Carbon soil emission

Raich JW, Potter CS (1995) Global pattern of carbon dioxide emission from soil. Global Biogeochem Cy 9 23-36... 

Carbon dioxide emissions from the agricultural sector in OECD countries are estimated at less than 1% of overall COj emissions (IPCC 2001). Net emissions of CO, from agriculture depend upon the direct and indirect use of fossil fuels, and on the amount of carbon sequestration in soil organic matter and crop growth (Shepherd et al. 2003). 

Raich, J W., and Potter, C. S. (1995). Global patterns of carbon dioxide emissions from soils. Global Biogeochem. Cycles 9(1), 23-36. 

ENHANCED BIOGENIC SOIL EMISSIONS OF NITROGEN AND CARBON GASES A POSTFIRE EFFECT... 

Steudler PA, Melillo JM, Ferry E, et al. 1987. Carbonyl sulfide and carbon disulfide emissions from temperate and boreal forest soils [Abstract], Abstr Pap Am Chem Soc 194 ENVR 268. 

The largest amount of emitted species are based on carbon itself (see Chapter 2.7.3 and Table 2.30). Care should be taken when using emission values denoted as terrestrial emission because it is probably the sum of plant (vegetation) and soil emission. 

While production of most bioplastics results in reduced carbon dioxide emissions compared to traditional alternatives, there are some real concerns that the creation of a global bioeconomy could contribute to an accelerated rate of deforestation if not managed effectively. There are associated concerns over the impact on water supply and soil erosion and bioplastics represent a 42% reduction in carbon footprint. On the other hand, bioplastic can be made from agricultural byproducts and also from used plastic bottles and other containers using microorganisms. 

The vacuum extraction process involves using vapor extraction wells alone or in combination with air injection wells. Vacuum blowers are used to create the movement of air through the soil. The air flow strips the VOCs from the soil and carries them to the surface. Figure 18.14 shows the flow diagram for such a process. During extraction, water may also be extracted along with vapor. The mixture should be sent to a liquid-vapor separator. The separation process results in both liquid and vapor residuals that require further treatment. Carbon adsorption is used to treat the vapor and water streams, leaving clean water and air for release, and spent GAC for reuse or disposal. Air emissions from the system are typically controlled by adsorption of the volatiles onto activated carbon, by thermal destruction, or by condensation. 

The enhanced volatilization process is operated by putting contaminated soil in contact with clean air in order to transfer the contaminants from the soil into an air stream. The air stream is further treated through the use of carbon canisters, water scrubbers or afterburners to reduce air emission impacts. Four methods are available that can achieve this effect19 ... 

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. 

Aerts R, Toet S. Nutritional controls of carbon dioxide and methane emissions from Carex-dominated peat soils. Soil Biol. Biochem. 1997 29 1683-1690. 

Fernandez-Luqueno F, Reyes-Varela V, Cervantes-Santiago F, Gomez-Juarez C, San-tillan-Arias A, Dendooven L.Emissions of carbon dioxide, methane and nitrous from soil receiving urban wastewater for maize Zea mays L.) cultivation. Plant Soil. 2010 331 203-215. DOI 10.1007/slll04-009-0246-0... 

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