Removal rate rapid

CO conversion is a function of both temperature and catalyst volume, and increases rapidly beginning at just under 100°C until it reaches a plateau at about 150°C. But, unlike NO catalysts, above 150°C there is Htde benefit to further increasing the temperature (44). Above 150°C, the CO conversion is controUed by the bulk phase gas mass transfer of CO to the honeycomb surface. That is, the catalyst is highly active, and its intrinsic CO removal rate is exceedingly greater than the actual gas transport rate (21). When the activity falls to such an extent that the conversion is no longer controUed by gas mass transfer, a decline of CO conversion occurs, and a suitable regeneration technique is needed (21). 

Structural effects on the rates of deprotonation of ketones have also been studied using veiy strong bases under conditions where complete conversion to the enolate occurs. In solvents such as THF or DME, bases such as lithium di-/-propylamide (LDA) and potassium hexamethyldisilylamide (KHMDS) give solutions of the enolates in relative proportions that reflect the relative rates of removal of the different protons in the carbonyl compound (kinetic control). The least hindered proton is removed most rapidly under these... 

Thus, under the hydrodynamic conditions prevailing at high rotation rates, the one-electron product is removed more rapidly by convection than by the chemical reaction, while at slow rotation speeds the chemical reaction and further electron transfer predominates. The form of the electrode and the hydrodynamic conditions prevailing in the electrolysis solution are therefore parameters which require controlling but which give additional flexibility in the design of syntheses. 

An advantage of the CURE process is the ability to achieve high contaminant removal rates. Also, floe, a by-product of the CURE process, tends to be stable and settle rapidly. Electrocoagulation will not remove metals that do not form precipitates. In addition, electrocoagulation will not remove nonreactive, soluble organic compounds nor desalinate water. 

There are different time scales associated with the various emissions and uptake processes. Two terms that are frequently used are turnover time and response or adjustment) time. The turnover time is defined as the ratio of the mass of the gas in the atmosphere to its total rate of removal from the atmosphere. The response or adjustment time, on the other hand, is the decay time for a compound emitted into the atmosphere as an instantaneous pulse. If the removal can be described as a first-order process, i.e., the rate of removal is proportional to the concentration and the constant of proportionality remains the same, the turnover and the response times are approximately equal. However, this is not the case if the parameter relating the removal rate and the concentration is not constant. They are also not equal if the gas exchanges between several different reservoirs, as is the case for C02. For example, the turnover time for C02 in the atmosphere is about 4 years because of the rapid uptake by the oceans and terrestrial biosphere, but the response time is about 100 years because of the time it takes for C02 in the ocean surface layer to be taken up into the deep ocean. A pulse of C02 emitted into the atmosphere is expected to decay more rapidly over the first decade or so and then more gradually over the next century. 

Figures 5 and 6 show the effect of temperature on the removal of solid C20 (melting point = 37 °C) by C E04. These plots of normalized intensity of the v CH2 band versus time were obtained from two series of experiments, in which the initial layer thickness was varied somewhat. As discussed above, these plots must be regarded as qualitative descriptors of the removal process, due to the optical complexity of the interface. The removal process may involve not only solubilization, but also a surfactant - induced displacement of C q crystallites from the IRE surface, which cannot be treated as a gradual thinning of the C20 layer. Repeated experiments on the effect of temperature on removal rate indicate that if the conditions of layer preparation (hydrocarbon concentration in hexane, speed of withdrawal from the solution) are held constant, then reproducible band intensities of the initial layers are obtained. The shape of the removed plots (Figures 5 and 6) are affected by the initial layer thicknesses. More rapid removal was usually observed for thinner layers of smaller initial Qq band intensity.

Flux measurements to collector surfaces demonstrated that removal rates can be very rapid. In Table I, characteristic times have been calculated for deposition during dense fog. These values were determined from the total solute fluxes, mixing heights, and average pollutant concentrations measured during the individual events. The removal times were calculated to be 6 to 12 h for these periods with the exception of N(V) in non-acidic fogs. Between the occurrences of fog, aerosol deposition was substantially reduced ... 

The conjugate cathodic rate-limiting reaction is O2 reduction to O , reaction (5). Removal is poor over pure Ti02 in O2 or air due to the high overpotential of this reaction. In contrast, the reaction is remarkably rapid over platinized Ti02, because Pt facilitates the reaction (Chenthamarakshan et al., 1999 Lawless et al., 1990 Murruni et al., 2007 Tanaka et al., 1986 Torres and Cervera-March, 1992). In agreement, the concentration of dissolved O2 was found to decrease on illumination (Tanaka et al., 1986) and a dependence of the removal rate with O2 concentration was foimd (Torres and Cervera-March, 1992). Thus, the oxidative route seems to be the preferred photocatalytic pathway in the absence of electron donors. 

Junge (128) estimated that tropospheric aerosols had a lifetime of approximately 10 days, although the rate of removal decreased rapidly with increasing altitude. On the basis of the distribution of fission products,... 

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