Influence inorganic carbon

The potentiometric titration was carried out in order to determine the functional groups present in the biomass surface. During the titration experiments, the C02-free condition was always maintained to avoid the influence of inorganic carbon on the solution pH. Detailed potentiometric titration procedure and estimation method of functional groups are available in the previous reports [4,6]. 

The relevance of the pH-value was already seen in the chain reaction of ozone, especially in the initiation step. It also plays an important role in all the acid-base equilibrium by influencing the equilibrium concentrations of the dissociated/nondissociated forms. This is especially important for the scavenger reaction with inorganic carbon, which will be discussed further in Section B 4.4.4. 

Inorganic carbon can also influence the total reaction rate by acting as a scavenger for hydroxyl radicals, whereas ozone itself does not react with carbonate or bicarbonate (Hoigne, 1984). The reaction of OH° with inorganic carbon proceeds according to the following mechanisms ... 

The reaction rate constants for the inorganic carbon reactions are summarized in Table 4-4. A comparison of both reactions shows that carbonate is a much stronger scavenger than bicarbonate. This indicates that the pH-value, which influences the form and concentration of inorganic carbon present (pKa (HC037C032 ) = 10.3), is of major importance in determining the effect inorganic carbon has on the reaction rate. 

In the following first example the liquid ozone concentration and the OH-radical concentration are calculated with semi-empirical formula from the mass balance for ozone (Laplanche et al., 1993). For ozonation in a bubble column, with or without hydrogen peroxide addition, they developed a computer program to predict the removal of micropollutants. The main influencing parameters, i. e. pH, TOC, U V absorbance at 254 nm (SAC254), inorganic carbon, alkalinity and concentration of the micropollutant M are taken into consideration. 

Sharkey T. D. and Berry J. A. (1985) Carbon isotope fractionation of algal as influenced by an inducible CO2 concentrating mechanism. In Inorganic Carbon Uptake by Aquatic Photosynthetic Organisms (eds. W. J. Lucas and J. A. Berry). American Society of Plant Physiologists, pp. 389-401. 

Many chemical processes occur in water. They are influenced by the action of algae and bacteria in water. For example, algal photosynthesis fixes inorganic carbon from HCO3 ion in the form of biomass in a process that also produces C032 ... 

In addition to the biological factors noted above, the isotopic composition of inorganic carbon is influenced by the exchange of carbon between surface waters and the atmosphere. Carbon isotopes are fractionated with the transfer of carbon between water and the atmosphere (Siegenthaler and Munnich 1981 Zhang et al. 1995), with equilibrium fractionation resulting in atmospheric carbon dioxide about 8%o depleted relative to the ocean. This effect is temperature dependent, with a change in fractionation of approximately -0.1%o per K (Mook 1986). Thus, at equilibrium, DIC in colder waters is enriched in C relative to warmer waters. In natural waters, the time required for isotopic equilibration is slow relative to the residence time of carbon in surface waters... 

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