Inorganic dissolved species

Isotopic Characterization of Humic Colloids and Other Organic and Inorganic Dissolved Species in Selected Groundwaters from Sand Aqnifers at Gorleben, Germany... 

The carbon content of the oceans is more than 50 times greater than that of the atmosphere. Over 95% of the oceanic carbon is in the form of inorganic dissolved species, bicarbonate (HCOj) and carbonate (CO3-) ions the remainder exists in various forms of organic carbon (Druffel et al. 1992). Oceanic uptake of C02 involves three steps (1) transfer of C02 across the air-sea interface, (2) chemical interaction of dissolved C02 with seawater constituents, and (3) transport to the deeper ocean by vertical mixing processes. Steps 2 and 3 are the rate-determining processes in the overall transfer of C02 from the atmosphere to the ocean, and oceanic transport and mixing processes are the primary uncertainties in predicting the rate of oceanic uptake of C02. 

In Chapter 5. we noted that COj readily dissolves in seawater to form several inorganic carbon species. TDIC is defined as the sum of the concentration of those species, i.e., the sum of the carbonate, bicarbonate, carbonic acid, and carbon dioxide concentrations. 

Coprecipitation ot Pb2" with BaS04 from distilled water at pH 2. [Data from N. Mlkac and M. Branica, Separation of Dissolved Alky Head and Inorganic Lead Species by Coprecipitation with BaS04. Anal. Chim. Acta 1988.212.349]... 

Since NaOH is used to dissolve aerosil-200 silica into soluble inorganic silicate species, Na+/Si ratio plays an important role on the formation of a typical MCM-41. When NaOH is not used, only amorphous phase is obtained even if the Na+/Si ratio is... 

In addition to the soluble chemical species and possible solid phase species described in the previous sections no discussion on speciation can be complete without the consideration of surface species. These include the inorganic and organic ions adsorbed on the surface of particles. Natural systems such as soils, sediments and waters abound with colloids such as the hydrous oxides of iron, aluminium, manganese and silicon which have the potential to form surface complexes with the various cationic and anionic dissolved species (Evans, 1989). 

A detailed review of the stabilities of inorganic selenium species, i.e. Se and Se, in water has been published (Heninger et al., 1997). No loss of either species was detected in aqueous solutions stored at — 20°C for 1 year. The concentrations studied were 10 and SOngmF1 (Cobo et al., 1994). Losses of Se occurred at higher temperatures for solutions of pH 2 and 6 stored in polyethylene containers. The maximum time for preservation was 1-2 months. In another investigation (Heninger et al., 1997), aqueous samples stored in Teflon containers at 4°C lost 29% of Se by oxidation in less than 1 month. The authors stated that catalytic oxidation of Se had occurred as a result of chlorine produced by a reaction between dissolved chloride and oxygen. 

Volkov II, Rozanov AG, Demidova TP (1992) Reduced inorganic sulphur species and dissolved manganese in the water of the Black Sea. In Vinogradov ME (ed) Winter state of the ecosystem of the open part of the Black Sea, Shirshov Institute of Oceanology RAS, Moscow, p 38 (in Russian)... 

The average concentrations of reduced inorganic sulfur species in the anoxic zone of the Black Sea measured using a new colorimetric method developed by Volkov [61,62] are summarized in Table 3. Presented elemental sulfur data refer to the stun of elemental sulfur allotropes (zero-valent sulfur) and the zero-valent sulfur derived from some fraction (n - 1) of the original polysulfide S 2. Thiosulfate data in the table represent the total amount of thiosulfate, sulfite, and polythionates. At some stations in the Black Sea, Volkov [61] observed a concentration maximum of elemental sulfur at the oxic/anoxic interface associated with sulfide oxidation by dissolved oxygen and/or Mn oxyhydroxides. Increasing with depth, elemental sulfur concentrations are probably explained by the ongoing process of polysulfide formation... 

The analytical activity of dissolved inorganic carbon species can be written as the sum of undissociated and dissociated acid species (3.54). For a closed system, the value of C is constant over the entire pH range. 

Alkalinity is an important parameter in assessing the elfects of environmental change on aqueous systems (see Section 3.3.4.1). It is also important to understand that, by definition, alkalinity (Equation (3.61)) is independent of addition or removal of CO2 (or H2CO3) from the system (c/ Equation (3.62) - H2CO3 does not appear in the charge balance expression). This can be very useful in the determination of the concentration of dissolved inorganic carbon species in aqueous systems that are in equilibrium with an atmosphere containing C02(g) (Example 3.7). 

Unlike DOC, which can be easily differentiated from dissolved inorganic C (DIC), DON is calculated by subtracting the concentrations of nitrate, nitrite, and ammonia from total dissolved N (TDN). This technique introduces several errors to estimates of DON concentration, and robust marine DON concentrations are a relatively recent phenomenon (Sharp et al., 2004). Methods for quantifying each of these N pools are discussed in McCarthy and Bronk (this volume). Contemporary studies often omit the filtration step that differentiates dissolved organic matter (DOM) from particulate organic matter (POM) because DOM is far more abundant even in surface waters. Therefore, reported concentrations often represent total organic N (TON) rather than simply the dissolved species. 

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