Phenols river models

In water, neither volatilization nor sorption to sediments and suspended particulates is expected to be an important transport mechanism. Using the Henry s Law constant, a half-life of 88 days was calculated for evaporation from a model river 1 m deep with a current of 1 m/second, and with a wind velocity of 3 m/second (Lyman et al. 1982). The biological treatment of waste water containing phenol has shown that less than 1% of phenol is removed by stripping (Kincannon et al. 1983 Petrasek et al. 1983). 

The various chlotophenols were mixed in water purified by the Milli-Q system (Millipore Corp., Bedford, Mass.) or filtered river water, as noted. Samples of the chlorophenols were placed in 250 mL flasks on a gyratory shaker (Model R-2, New Brunswick Scientific, Edison, NJ). The chlorophenol solution was adjusted to pH 6—7 by a 10 mM phosphate buffer. Peroxide and/or HRP were then added to the solution and the flasks were shaken at 175 rpm for 3 hours. Selected samples were centrifuged (Janetzki K24, Englesdorf, Germany) at 12,000 rpm to remove any suspended material. Afterwards, phenols were analyzed as described below. 

In another study, ammonia fixation of N-labeled ammonium hydroxide with Suwannee River fiilvic acid, IHHS peat and leonardite humic acid were examined by solution NMR with the application of INEPT and DEPT pulse sequences.(23) Similar reaction of ammonia with all three samples is reported. Most of the nitrogen incorporated seems to be in the form of indole and pyrrole followed by pyridine, pyrazine, amide and aminohydroquinone nitrogen. The authors also suggest a possible reaction mechanism to explain the formation of the heterocyclic compounds identified in the spectra. They also claimed that these results need to be substantiated through further work with model compounds and experiments with the reaction conditions, i.e., in which phenols will undergo oxidation to quinones when reacted with ammonia. 

In the water quality model developed by Burke and McCleary (20), correlations are established between the levels of various pollutants (phenols, cyanides, and ammonia), and selected environmental parameters (pH, river flow, temperature, microbial biomass). The data required for this analysis were collected over a nine-month period at four monitoring stations along a river. 

In other simulations with phenol (Nendza, Volmer and Klein, 1990), EXAMS was adapted for two river scenarios regarded to be representative for Germany the Rhine was selected to represent the large rivers, and the Leine was chosen to represent the smaller, shorter rivers with lower water volume. Besides features of the particular environmental scenario, various compound-specific data are included in the model ... 

For the example of a risk assessment of phenol exposures in river environments, toxicity estimates (Table 9.3) were obtained for several aquatic species (fish, crustaceae, algae and bacteria). Two criteria are used in choosing the appropriate prediction models ... 

Hollow fiber-based extraction can be used for the determination of freely dissolved phenols or total concentration of phenols in environmental water samples. Liu et al. [199] applied hollow fiber-based supported liquid membrane (SLM) coupled with HPLC to the determination of freely dissolved chlorophenols in water samples. In this equilibrium sampling through membranes, freely dissolved chlorophenols were successfully determined in model solutions of humic acids and at low-ppb levels in river and leachate waters. 

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