Carbon burial efficiencies

Some component of the terrestrial POM must be extremely nonreactive to enable a higher burial efficiency as compared to autochthonous POM. A possible candidate for this nonreactive terrestrial POM is black carbon. This material is a carbon-rich residue produced by biomass burning and fossil fuel combustion. Some black carbon also appears to be derived from graphite weathered from rocks. It is widely distributed in marine sediments and possibly carried to the open ocean via aeolian transport. 

Carbon and Phosphorus Burial Efficiencies. The estimate of diatom carbon demand (12-15 g/m2 per year) is consistent with the flux of carbon to the sediment surface. With sediment-trap fluxes corrected for resuspension, we measured a total annual deposition flux of 12.5 g of C/m2. In comparison, Eadie et al. (24) obtained 23 g of C/m2 for a 100-m station, based on three midsummer metalimnion deployments. Of our total, 83% of the carbon was associated with diatoms, and the primary diatom carbon flux was 10.3 g of C/m2. Thus, about 15-30% of the diatom carbon was regenerated in the water column during sedimentation. Approximately 10% of the diatom flux reached the sediment surface encapsulated in copepod fecal pellets the remaining 90% was unpackaged. 

Betts J. N. and Holland H. D. (1991) The oxygen content of bottom waters, the burial efficiency of organic carbon, and the regulation of atmospheric oxygen. Global Planet. Change 5, 5-18. 

The process of adsorption on carbon is applicable to wastewaters and polluted air. Treated waters may be suitable for reuse in industrial processes and can be discharged safely to the sewer system if removal efficiencies are high enough. Hazardous constituents of no commercial value that are removed may be disposed in burial sites after they have been stabilized. The high capacity of activated carbon for many compounds is attributable to the large surface area of the carbon (500-1500 m2 g-1). 

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