Ammonium marine sediment

Fernandez et al. [9] used supercritical fluid extraction combined with ion pair liquid chromatography to determine quaternary ammonium in digested sludges and marine sediments. Carbon dioxide modified with 30% methanol was used as the extractant at an operating pressure of 380atm. Between 0.2 and 3.7g kg-1 surfactant was found in Swiss works effluent sludges, determined with a relative standard deviation of 7%. 

Normal-phase HPLC has also found application in the analysis of pigments in marine sediments and water-column particulate matter. Sediments were extracted twice with methanol and twice with dichloromethane. The combined extracts were washed with water, concentrated under vacuum and redissolved in acetone. Nomal-phase separation was performed with gradient elution solvents A and B being hexane-N,N-disopropylethylamine (99.5 0.5, v/v) and hexane-2-propanol (60 40, v/v), respectively. Gradient conditions were 100 per cent A, in 0 min 50 per cent A, in 10 min 0 per cent A in 15 min isocratic, 20 min. Preparative RP-HPLC was carried out in an ODS column (100 X 4.6 mm i.d. particle size 3 jum). Solvent A was methanol-aqueous 0.5 N ammonium acetate (75 25, v/v), solvent B methanol-acetone (20 80, v/v). The gradient was as follows 0 min, 60 per cent A 40 per cent A over 2 min 0 per cent A over 28 min isocratic, 30 min. The same column and mobile phase components were applied for the analytical separation of solutes. The chemical structure and retention time of the major pigments are compiled in Table 2.96. 

Krom, M.D., and Berner, R.A. (1980a) The diffusion coefficients of sulfate, ammonium, and phosphate ions in anoxic marine sediments. Limnol. Oceanogr. 25, 327-337. 

Mackin, J.E., and Aller, R.C. (1984) Ammonium adsorption in marine sediments. Limnol. Oceanogr. 29, 250-257. 

Thamdrup, B., and Dalsgaard, T. (2002) Production of N2 through anaerobic ammonium oxidation coupled to nitrate reduction in marine sediments. Appl. Environ. Microbiol. 68, 1312-1318. 

Dalsgaard, T., and Thamdrup, B. (2002). Factors controlling anaerobic ammonium oxidation with nitrite in marine sediments. Applied and Environmental Microbiology 68, 3802—3808. 

Engstrom, P., Dalsgaard, T., Hulth, S., and AUer, R. C. (2005). Anaerobic ammonium oxidation by nitrite (anammox) Implications for N-2 production in coastal marine sediments. Geochim. Cosmo-chim. Acta. 69(8), 2057—2065. 

Risgaard-Petersen, N., Meyer, R. L., Schmidt, M., Jetten, M. S. M., Enrich-Prast, A., Rysgaard, S., and Revsback, N. P. (2004a). Anaerobic ammonium oxidation in a marine sediment. Aquat. Microb. Ecol. 36, 293-304. 

Morse, J. W., and Morin, J. P. (2005). Ammonium adsorption on coastal marine sediment Influence of redox conditions. Mar. Chem. 95, 107—112. 

Recently research has revealed that nitrification is not exclusively associated with chemoautotrophic bacteria of the P and y proteobacteria, but occurs in many Crenarcheaota as well (Francis et al, 2005 Konneke et al, 2005 Wuchter et al, 2006) who may in fact may dominate this process in seawater (Wuchter et al, 2006) (see Chapter 5 by Ward, this volume). The extent that archael nitrification occurs in coral reef habitats remains to be determined. Ammonium oxidation has also been shown to occur anoxicaUy in some marine sediments at the expense of N02 (Thamdrup and Dalsgaard, 2002) (see Chapter 6, Devol, this volume). 

Penton, C. R., Devol, A. H., and Tiedje, J. M. (2006). Molecular evidence for the broad distribution of anaerobic ammonium-oxidizing bacteria in freshwater and marine sediments. Appl. Environ. Microbiol. 72, 6829—6832. 

Research since 1990 has greatly expanded our understanding of anaerobic metabolism. Novel microorganisms have been discovered, such as those performing anaerobic ammonium oxidation to N2 (anammox). These organisms were predicted to exist based on thermodynamic considerations, but have since been shown to contribute substantially to N2 production in some marine sediments. Organisms that were known to exist for sometime have been shown to perform... 

Bonin P. (1996) Anaerobic nitrate reduction to ammonium in two strains isolated from coastal marine sediment a dissimilatory pathway. FEMS Microbiol. Ecol. 19, 27-38. 

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