants, ia additioa to the total organic content. The... 

Recent air pollution regulations limit the amount of volatile organic carbon (VOC) that can be discharged from wastewater treatment plants. Benzene is a particular case in which air emission controls are required if the concentration of benzene in the influent wastewater exceeds 10 mg/L. 

Fig. 14-5. Schematic diagram of hydrocarbon detection by gas chromatography. NMVOC, nonmethane volatile organic carbon.

Note TRS, total reduced sulfur VOC, volatile organic carbon F, fluorides. 

Dimotakis, E. D., Cal, M. P., Economy, J., Rood, M. J. and Larson, S. M., Chemically treated activated carbon cloths for removal of volatile organic carbons from gas streams - evidence for enhanced physical adsorption. Environ. Sci. Technol., 1995, 29(7), 1876 1880. 

Extends the scope of Health and Safety at Work etc. Act 1974 to include environmentally-hazardous substances including transportation of such dangerous goods and the control of volatile organic carbon emissions from storage and distribution of petrol. 

Finally, there are also pollutants that do not cause direct health impacts hut that may have the potential to cause harm indirectly, through their actions on the overall ecology, or as they function as precursor chemicals that lead to the production of other harmful chemicals. The major indirect-action pollutants include volatile organic carbon (VOC) compounds that act as precursors to more harmful species chemicals called halocarbons and chemicals called greenhouse gases. 

Polluted air often contains carbon monoxide and volatile organic carbon (VOC) gases, including ketones and aldehydes, as well as oxides of sulfur and... 

Autocatalysts, based on monoliths, are probably the most extensively used catalytic reactors around a hundred million have been installed and are performing well in car exhaust systems [10-12]. Reduction of volatile organic carbon (VOC) emissions [13] and removal of NOj, from stationary sources [14, 15] are also... 

As for all of the fractions of organic material in seawater, the volatile organic carbon fraction is defined by the method by which it is collected. In one of the earliest estimates, Skopintsev [93] defined the volatile fraction as the difference between total organic carbon values, as measured by evaporation and dry combustion, when the evaporations were carried out at room temperature and at 60 °C. Thus Skopintsev s volatile fraction consists of those compounds that are volatile from acidified solution taken to dryness at 60 °C but not at 20 °C. This fraction was found to be between 10 and 15% of the total organic carbon. He also noted a 15% difference in measured organic carbon with his dry combustion method when samples were dried at different temperatures and concluded that this difference was due to the loss of volatiles. 

Table 11.3. Averaged volatile organic carbon (VOC) concentrations and VOC total organic carbon (VOC TOC) ratios from different areas [92]...

Table 11.3 presents some typical results obtained by this procedure on seawater samples. MacKinnon [92] concluded that since the volatile organic carbon contents of normal (i.e., unpolluted) seawaters are small, the effect of complete or partial loss of volatile organic components during the determination of total organic carbon in most ocean areas (except highly reducing environments) with either the wet and direct injection methods or dry oxidation methods should be small (about 5%), and within the precision of these methods. 

NAFTA n.a. NEA NEDC NG NGC NGL NGPL NMVOC NOC NUTS North American Free Trade Agreement Not available Nuclear Energy Agency New European Driving Cycle Natural gas Natural gas from coal Natural-gas liquids Natural gas plant liquids Non-methane volatile organic carbons National Oil Company Nomenclature of Territorial Units for Statistics... 

Finally, open ponds used to cool, settle out solids, and store process water can be a significant source of volatile organic carbon emissions. Wastewater from coke cooling and coke volatile organic carbon removal is occasionally cooled in open ponds where volatile organic carbon easily escapes to the atmosphere. In many cases, open ponds can be replaced by closed storage tanks. 

EPA. 1990f. Unvented kerosene heater emissions from mobile homes Studies on indoor air particles, semi-volatile organics, carbon monoxide, and mutagenicity. Research Triangle Park, NC U.S. Environmental Protection Agency, Health Effects Research Laboratory. Report no. EPA/600/D-90/122. 

SPSH has several advantages. It is applicable to sites where contaminants are present as non-aqueous-phase liquids (NAPLs). The technology reduces volatile organic carbon (VOC) removal time to a few weeks for a typical site, whereas soil vapor extraction (SVE) alone requires years for remediation. This reduction in removal time can signrhcantly decrease costs over SVE (from 2 to 10 times). Excavation and ex situ soil treatment is typically much more expensive to implement than SPSH, especially at deep sites. 

The CAV-OX technology offers the following advantages when compared with other technologies that treat volatile organic carbons (VOCs) in water effective at low concentrations, no air emissions, no secondary waste, and VOCs are destroyed. 

---