Alkalinity carbonate

The results given for HCO are actually values of the carbonate alkalinity expressed as though it were all HCO . ... 

Water from cooling tower pump suction, pH 8.6-8.8, pressure 20-30 psi (140-210 kPa), flow 2-5 ft/s (0.2 to 1.5 m/s). Dispersant, 1-3 ppm tolyltriazole, sodium hypochlorite 2 hr/day to 0.8 free residual chlorine 0.6-0.8 ppm total zinc and 0.1-0.2 ppm soluble zinc. Free chlorine maintained at 1 ppm for 5 consecutive days/month during the summer. Chemical treatment started after 2 years of no treatment. Water conductivity -612 ( imhos/cm), turbidity 27 NTU (nephelometric turbidity units), chloride 110 ppm, sulfate 50 ppm, carbonate alkalinity (CaCOa) 27 ppm, bicarbonate alkalinity (CaCOs) 118 ppm... 

Lime is somewhat different from the hydrolyzing coagulants. When added to wastewater it increases pH and reacts with the carbonate alkalinity to precipitate calcium carbonate. If sufficient lime is added to reach a high pH, approximately 10.5, magnesium hydroxide is also precipitated. This latter precipitation enhances clarification due to the flocculant nature of the Mg(OH)2. Excess calcium ions at high pH levels may be precipitated by the addition of soda ash. The preceding reactions are shown as follows ... 

The demand for electrically operated tools or devices that can be handled independently of stationary power sources led to a variety of different battery systems which are chosen depending on the field of application. In the case of rare usage, e.g., for household electric torches or for long-term applications with low current consumption, such as watches or heart pacemakers, primary cells (zinc-carbon, alkaline-manganese or lithium-iodide cells) are chosen. For many applications such as starter batteries in cars, only rechargeable battery systems, e.g., lead accumulators, are reasonable with regard to costs and the environment. 

Where FW contains bicarbonate or carbonate alkalinity (as calcium, magnesium, or sodium salts), these salts undergo thermal decomposition in the boiler, and the steam-volatile contaminant gas carbon dioxide is introduced into the steam distribution system, as shown ... 

Some older plants still carry this softening process further by the addition of mono- or di-sodium phosphate and, although it lowers the hardness to only a few ppm, it ultimately results in additional carbonate alkalinity, which is undesirable. Additionally, the phosphate is too expensive and it is better to simply pass the filtered, lime-treated water through a BX softener. 

NOTE If caustic is added before the degasser, sodium carbonate alkalinity is produced. 

Under BW temperature conditions, this first-stage decomposition reaction proceeds to 100% completion, producing carbonate alkalinity and carbon dioxide. Thus, 1 ppm of bicarbonate initially produces 0.44 ppm of carbon dioxide. 

Boiler pressure Bicarbonate alkalinity starting point 1 ppm carbonate (as CaC03) produces the following ppm of CO2 Carbonate alkalinity starting point 1 ppm carbonate (as CaC03) produces the following ppm of CO2... 

Carbonate and phosphate control is vital. If a minimum carbonate alkalinity of 250 mg/1 expressed in terms of CaC03 is consistently maintained when carbonate control or sodium ion exchange softening is used, a residual of soluble phosphate need not be maintained. A residual of soluble hardness up to 5 mg/1 expressed in terms of CaC03 is then usually found in the BW, but scale formation may be minimized by phosphate or carbonate conditioning treatment. 

Maintenance of a phosphate reserve is not essential provided that a minimum carbonate alkalinity of 250 mg/kg can be maintained, depending on the alkalinity of the FW and the working pressure of the boiler, or that an appropriate program of transporting polymers is employed. 

Zirconium reduces almost all oxygen-containing salts. This is the case for alkali hydroxides (accidents with the lithium, sodium and potassium compounds) and zirconium hydroxide, lithium, sodium and potassium carbonates, alkaline sulphates sodium tetraborate and copper (II) oxide. This is true especially for oxidising salts such as alkaline chromates and dichromates, chlorates (accident with potassium salt) and nitrates (accident with potassium salt). 

All of these measures of saturation are very useful in predicting the geographic distribution of sedimentary carbonates. For example, sediments lying below waters that are undersaturated with respect to calcite should be devoid of calcareous oozes. Since direct measurement of [COj ] observed difficult, its concentration is usually computed from two more easily measured parameters, the carbonate alkalinity and pH of a seawater sample. 

THE EFFECT OF POC AND PIC FORMATION AND DEGRADATION ON THE pH, CARBONATE ALKALINITY, AND XCO2 OF SEAWATER... 

Vertical concentration profiles of (a) temperature, (b) potential density, (c) salinity, (d) O2, (e) % saturation of O2, (f) bicarbonate and TDIC, (g) carbonate alkalinity and total alkalinity, (h) pH, (i) carbonate, ( ) carbon dioxide and carbonic acid concentrations, and (k) carbonate-to-bicarbonate ion concentration ratio. Curves labeled f,p have been corrected for the effects of in-situ temperature and pressure on equilibrium speciation. Curves labeled t, 1 atm have been corrected for the in-situ temperature effect, but not for that caused by pressure. Data from 50°27.5 N, 176°13.8 W in the North Pacific Ocean on June 1966. Source From Culberson, C., and R. M. Pytkowicz (1968). Limnology and Oceanography, 13, 403-417. 

Carbonate alkalinity The concentration of negative charge in seawater contributed by bicarbonate (HCO3) and carbonate (COj ). It is usually reported in units of meq/L. 

In the total inorganic carbon balance of equation 8.94, we neglected the presence of some species. Table 8.9 shows that this approximation is reasonable although, for accurate calculations, we should also have considered bicarbonates CaHC03 and MgHCO and the soluble carbonate CaCO . Note also that sulfates occur in negligible molar proportions and that carbonate alkalinity coincides with total alkalinity. 

The HCO amount listed in table 8.28 actually represent carbonate alkalinity, calculated neglecting CO ". The alkalinity [Aik] of a solution represents its capacity to neutralize strong acids in solution. Alkalinity can be defined as the sum of equivalents of all species whose concentrations depend on the concentration of ions in solution, minus the concentration of ions in solution. For a solution containing borates and carbonates, alkalinity can be expressed as... 

Figure 8.35 shows the redox state and acidity of the main types of seawaters. The redox state of normal oceanic waters is almost neutral, but they are slightly alkaline in terms of pH. The redox state increases in aerated surface waters. Seawaters of euxinic basins and those rich in nutrients (eutrophic) often exhibit Eh-pH values below the sulfide-sulfate transition and below carbonate stability limits (zone of organic carbon and methane cf figure 8.21). We have already seen (section 8.10.1) that the pH of normal oceanic waters is buffered by carbonate equilibria. At the normal pH of seawater (pH = 8.2), carbonate alkalinity is 2.47 mEq per kg of solution. 

LaFlamme BD, Murray JW. 1987. Solid/solution interaction The effect of carbonate alkalinity on adsorbed thorium. Geochim Cosmochim Acta 51 243-250. 

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. 

At the present time, a large number of spent batteries are disposed of directly into the urban waste stream without proper controls. In addition to the most common systems such as zinc-carbon, alkaline manganese and nickel-cadmium, these now include, at an increasing rate, nickel-metal hydride and lithium cells. Such disposal is of serious concern because of the possible effects of battery components on the environment. Consequently, most countries are now evolving policies for collection and recycling. The majority of lead-acid batteries are recycled, but the number of recycling plants in operation worldwide for other battery systems is still very small due to the unfavourable economic balance of such operations (see Table A3.1). Some of the procedures for the disposal and recycling of battery materials are now briefly described. 

The first important step is that of putting the sample (unknown) into solution. For metals and alloys, strong acids, such as HCI, HNCE, or aqua regia may be used. If the material is not fully dissolved by these adds, it should be fused, either with sodinin carbonate (alkaline fusion) or potassium add sulfate (acid fusion). Care should be exercised to make certain that no portion of the unknown is volatilized and thus lost during these procedures. 

The procedure used to define an equilibrium model is to (1) define all the variables and (2) define independent equilibria as a function of phase equilibria. The variables are defined as the chemical parameters typically measured in water chemistry. For the major constituents and some of the more important minor constituents, these are calcium, magnesium, sodium, potassium, silica, sulfate, chloride, and phosphate concentrations as well as alkalinity (usually carbonate alkalinity) and pH. To this list we would also add temperature and pressure. The phase equilibria are defined by compiling well-known equilibria between gas-liquid phases and solid-liquid equilibria for the solids commonly found forming in nature in sedimentary rocks. Within this framework, one can construct different equilibrium models depending upon the mineral chosen actual data concerning the formation of specific minerals therefore must be ascertained to specify a particular model as valid. 

Acid treatment to reduce caustic and carbonate alkalinity ... 

Carbonate alkalinity. When P is 1/2 T or less (but greater than 0), carbonate alkalinity is equal to 2P on the other hand, when P >1/27) the alkalinity due to C032- = 2(T-P). 

When the total hardness measured in the sample is numerically greater than the sum of both carbonate alkalinity and bicarbonate alkalinity, then... 

Carbonate hardness = carbonate alkalinity + bicarbonate alkalinity... 

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