Total dissolved nitrogen

Shepherd and Davies [26] have described a semiautomated version of the alkaline peroxodisulfate procedure for the determination of total dissolved organic nitrogen in seawater. These workers carried out experiments on a range of contaminated and clean seawaters using a version [27] of Koroleff s [24] alkaline peroxodisulfate oxidation technique. 

BOD, biochemical oxygen demand COD, chemical oxygen demand TS, total solids TDS, total dissolved solids TVSS, total volatile suspended solids TKN, total Kjeldhal nitrogen BDL, below detectable limit. 

Although the process to determine KlA and K is possible with a spread sheet, it is cumbersome for commercial specifications. The guidehne for the testing of commercial aeration devices has been well developed and is generally available (American Society of Civil Engineers, 1992). There is no requirement to measure total dissolved gas pressure or estimate dissolved nitrogen concentration, and an... 

Soldrzano, L., and Sharp, J. H. (1980a). Determination of total dissolved nitrogen in natural waters. Limnol. Oceanogr. 25,751-754. 

Bronk, D.A., M.W. Lomas, P.M. Glibert, K.J. Schukert, and M.P. Sanderson. 2000. Total dissolved nitrogen analysis Comparisons between the persulfate, UV and high temperature oxidation methods. Mar. Chem. 69 163-178. 

Figure 8.2 Regression of total (dissolved and particulate) nitrogen and phosphorus from estuaries, surface films, and oceanic surface (< 50 m) and deep waters. (Modified from Downing, 1997.)...

Table 10.4 Total dissolved nitrogen (TDN) and organic nitrogen (DON) in estuaries and rivers. 

Karl, D.M., Tien, G., Dore, J., and Winn, C.D. (1993) Total dissolved nitrogen and phosphorus concentrations at United States-JGOFS station ALOHA—Redefield reconciliation. Mar. Chem. 41, 203-208. 

Fig. 7.11 Nitrogen balance during the H2O2-UV treatment ofEDTA (QoHt6N208). DN dissolved total nitrogen, DIN dissolved inorganic nitrogen, DON dissolved organic nitrogen. DN was calculated according to DN = ELi

The fluxes illustrated in Fig. 17.3 reveal several important aspects of N cycling in the Amazon River/ocean mixing zone. First, the external supply of biologically available dissolved nitrogen (totalling 10-12 x 10 mol d, including N fixation) is considerably... 

Figure Z(.3 Seasonal maps showing the potential for nitrogen fixation in the world oceans. Maps were generated by converting global dust iron fluxes to total dissolved iron and using the relationship shown in between log[Fe ] and nitrogen fixation maximum nitrogen fixation. From Berman-Frank ctaf., 2001 (Fig.4.6) with permission.

Open ocean regions receive significant amounts of land-based N from atmospheric deposition ( 25 Tg N yr Dentener pers. comm.). This estimate of atmospheric deposition does not include dissolved organic nitrogen (DON), which may account for from 20% to as much as 80% of the total dissolved N in rainwater in remote marine locations (Cornell et al., 1995, 2001, 2003 Mace et al. 2003). Keeping in mind that this estimate of DON is uncertain because of the... 

Figure 16.20 Nitrogen-to-phosphorus (N P) ratios at Station ALOHA. (A) Depth profiles of N P forinorganic (NO3 P04 ) and total (TDN TDP) pools showing fundamentally different depth trends relative to the 16N 1P Redfield ratio, which is shown as a vertical dashed line in each plot. The elevated N P (>16) for the total dissolved pool, especially in the upper 100 m of the water column, indicates an excess of N relative to the P requirements for biomass production, if all DON and DOP are biologically available.The middle plot shows the depth dependence for the stoichiometric relationships if the DON and DOP pools are corrected for residual deep water concentrations (DON = 2.23 pM and DOP = 0.04 pM, respectively) to remove the contribution of the recalcitrant pools. After this correction, the near-surface N P appears to converge near the Redfield ratio with a broader envelope of values near the surface. This stoichiometry of the DOM pool may be an important factor in the selection for, or against, N2 fixing microorganisms. From Karl et al. (2001a).

Table i8.i Concentrations of Total Dissolved Nitrogen (TDN) and Dissolved Organic Nitrogen (DON) from Surface Waters of a Variety of Estuarine Systems... 

Table 26.5 Proportion of total dissolved nitrogen (TDN inorganic+organic) excreted as DON (the key below denotes how % TDN excreted as DON was measured for each study)... 

---