A model for predicting sediment-water partition of toxic chemicals in aquatic environments

2002 ◽  
Vol 46 (11-12) ◽  
pp. 437-442 ◽  
Author(s):  
H. Shimazu ◽  
E. Ohnishi ◽  
N. Ozaki ◽  
T. Fukushima ◽  
O. Nakasugi
Keyword(s):  
Organic Matter ◽  
Partition Coefficient ◽  
Water Bodies ◽  
Toxic Chemicals ◽  
Published Data ◽  
Aquatic Environments ◽  
Inorganic Matter ◽  
Water Partition Coefficient ◽  
Japanese Water ◽  
Order Of Magnitude

In order to investigate the characteristics of sediment-water partition of chemicals in aquatic environments using published data, we developed a model for predicting the sediment-water partition coefficient (Kp) as the sum of sorption to sediment organic matter and sorption to sediment inorganic matter. This model is so successful that the differences between Kp (median for a variety of Japanese water bodies) and pre-Kp (predicted Kp) are within one order of magnitude in 24 out of 28 chemicals.

Partitioning of Lindane between sediment, water and the Crustacean Metapenaeus macleayi

1990 ◽  
Vol 41 (3) ◽  
pp. 389 ◽  
Author(s):  
AC Just ◽  
DW Hawker ◽  
DW Connell
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Partition Coefficient ◽  
Rate Constants ◽  
Laboratory Experiments ◽  
Bioconcentration Factor ◽  
Relevant Literature ◽  
Bioaccumulation Factor ◽  
Sorption Site ◽  
Water Partition Coefficient

The partitioning behaviour of lindane between sediment, water and the prawn Metapenaeus macleayi was investigated. The sediment-to-water partition coefficient was determined with sealed glass vials in laboratory experiments and found to be 9.52, or 2164 on an organic carbon basis. This is in agreement with relevant literature data and confirms that the organic matter of the sediment is the primary sorption site in this process. The bioconcentration factor was evaluated from laboratory experiments with prawns in sealed glass jars in which the lindane seawater solution was changed frequently. Under these conditions, effective equilibrium was attained after 24 h. Measured uptake (k1) and clearance (k2) rate constants were smaller than predicted on the basis of existing general relationships between k1, k2 and the octanol/water partition coefficient (Kow) for crustaceans. The bioconcentration factor (KB) was found to be 5.50, or 1273 on a lipid basis, which is also smaller than values estimated from general relationships. The sediment-to-prawn bioaccumulation factor was 0.58, which means that biotic concentrations will be significantly less than those observed in sediments.

scholarly journals Tracer Determinations of Human Red Cell Membrane Permeability to Small Nonelectrolytes

1971 ◽  
Vol 58 (3) ◽  
pp. 259-266 ◽  
Author(s):  
David Savitz ◽  
A. K. Solomon
Keyword(s):  
Cell Membrane ◽  
Partition Coefficient ◽  
Cell Membrane Permeability ◽  
Red Cell ◽  
Red Cell Membrane ◽  
Water Partition Coefficient ◽  
Order Of Magnitude ◽  
Red Cell Membranes ◽  
Human Red Cell Membrane ◽  
Good Agreement

A flow system has been used to determine the permeability of human red cell membranes to four small nonelectrolytes labeled with 14C. The permeability coefficients, ω, in units of mol dyne-1 sec-1 x 1015, are: ethylene glycol, 6; urea, 13; formamide, 22; and methanol, 131. The values for urea and formamide are in good agreement with values obtained by Sha'afi, Gary-Bobo, and Solomon by the minimum method. The unusually high value for ω for methanol is ascribed to its solubility in the red cell membrane since its ether: water partition coefficient is 0.14, higher by more than an order of magnitude than the ether: water partition coefficient for water. The other three solutes are hydrophilic and are characterized by values of ω which behave consistently with those of other hydrophilic amides and ureas. The values of ω for the three hydrophilic solutes measured are also consistent with an equivalent pore radius of about 3.5 A in agreement with previous estimates made on the basis of other types of studies.

Retardation of Toxic Chemicals in a Contaminated Outwash Aquifer

1985 ◽  
Vol 17 (9) ◽  
pp. 57-69 ◽  
Author(s):  
R. J. Patterson ◽  
R. E. Jackson ◽  
B. W. Graham ◽  
D. Chaput ◽  
M. Priddle
Keyword(s):  
Partition Coefficient ◽  
Laboratory Experiments ◽  
Toxic Chemicals ◽  
Disposal Site ◽  
Well Test ◽  
Contaminant Plumes ◽  
Water Partition Coefficient ◽  
Major Process ◽  
Lower Slope ◽  
Range Of Values

Organic chemicals disposed between 1969 and 1980 in a “Special Waste Compound” at the Gloucester Landfill near Ottawa, Canada, are migrating through a confined outwash aquifer. The subsurface distribution of the chemicals down gradient from the disposal site suggests that chromatographic dispersion (i.e. aqueous phase solute transport plus sorption) is the major process controlling migration. Retardation factors calculated on the basis of relative lengths of contaminant plumes agree closely with those determined independently during a purge-well test and indicate a linear relationship with the logarithm of the octanol/water partition coefficient (Kow): The slope, 0.50, of this relationship is at the low end of the range of values reported for other expressions of the same form determined principally on the basis of laboratory experiments. This lower slope may reflect the fact that in aquifers flow is predominantly through the coarser, less organic-rich units. The relatively low range of Kow values (log Kow from −0.27 to 2.83) represented by the contaminants may also be a factor contributing to a smaller slope value.

scholarly journals Effect of Cationic, Non-Ionic and Anionic Surfactants on the Adsorption of Carbofuran on Three Different Types of Indian Soil

2000 ◽  
Vol 18 (4) ◽  
pp. 333-346 ◽  
Author(s):  
R.P. Singh ◽  
J.P. Rawat ◽  
Raj Kumar
Keyword(s):  
Organic Matter ◽  
Partition Coefficient ◽  
Clay Content ◽  
Aqueous Solubility ◽  
Indian Soil ◽  
Molecular Connectivity ◽  
Molecular Connectivity Index ◽  
First Order ◽  
Water Partition Coefficient ◽  
Different Types

The adsorption of carbofuran in aqueous surfactant-free and surfactant (cationic, non-ionic and anionic) solutions of different micellar concentration (½ × CMC, CMC and 2 × CMC) on three different types of Indian soil has been studied using the batch shaking technique. The measured equilibrium adsorption isotherms for the surfactant-free and surfactant/soil/water systems at different critical micellar concentrations were S-shaped and in close agreement to the Freundlich isotherms. Higher adsorption of carbofuran in both systems was observed on silt loam soil followed by loam and sandy soils, and was anticipated by the values obtained for the Freundlich constant, KF, and the partition coefficient, KD. The values of KF and KD obtained also confirmed that the adsorption of carbofuran in aqueous surfactant solutions followed the order cationic > nonionic > anionic at all the CMC values studied. The affinity of carbofuran towards organic matter and the clay content of the soils was evaluated by calculating the Kom and Kc values, when it was found that carbofuran adsorption was better correlated with the clay content than with the organic matter content. The predicted log Kom values were also obtained from the aqueous solubility, 1-octanol/water partition coefficient (Kow), adsorbability index (Al) and first-order molecular connectivity index (1χ) of carbofuran. Use of the aqueous solubility and the 1-octanol/water partition coefficient of carbofuran to predict the adsorption gave values with a considerable error in comparison with those measured experimentally, whereas the use of the absorbability index and first-order molecular connectivity index for carbofuran improved the predictions considerably. The results obtained are interesting in that they afford basic data relating to the possible use of surfactants for solving problems of soil contamination by carbofuran.

Elements for a General Organology

Derrida Today ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 72-94
Author(s):  
Bernard Stiegler
Keyword(s):  
Organic Matter ◽  
Planetary Scale ◽  
General Account ◽  
Inorganic Matter ◽  
History Of

These lectures outline the project of a general organology, which is to say an account of life when it is no longer just biological but technical, or when it involves not just organic matter but organized inorganic matter. This organology is also shown to require a modified Simondonian account of the shift from vital individuation to a three-stranded process of psychic, collective and technical individuation. Furthermore, such an approach involves extending the Derridean reading of Socrates's discussion of writing as a pharmakon, so that it becomes a more general account of the pharmacological character of retention and protention. By going back to Leroi-Gourhan, we can recognize that this also means pursuing the history of retentional modifications unfolding in the course of the history of what, with Lotka, can also be called exosomatization. It is thus a question of how exteriorization can, today, in an epoch when it becomes digital, and in an epoch that produces vast amounts of entropy at the thermodynamic, biological and noetic levels, still possibly produce new forms of interiorization, that is, new forms of thought, care and desire, amounting to so many chances to struggle against the planetary-scale pharmacological crisis with which we are currently afflicted.

Dose-Related Toxicity of Copper and Cadmium in Striped Bass Larvae from the Chesapeake Bay: Field Considerations

1988 ◽  
Vol 20 (6-7) ◽  
pp. 39-48 ◽  
Author(s):  
David A. Wright
Keyword(s):  
Chesapeake Bay ◽  
Striped Bass ◽  
Toxic Metal ◽  
Published Data ◽  
Metal Concentrations ◽  
Frequency Distributions ◽  
Order Of Magnitude ◽  
Toxic Concentrations ◽  
And Control ◽  
Spawning Tributaries

Copper and cadmium monitoring in Chesapeake Bay sediments indicates that metal contamination exists in nursery areas for striped bass (Moronesaxatilis), which has been in serious decline over the last 17 years. Whole water metal concentrations in one spawning river were within an order of magnitude of published acutely toxic concentrations. Larval striped bass were exposed in the laboratory to copper and cadmium concentrations which were acutely toxic over a 96h period (24 and 19 µg L−1, respectively), and to sub-lethal concentrations of these metals over a three week period. Larvae from acutely toxic metal treatments, sub-lethal metal concentrations and control tanks were analyzed for cadmium and copper and the frequency distribution of metal body burdens was compared with field data. The distribution of copper concentrations in laboratory-exposed larvae was completely within the range of field specimens, and there was considerable overlap in cadmium frequency distributions from laboratory and field larvae. These results together with other published data suggest that environmental metal concentrations in some spawning tributaries of the Chesapeake Bay may pose a threat to striped bass, and the suggestion is made that greater efforts should be made to link laboratory and field toxicological data.

scholarly journals QSPR modelling of the octanol/water partition coefficient of organometallic substances by optimal SMILES-based descriptors

2009 ◽  
Vol 7 (4) ◽  
pp. 846-856 ◽  
Author(s):  
Andrey Toropov ◽  
Alla Toropova ◽  
Emilio Benfenati
Keyword(s):  
Partition Coefficient ◽  
Organometallic Compounds ◽  
Applicability Domain ◽  
Training Set ◽  
Input Line ◽  
Test Set ◽  
Water Partition Coefficient ◽  
Definition Of

AbstractUsually, QSPR is not used to model organometallic compounds. We have modeled the octanol/water partition coefficient for organometallic compounds of Na, K, Ca, Cu, Fe, Zn, Ni, As, and Hg by optimal descriptors calculated with simplified molecular input line entry system (SMILES) notations. The best model is characterized by the following statistics: n=54, r2=0.9807, s=0.677, F=2636 (training set); n=26, r2=0.9693, s=0.969, F=759 (test set). Empirical criteria for the definition of the applicability domain for these models are discussed.

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