Concentrations of Dissolved Nitrogen

The NO3 content of upweUing water is strongly influenced by the location of a system (Codispoti et al., 1982) in the global oceanic conveyer belt that transports deep water through the ocean basins (Broecker and Peng, 1982, their Fig. 1.12). From the North Atlantic to the Pacific and Indian Oceans through the Antarctic Circumpolar Current, there are increasing nutrients, from the faUout of surface productivity. 

UpweUed NO3 concentrations are usuaUy reduced during El Nino conditions (e.g. Corwith and Wheeler, 2002), by as much as 50% in the upweUing areas of Peru (e.g., data for 1976) and Baja California (e.g., in 1972) (Wilkerson et at., 1987). Point Conception, California in the El Nino year 1983 experienced about a 30% 

DON concentrations of 4-8 pM have been observed in the relatively weak upweUing area off the northwest coast of Spain (Alvarez-Salgado et al., 1999). HUl and Wheeler (2002) reported values of 7 pM DON in upweUed waters off the Oregon coast. These are similar DON concentrations to the open ocean as summarized Table 17.3 of HiU and Wheeler (2002). Some of this DON is upweUed e.g., water at 50 m depth off Oregon had a mean value of 5.98 (HUl and Wheeler, 2002). Another source is from production by phytoplankton as they partition newly assimilated NO3 into particulate nitrogen and DON that is released (Bronk et al., 2006 Wetz and Wheeler, 2003). 

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It follows from the equation (3.28) that the liquid technique to determine concentration of dissolved oxygen or oxygen of extraneous gases being analyzed (nitrogen, hydrogen, inert gases, hydrocarbons, etc.) which are in equilibrium with liquid polar solvent (water, alcohols, etc.), is applicable as well. This means that relation... 

Jasper JP, Hayes JM, Mix AC, Prahl EG (1994) Photosynthetic fractionation of C-13 and concentrations of dissolved C02 in the central equatorial Pacific, Paleoceanography 9 781-798 Javoy M, Pineau F, Delorme H (1986) Carbon and nitrogen isotopes in the mantle, Chem Geol 57 41-62... 

Unsteady-State Mass Balance Method One widely used technique for determining Kj a in bubbling gas-liquid contactors is the physical absorption of oxygen or COj into water or aqueous solutions, or the desorption of such a gas from a solution into a sparging inert gas such as air or nitrogen. The time-dependent concentration of dissolved gas is followed by using a sensor (e.g., for O2 or CO2) with a sufficiently fast response to changes in concentration. 

In the bleaching column, warm air strips the nitrogen tetroxide out of the red acid to give a product acid completely free of dissolved nitrogen oxides. The red acid enters the top of the column at 45°C and the secondary bleaching air enters the bottom of the column at 80°C. The final product leaves the bottom of the bleaching column at a concentration of 60% wt. nitric acid (40% water). The same type of... 

Michalzik, B., K. Kalbitz, J. H. Park, S. Solinger, and E. Matzner. 2001. Fluxes and concentrations of dissolved organic carbon and nitrogen — a synthesis for temperate forests. Biogeochemistry 52 173-205. 

Waldrop, M. P, and Zak, D. R. (2006). Response of oxidative enzyme activities to nitrogen deposition affects soil concentrations of dissolved organic carbon. Ecosystems 9(6), 921-933. 

Seawater contains about 3.5% salts, in which the content of sodium chloride is about 80%. The concentration of dissolved salts as well as temperature and pressure influence the physical properties of seawater. The total salt concentration is usually called salinity . Salinity is generally measured by the electrical conductivity or determination of chloride content. At present, salinity(S) is defined as S = 1.80655 Cl (Cl is the concentration of chloride in seawater) [5]. Dissolved oxygen and silica are usually measured as additional parameters to characterize seawater. The concentrations of nitrogen and phosphorus are the indices of nutrients and measure the fertility and production of the oceans. 

FJ/5(5 - 2FJ = (2r - 3q)/25r is the number of mmol/L of ammonia nitrogen produced per nunol/L of dissolved oxygen. We have said the / is the concentration of dissolved oxygen left after the aeration is cut off This may be assumed as all consumed, since the process is now going toward being completely anaerobic. Therefore, the nunol/L of ammonia nitrogen produced in the heterotrophic side reaction is... 

A domestic wastewater with a flow of 20,000 m /d is to be denitrified. The effluent from the nitrification tank contains 30 mg/L of NO3-N, 2.0 mg/L of dissolved oxygen, and 0.5 mg/L of NO2-N. The concentration of total nitrogen in the effluent is 2.53 mg/L. Assuming all kinetic parameters are known, calculate the fraction of nitrate nitrogen destroyed in the denitrification process. 

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