Aqueous solutions of organic

While incineration is the preferred method of disposal for wastes containing high concentrations of organics, it becomes expensive for aqueous wastes with low concentrations of organics because auxiliary fuel is required, making the treatment expensive. Weak aqueous solutions of organics are better treated by wet oxidation (see Sec. 11.5). 

We have considered the surface tension behavior of several types of systems, and now it is desirable to discuss in slightly more detail the very important case of aqueous mixtures. If the surface tensions of the separate pure liquids differ appreciably, as in the case of alcohol-water mixtures, then the addition of small amounts of the second component generally results in a marked decrease in surface tension from that of the pure water. The case of ethanol and water is shown in Fig. III-9c. As seen in Section III-5, this effect may be accounted for in terms of selective adsorption of the alcohol at the interface. Dilute aqueous solutions of organic substances can be treated with a semiempirical equation attributed to von Szyszkowski [89,90]... 

A complete set of intermolecular potential functions has been developed for use in computer simulations of proteins in their native environment. Parameters have been reported for 25 peptide residues as well as the common neutral and charged terminal groups. The potential functions have the simple Coulomb plus Lennard-Jones form and are compatible with the widely used models for water, TIP4P, TIP3P and SPC. The parameters were obtained and tested primarily in conjunction with Monte Carlo statistical mechanics simulations of 36 pure organic liquids and numerous aqueous solutions of organic ions representative of subunits in the side chains and backbones of proteins... 

Freeze concentration has been used for the concentration of aqueous solutions of organic volatiles and substances that are heat labile using an apparatus similar to that shown in Figure 8.4(B) (24,55,56). For successful results, the contact layers... 

Bennett PC, Melcer ME, Siegel DI, Hassett JP (1988) The dissolution of quartz in dilute aqueous solutions of organic acids at 25°C. Geochim. Cosmochim. Acta 52 1521-1530 Barnhisel RL, Bertsch PM (1989) Chlorites and hydroxy-interlayered vermiculite and smectite. 

Aqueous solutions of organic acids such as formic, acetic, and oxalic, decompose mercury fulminate, forming the corresponding mercuric salts. On the other hand, the action of dilute inorganic acids involves decomposition with formation of C02. 

Two general classes of methods can be functionally defined for preparing concentrates of organic substances. Concentration methods involve the removal of water (e.g., lyophilization, freeze concentration, vacuum distillation, reverse osmosis [RO], and ultrafiltration) and result in a more highly concentrated aqueous solution of organic contaminants. Isolation methods are those methods in which the organic substances are physically removed from the aqueous solution, for example, adsorption onto a solid substrate followed by desorption (I). 

A number of aqueous solutions of organic and inorganic chemicals are purified commercially. Dissolved salts, acids, bases, and color bodies arc removed by ion-excliangc resins. 

Standard emf Values for the Cell H2/HCl/AgCl, Ag in Various Aqueous Solutions of Organic Solvents at Various Temperatures Temperature Dependence of the Standard Potential of the Silver Chloride Electrode Standard Electrode Potentials of Electrodes of the First Kind Standard Electrode Potentials of Electrodes of the Second Kind Polarographic Half-Wave Potentials (E1/2) of Inorganic Cations Polarographic E1/2 Ranges (in V vs. SCE) for the Reduction of Benzene Derivatives Vapor Pressure of Mercury... 

STANDARD emf VALUES FOR THE CELL H HCl/AgCI, Ag IN VARIOUS AQUEOUS SOLUTIONS OF ORGANIC SOLVENTS AT VARIOUS TEMPERATURES... 

Previous work in the area of high-pressure phase equilibrium of aqueous solutions of organic compounds with supercritical fluids... 

The introduction of the more sensitive hydrogen flame ionisation detector has made possible the analysis of dilute aqueous solutions of organic acids by gas-liquid chromatography. Problems, such as ghosting at high acid concentrations and an excessive tailing effect of the water in dilute solutions, masking the components, have been reported for aqueous solutions [573],... 

SOLUBILITY OF PICRIC ACID IN AQUEOUS SOLUTIONS OF ORGANIC SOLVENTS... 

The system dependent constant C = 0.277 for water and aqueous solutions of glycerol and glycol C = 0.364 for aqueous solutions of organic electrolytes. It would be highly interesting if future research provided a general relationship for C for organic liquids. 

Fig. 1.1 Schematic representation of a hypothetical fuel cell for the mineralization of organic pollutants ASOP aqueous solution of organic pollutants...

Berlin, A. (1986). Kinetics of radical-chain decomposition of persulfate in aqueous solutions of organic compounds. Kinetic Catal. 27,34-39. 

When aqueous solutions of organic acids are boiled with the dioxide, reduction takes place, metallic platinum being deposited, and the acids oxidised. Hydrogen peroxide solution slowly reduces the dioxide. 

Organosolv. Organosolv lignins are obtained as relatively low-molecular-weight entities by treatment of plant tissue with aqueous solutions of organic solvents, normally containing trace amounts of mineral acids (44) Solvents include ethanol, methanol, butanol, acetic acid, ethyl acetate, phenol, etc. To date, this approach has not been commercialized due to the quantities of organic solvents consumed and the low quality of the pulp fiber obtained. 

For the liquid vapor interface, the surface tension is easUy measured as a function of the concentration as shown in Figure 9.10. The preceding equation can he used to determine the surface excess concentration of surfactant as a function of the sur ctant concentration if the sur ce tension of the solution as a fimction of surfactant concentration is known. For dilute aqueous solutions of organic substrates, the semi-empirical equation for the surface tension, y, of a solution of concentration C2,... 

Values of dg usually vary between 2 and 6 mm. For water and electrolyte solutions Deckwer et al. (JJ,) recommend a value of dg = 2.9 mm which was obtained from a lot of data in various bubble columns. For jet spargers in aqueous solutions of organic substances lower values of dg (1 mm or even less) are also found. Correlations for dg and the interfacial area are reported by... 

Larcbet C, Bmn JP, Bulvestre G, and Auclair B. Sorption and pervaporation of dilute aqueous solutions of organic compounds through polymer membranes. J Membr Sci 1985 25 55-100. 

The aqueous solutions have received attention for more than a century because they are of industrial, environmental and scientific importance. One of the features of the aqueous solutions of organic substances is their microheterogeneity, reflected in the fact that the local concentration differs from the bulk concentration. The microheterogeneities in solutions can be characterized by the following nanometer-level parameters (1) the correlation volume, i.e. the volume in which the concentration differs from the average concentration, (2) the excess (or deficit) number of molecules in the correlation volume compared to the number of molecules when they are randomly distributed, and (3) the inter molecular interactions between the molecules in the above volume. 

Oolman and Blanch [410] point out, that in the coalescence process in aqueous solutions of organic substances, which have a vapor pressure, supply from the solute from the gas bubble in the film surface had to be taken into consideration. They proposed a very complicated formula for this, whose solution has to date foundered on the non-availability of numerical values. 

Many pharmaceutical drugs are in the form of salts, with relatively high solublity in water and very low solubility in organic solvents. Thus, the application of the antisovent process to aqueous solutions of organic salts... 

Oxidation of aqueous solutions of organics (0.5wt%, or 5g 1 ) were performed in a 250 ml Hastelloy C22 autoclave, connected to an air reserve and equipped with a magnetically driven turbine. The reactor was loaded with 150 ml of solution and 1 g of catalyst. After flushing with argon, the temperature of the mixture was raised to the reaction temperature under stirring. Air was then admitted until the preset pressure was attained and the reaction was started by adjusting the stirrer to 1800 rpm, which defined t = 0. Typical operating conditions were 190°C and 5 MPa total pressure. The stirrer speed was maintained at 1800 rpm to minimize mass transfer limitation. The total run time for each experiment was approximately 6 h. 

---