Deep carbon transfer

Fe has been shown to play a key role in limiting phytoplankton growth and carbon uptake, and in determining the phytoplankton community structure in the Southern Ocean. Therefore, the carbon transfer efficiency to deep water by the biological carbon... 

Transfer 30 g. of the hydrochloride to a 500 ml. separatory funnel, add 100 ml. of water and shake until a thin paste of uniform consistency is obtained add 10 per cent, aqueous sodium hydroxide solution in the cold with shaking until the whole mass has become bright green (the colour of the free base) and the mixture has an alkaUne reaction. Extract the free base by shaking with two 60 ml. portions of benzene (1). Dry the combined benzene extracts with a Uttle anhydrous potassium carbonate, and filter into a distiUing flask fitted with a water condenser. Distil off about half of the benzene, and pour the residual hot benzene solution into a beaker. Upon cooUng, the p-nitrosodimethylaniUne erystallises in deep green leaflets. Filter these off and dry them in the air. The yield of p-nitrosodimethylaniUne, m.p. 85°, from the hydrochloride is almost quantitative. 

A deep pool of ethanol is suddenly exposed to an atmosphere of pure carbon dioxide and unsteady state mass transfer, governed by Fick s Law, takes place for 100 s. What proportion of the absorbed carbon dioxide will have accumulated in the 1 mm layer closest to the surface in this period ... 

Electrochemical destruction of organics can be an economically viable alternative to incineration, carbon beds, bioremediation, deep well disposal and other methods as destruction to very low acceptable levels is possible [227a], Electrochemical techniques are in fact superior to incineration or deep well disposal as it is a final solution and not a transfer of a toxic material from one environment to another, e.g. to the groundwater or the atmosphere [285], Common destruction pathways include both direct and indirect electrolysis. Many electrochemical degradation pathways remain unclear and may be a mixture of direct and indirect processes depending on the pollutant and its intermediates [84,285a]. 

From a geochemical perspective, sinking POM is an important mechanism by which carbon and other elements are transferred from the sea surfece into the deep sea and onto the sediments. This transport is termed the biological pump and includes the sinking of inorganic particles that are of biogenic origin, namely calcium carbonate and silicate shells. 

Current theories on their genesis revolve around a mechanism of mass gas transfer of material rich in carbonate derived from the upper mantle deep within the earth. The three most significant commercial carbonatite deposits are at Mountain Pass, California in the U.S.A., Palabora in South Africa and Paotou, Inner Mongolia in the Peoples Republic of China, see Figure 4. 

The mean residence time of carbon in the mixed layer of the sea before transfer into the deep sea is of considerable interest, for as has already been pointed out, the rate of this transfer will eventually govern the levels of excess 14C in the atmosphere. There have been several estimates of this residence time. Craig (29) concluded that it was most probably not more than 10 years, and in one of his calculations he deduced a value of 4 years. Broecker et al. (14) concluded it was 5 years in the Atlantic Ocean and 8 years in the Pacific Ocean. Nydal (45) found that for the North Atlantic it was around 3 years or less. The profiles of Figure 6, and a few others which are not shown, all show a significant penetration of excess 14C below the mixed surface layer, pointing to a short residence time, of the order of 2 years, in the mixed layer of the sea before transfer below the thermocline into the deep sea. Considering the size of the oceans these data are very meager, and no firm conclusions can be drawn from them. However, continued measurements of 14C in the sea should help to establish a firmer estimate of this quantity. 

---