Naphthalene Concentrations

AIkyl-Ai,A/-diaLkyl-l-naphthalenecarboxamides are useful herbicides (86) and the 2,2-dimeth5lhydra2ide of 1-naphthalenecarboxyhc acid has been patented as a plant growth regulator (87). 2-Propynyl-2-naphthalenecarboxylate [53548-27-9] and similar esters are insecticides (88). 1-Naphthaleneacetic acid, the plant growth regulator, has been prepared from naphthalene, concentrated HCl, and paraformaldehyde without isolation of intermediate 1-chloromethylnaphthalene or l-naphthaleneacetonitnle (89). 

Dionisi HM, CS Chewning, KH Morgan, E-M Menn, JP Easter, GS Sayler (2004) Abundance of dioxygenase genes similar to Ralstonia sp. strain U2 nagAc is correlated with naphthalene concentrations in coal tar-contaminated freshwater sediments. Appl Environ Microbiol 70 3988-3995. 

For the case where the inlet naphthalene concentration is below the explosion limit and where one is successful in producing phthalic anhydride in commercial yields, the mole fraction oxygen in the reactant gases remains relatively constant. This point is readily seen by the construction of a mole table for a feed containing 0.75% naphthalene, of which 80% reacts to give phthalic anhydride and the remainder goes to C02. 

Now the bulk fluid naphthalene concentration at the reactor inlet is given by... 

Equation 12.3.149 relates the cnanges in phthalic anhydride and naphthalene concentrations in the gas phase... 

Thomas and Delfino (1991) equilibrated contaminant-free groundwater collected from Gainesville, FL with individual fractions of three individual petroleum products at 24-25 °C for 24 h. The aqueous phase was analyzed for organic compounds via U.S. EPA approved test method 625. Average naphthalene concentrations reported in water-soluble fractions unleaded gasoline, kerosene, and diesel fuel were 989, 644, and 167 ug/L. 

Therefore, one-electron oxidation of naphthalene by NO+ is the rate-determining stage at low naphthalene concentrations (= means eqnilibrinm of this oxidation). At high naphthalene concentrations, the rate of the process no longer depends on the rate of accnmnlation of cation-radical species. In this case, the rate depends on recombination of the species with N02 radical. The anthors point ont that for many of the more reactive aromatic componnds, reaction paths involving electron transfer in nitration will become more important as the concentration of the aromatic componnd is increased, irrespective of the concentration of the species accepting the electron (Leis et al. 1988). 

Fig. 8.22 Fraction of naphthalene concentration due to colloidal entrainment at (a) G = 5 and (b) = 20 s , for naphthalene and naphthalene compounds containing 1,2, or 3 C as side chains, where is the mean shear rate. Reprinted with permission from Sterhng Jr MC, Bonner JS, Page CA, Ernest ANS, Auteniieth RL (2003) Partitioning of crude oil polycyclic aromatic hydrocarbons in aquatic systems. Environ Sci Technol 37 4429 434. Copyright 2003 American Chemical Society...

For example, biotransformation of naphthalene in an operating actiyated sludge treatment system (after correction for abiotic processes) was modelled a priori by an elementary first-order (in naphthalene concentration) rate equation (24). The complex actiyated sludge system was perturbed by induction of sinusoidal naphthalene feed concentrations for eight sinusoidal frequencies while the naphthalene in the reactor offgas was measured eyery ten minutes. Abiotic fates (stripping, and sorption) were accounted for and... 

Naphthalene concentrations averaged 6000 ng m 3 and ranged from 0.0 to 22,600 ng m 3, consistent with the measurements of Arey et al. (1989a) discussed earlier (see Table 10.10). 

Evidence for photoassociation in the triplet manifold is at present inconclusive. Although Hoytink et al.20 have reported excimer phosphorescence from cooled ethanolic solutions of phenanthrene and naphthalene, concentration and temperature-dependent studies of the emission characteristics must be extended in order to distinguish photoassociation of the triplet state from intersystem crossing of the singlet excimer and possible triple-triplet annihilation. Certainly the decay constant of the molecular triplet state in fluid media is relatively insensitive to solute concentration21 although this... 

There is a great similarity in the course of the naphthalene metalation by Li at -80°C on one hand and by at RT on the other hand. The titration of the carbanions formed (19) proves the presence of two anions per naphthalene only at naphthalene concentrations lower than 0.03 mol.l- for at RT (Table I) and... 

Time Since Beginning (hours) Chloride Concentration (mg L"1) Time Since Beginning (hours) Naphthalene Concentration (nmol L 1)... 

The second experiment is conducted with naphthalene. At t = 0, the concentration of naphthalene is set to a constant value of Cin = 1 pmol L 1 and the naphthalene concentration measured in the outlet as a function of time (Table 25.3), Calculate the relative dissolved fraction/and the relative organic content of the column material. Use ps = 2.5 g cm-3 and the parameters determined for chloride. 

Gevao, B., T. Hamer, and K. Jones, Sedimentary record of polychlorinated naphthalene concentrations and deposition fluxes in a dated Lake Core , Environ. Sci. Technol., 34,1, 33-38 (2000). 

The relative adsorption constants for hydrogen, naphthalene, and diben-zothiophene have been estimated by determining how the rate constants, as described in Scheme 1, change as a function of the naphthalene concentration in HDS reactions of dibenzothiophene with NiMo/Al203 catalyst at 320°C and 2.5-MPa hydrogen pressure (21, 133, 134). The original data were used to determine the rate constants as described in Section IV, and the LHHW parameters were then estimated. The values obtained in this way are presented in Table XIX. These values should be considered only as estimates as data were limited, but the trends are believed to be valid. 

The changes in the various rate constants with increasing naphthalene concentration are in general agreement with the more accurate data shown in Table XVIII (compare rate constants with and without 10% naphthalene). However, it appears that the direct extraction of sulfur from dibenzothiophene is less susceptible to inhibition than that of 4,6-DMDBT but that... 

Changes in Relative Pseudo-First-Order Constants for HDS of Dibenzothiophene with Increasing Naphthalene Concentrations (NiMo/Al203, 32(f C, 2.5 MPa H2) (21, 41a, 133)... 

Jia et al. (2005) undertook measurements in 30-50 homes in each of 3 cities in Michigan, USA using a tube type sampler that was thermally desorbed and an exposure period of 3-4 days. 49 compounds were identified indoors and indoor/ outdoor ratios ranged from 1 to 82. Significantly higher benzene, toluene and naphthalene concentrations occurred in homes with attached garages and D-limonene was higher in homes with smokers. Concentrations in air reported in one city are summarized in Table 3.2. 

Detailed experimental procedures have been previously reported (Ko, 1998 Ko et al., 1998a,b) therefore, they are only briefly described here. Phenanthrene (Aldrich, 99.5+%), naphthalene (Aldrich, 99+%), SDS (Sigma, 99.5+%), and Tween 80 (Aldrich, no purity reported) were used as received selected physicochemical properties for these compounds are shown in Table 1. Kaolinite, a nonswelling 1 1 layer phyllosilicate clay and common constituent of many subsurface environments, was used as received from Sigma. Solution pH and ionic strength were adjusted as necessary with 0.5 M HC1 and/or 0.5 M NaOH and NaCl, respectively. Aqueous phenanthrene and naphthalene concentrations were quantified by fluorescence (PTI, Inc.) at the excitation/emission wavelengths of 250/364 and 278/322 nm, respectively. A total organic carbon (TOC) analyzer (Shimadzu Model 5050) was used to determine aqueous SDS concentrations and Tween 80 concentrations were determined by UV absorbance at 234 nm. 

From experiments using fixed HOC concentrations (Ct) and varying surfactant concentrations. Values are 1 SD. Ionic Strength = 0.1 M NaCl and pH 4.0 or 4.6 (K ). b Determined by nonlinear regression of eq 1 except as noted.c N, number of data points. d Determined by nonlinear regression of eq 2.c nd, not determined.f Obtained by linear regression of solubility enhancement data. 8 Naphthalene concentration was 78 pM. 

All the rate parameters for the above processes are known and the yield of N as a function of naphthalene concentration can be calculated (25). The yield of naphthalene triplets, Y, is given by... 

Figure 2b. Yield of solute triplets in p-xylene. Naphthalene 30 C ( ) napthalene 100 C ( o ) pyrene ( ) calculated for naphthalene ( ). Concentration units are M/liter. In these calculations (J), is taken as 0.56, while is 0.8 for naphthalene, and ) 2 taken as 3 x 10 M sec". ...

Figure 3. Yield of naphthalene triplet (N ) in the laser photolysis of naphthalene in toluene as a function of naphthalene concentration [N] in moles/L . A represents calculated yield as a function of naphthalene concentration, at [N] = 1.2 mol dm with various concentrations of nitro-methane. Concentrations in moles/L.

The post-expansion temperature (in contrast to the pre-expansion temperature), was found to be Important both at high and low Naphthalene concentrations. Crystallizer temperatures from 8 C to -8 C resulted in the production of Naphthalene crystals with similar size distributions that ranged... 

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