Base consumption acidity

The base consumption of a water is defined as that quantity of sodium hydroxide solution in mmol/1 which is consumed during titration up to certain pH values or to the transition points of certain indicators. If titration is carried out electrometrically to pH 4.3 or methyl orange or a mixed indicator are used, the base consumption given is the negative m value. If titration is carried out electrometrically to pH 8.3 or a phenol-phthalein indicator is used, base consumption is the negative p value. 

The base consumption of natural waters is principally caused by the carbon dioxide dissolved in the water. It may also be brought about, however, by 

Pipette 100 ml of the sample into the titration vessel, which is equip- 

Add 5 drops of methyl orange indicator (or mixed indicator) to 100 ml 

If a yellow coloration occurs instead of a reddish (or violet) colora- 

---

TEM observations have confirmed that large hexagonal plates of green rust form at the expense of ferrihydrite (Mann et al., 1989). The reaction is accompanied by production of an equivalent amount of protons (shown by the consumption of alkali to maintain conditions around neutral) and the loss of Fe " and the respective anion (Cr, S04 ) from solution (Fig. 13.6). For the reaction to proceed it is essential that the acid produced during the process is continuously neutralized and that a pH dose to neutral is maintained (see the base consumption in Figure 13.6). In the Cl-system, Lewis (1997) observed a fairly constant [Fe " ] during much of the reaction and a... 

By far the most important biological controls on calcification are those which influence the equilibrium between the inorganic carboxy species (Chapter 2.1, p. 32). This may result from the consumption of CO2 in photosynthesis, chemosynthesis and heterotrophic CO2 fixation the release of CO2 during respiration and fermentation and from the production of bases and acids due to varied metabolic activities. 

The most common titrations are based on acid-base neutralisation (acid-base titration), or oxidant-reductant reaction (redox titration) principles. With these two titration methods, many textile chemicals can be analysed. The common indicators used in these titrations are listed in Table 4.U and 4.2. For an accurate titration, the consumption of the standard solution is ideally between 35 and 45 ml in a 50 ml burette. 

The selective oxidation of D-glucose into gluconic acid was selected as catalytic test reaction. The reactor vessel and the experimental conditions were described in detail elsewhere [8]. The pH of the reaction mixture was kept at a constant value in the range 9.25-9.45 by adding a 20 wt.% aqueous solution of sodium hydroxide with an automatic titrator (Stat Titrino 718) from METROHM. The base consumption was recorded as a function of time. 

Acid-containing wastes are produced in many industries. Thus, in leaching of minerals, in regeneration of cation exchangers, and in metal surface treatment, only a part of the acid is utilized (due to the reduced activity at the lower acid concentration). The acids plus salts comprising aqueous solutions formed in these operations as well as in others (e.g., zinc electrowinning) are neutralized in most cases and disposed of. Efficient separation and recovery of the acid values is more beneficial, as it would save on acid and base consumption, reduce discharge of solution or solids, and enable recovery of other valuable components (e.g., metal values) from the deacidified solutions. 

Acid-base-coupled extractants seem to be very attractive for many industrial applications. They allow recovery of acids from waste streams instead of neutralization. Acid and base consumption is thereby reduced, as is the amount of waste to be disposed of. Being also excellent extractants for metal salts, ABC extractants provide for sequential recovery of acids and their salts from waste streams. The extractant composition can be adjusted so that a single extractant can extract first the acid and then the salt at high efficiency, selectivity, and reversibility. Because of this high reversibility, these components are recovered by back-extraction with water, at concentrations approaching those in the feed stream and in some cases even higher. 

The evaluation of experimental data is problematic, because the overall acid and base consumption is measured and the reactions taking place in parallel with sxuface charging cannot... 

A challenging goal in RE separation is to develop an effective process to enhance separation and minimize environmental pollution. But what is the satisfied dilute and extractant The desired dilute should be nonvolatile, nonflammable, and low toxicity, while high efficiency, high stability, low cost, and low acid and base consumption are required for the candidate extractant. In recent years, as a green solvent, ionic liquid gained extensive attention and showed tremendous potential to RE green separation. 

Uses Lowers surf, tension between steel and add yielding faster pickling rales protects base metal exc. detergency props. reduces HCI acid consumption Acid Aid X [Crown Tech.)... 

Rapeseed-based biodiesel production has been widely studied in terms of optimization and kinetics of alkali catalyzed transesterihcation reaction (Luque et al., 2011). Recaitly, production of solid base catalysts, such as Ca/Zr mixed oxide catalysts (Liu et al., 2015), CaO-based catalysts or4-sulfophenyl activated carbon-based solid acid catalyst, has been reported with a performance similar to commacial heterogeneous catalyst Amberly st-15 (Malins et al., 2015). Present researches are also focusing on the use of supercritical ethanol and methanol as reagents to avoid drawbacks due to the use of homogeneous catalysts (Farobie and Matsumura, 2015a,b). Technoeconomic and performance studies on the use of supercritical methanol concluded that lower direct costs and environmental impacts are achieved at highest biodiesel yields, where oil consumption per unit of biodiesel... 

Selected Acid-Base Titrimetric Procedures for Organic Functional Groups Based on the Production or Consumption of Acid or Base... 

Historically, the development of the acrylates proceeded slowly they first received serious attention from Otto Rohm. AcryUc acid (propenoic acid) was first prepared by the air oxidation of acrolein in 1843 (1,2). Methyl and ethyl acrylate were prepared in 1873, but were not observed to polymerize at that time (3). In 1880 poly(methyl acrylate) was reported by G. W. A. Kahlbaum, who noted that on dry distillation up to 320°C the polymer did not depolymerize (4). Rohm observed the remarkable properties of acryUc polymers while preparing for his doctoral dissertation in 1901 however, a quarter of a century elapsed before he was able to translate his observations into commercial reaUty. He obtained a U.S. patent on the sulfur vulcanization of acrylates in 1912 (5). Based on the continuing work in Rohm s laboratory, the first limited production of acrylates began in 1927 by the Rohm and Haas Company in Darmstadt, Germany (6). Use of this class of compounds has grown from that time to a total U.S. consumption in 1989 of approximately 400,000 metric tons. Total worldwide consumption is probably twice that. 

---