Neutralization capacity

Neutralization capacity was explained in detail in Section 3.4.1.29. In the analytical chemistry of natural, drinking and service waters the following values of neutralization capacity are usually determined  

The BNC4 5 value is determined by titration of a water sample using a 

The ANCg 3 value is determined by titration of a water sample against HCl having a concentration of 0.1 mol 1 using phenolphthalein as an indicator, or by potentiometric titration. 

In the operational control of the processes of water treatment the term, p-value is used for ANCg 3 in mmol 1 (according to the used phenolphthalein), and ANC4 5 value is designated m-value (Methyl Orange). From 

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When a forest system is subjected to acid deposition, the foliar canopy can initially provide some neutralizing capacity. If the quantity of acid components is too high, this limited neutralizing capacity is overcome. As the acid components reach the forest floor, the soil composition determines their impact. The soil composition may have sufficient buffering capacity to neutralize the acid components. However, alteration of soil pH can result in mobilization or leaching of important minerals in the soil. In some instances, trace metals such as Ca or Mg may be removed from the soil, altering the A1 tolerance for trees. 

Acidification the decrease of acid neutralizing capacity in water or base saturation in soil caused by natural or anthropogenic processes. 

Acid deposition is of greatest concern wherever there are large amounts ol lossil fuel combustion upwind of an area. Eastern North America, large areas of Europe, and eastern Asia all receive acidic deposition. Acidic deposition is especially a concern when poorly buffered soils, with little acid-neutralizing capacity, are impacted. In North America, large areas of eastern Canada, the Adirondack Mountains of upstate New York, and sections of New England all are considered acid sensitive areas, where resistant bedrocks and thin soils prevent significant neutralization of acidity. 

Neutralization capacity, generally relating to carbonic acid... 

The various functional properties of neutralizing amines, such as basicity, neutralizing capacity, DR, and volatility often have little or no direct relationship with each other, but all these properties are significantly different at boiler temperatures. This vital consideration is often insufficiently highlighted in manufacturers data sheets. Consequently, some of the commonly available information comparing amines records data at ambient temperatures, making it next to useless. 

Where amines are employed to counter acidic system water (as when condensate contains carbonic acid) it is necessary to consider the neutralization capacity (NC or C02 absorption value) of the amine. A higher NC means that, for any given concentration, the amine has a greater capacity to neutralize acids. 

The relative neutralizing capacity (RNC) of amines can be calculated from the reaction mole ratios thus, from the reaction of ammonia with carbonic acid, shown here, the RNC is 17/44 = 0.386 ppm neutralizing amine required per ppm C02 ... 

Once neutralization capacity is considered, the next factor is the solubility of amine carbonates formed by neutralization. This characteristic varies by product and temperature. 

Neutralizing capacity functionality is important in lower pressure plants because it is common for some carbon dioxide derived from alkalinity breakdown to be carried over into the steam. It is less important in high-pressure units where demineralized water (or water of similar high purity) is employed because the FW is assumed to be essentially free of alkalinity. 

Neutralizing capacity is not the only measure of a required amine feed rate. Once all acidic characteristics have been neutralized, amine basicity becomes the important issue because this raises the pH above the neutralization point, to a more stable and sustainable level. Consequently, in practice we are concerned with the level of amine necessary to raise the condensate pH to a noncorrosive level. This practical amine requirement is difficult to obtain from theoretical calculations because it must take account of the amine volatility, DR, and the boiler system amine recycling factor (as well as temperature). As noted earlier, the basicity of an amine has little or no relationship to its volatility or DR, so that reliable field results are probably a more important guide in assessing the suitability of an amine product than suppliers tables. 

From a practical perspective, DR (along with neutralization capacity and basicity) is one of the most important functional properties of amines and is always referred to when selecting amines for application in a steam-condensate system. Amine DR values vary considerably, however, and for each amine the DR value changes with variation of temperature and pressure. 

Demand for amine (neutralization capacity) is determined by C02 loading and amine equivalent weight. Polyfunctional amines appear to have a large equivalent weight advantage, but in practice they often have very low volatility and poor thermal stability. 

Table III. Neutralizing Capacity of Anti-helianthin IgG for Helianthin, Kentin and Lysins from Other Sea Anemones ...

IR spectra did not show differences between the intermediate phase and the disordered cancrinite. Therefore, IR techniques fail when were used to identify these phases. One more effective way to identify disordered cancrinite and the intermediate phase is by using X-ray diffraction (XRD). Fig 1 shows the diffractogram of both tectosilicates. In the intermediate phase, the observed peaks correspond with those reported in the literature[4]. The main differences between both spectra correspond to those peaks placed between 25°<20<35°, which are more intense for the disordered cancrinite [9]. Likewise, the results of specific surface area for the intermediate phase (sample 5) and the disordered cancrinite (sample 6) were 35 and 41 m2/g respectively. The antacid capacity test was carried out with the samples 5 and 6. Fig. 2 shows the relationship between experimental pH versus the mass content of the tectosilicates. The neutralization capacity of these solids is related with its carbonate content which reacts with the synthetic gastric juice to neutralize it. In general, the behaviour of solids is similar the pH increases as the weight of the studied solid is increased. However, a less disordered cancrinite mass amount must be employed to reach a pH= 4 in comparison... 

Soil solution equilibrium. Soil solution equilibriumis based on the quantification of acid-neutralizing capacity, ANC, which has been defined as ... 

This equation equals the net input of (sea-salt corrected) base cations minus a critical leaching of acid-neutralizing capacity. 

Writing for short p=pCo2> =Ca2+, y=Z(C02), and label with the subscript r the riverine values. The alkalinity A of a solution (Stumm and Morgan, 1981) is defined as its neutralizing capacity... 

Traditionally, the duration of a toxicity study depends on the intended clinical use and disease duration. The potential immunogenicity of the human protein is a significant issue since antibody binding can partially or completely inhibit the biological activity of that protein, affect its catabolism or alter its distribution and clearance. Any multiple-dose study therefore should include evaluation of the impact of antibody formation, including their neutralizing capacity. However, antibody formation in itself should not be a reason for termination of a toxicity study, particularly if the antibodies are not neutralizing or do not alter the pharmacodynamics of the protein. 

One important application of acid-base titrations is the determination of the alkalinity of various kinds of samples. It is an especially important measurement for the proper treatment of municipal water and wastewater. Alkalinity of a water sample is defined as its acid-neutralizing capacity. It is determined by titrating the water sample with standard acid until a particular pH is achieved. The alkalinity value... 

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