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.

Review of Bioconcentration, Bioaccumulation and Kow Techniques

1998 ◽  
Vol 33 (2) ◽  
pp. 213-230 ◽  
Author(s):  
B. Kent Burnison
Keyword(s):  
Partition Coefficient ◽  
Direct Measurement ◽  
Organic Contaminants ◽  
Bioconcentration Factor ◽  
Bioaccumulation Factor ◽  
The Past ◽  
Water Partition Coefficient ◽  
Persistent Organic Contaminants ◽  
Bilinear Equations

Abstract Methods have been developed over the past several decades to measure or predict the accumulation of persistent organic contaminants in plants and animals. Most of these methods determine either the bioconcentration factor (BCF), the bioaccumulation factor (BAF), or the n-octanol/water partition coefficient (Kow). Although BCF and BAF are expensive to determine, they do account for metabolism by the target organism whereas the chemically determined Kow does not. Methods recommended by OECD, ASTM and USEPA for the determination of bioconcentration of chemicals are evaluated. Recently finalized USEPA methods are recommended for the determination of BAF and BCF in fish. The slow-stir method is considered the most accurate for a direct measurement of the n-octanol-water partition coefficient (Kow), but computer estimations of Kow can be used when a direct measurement is unavailable. Recent bilinear equations (Howard et al. 1997) have been derived to predict BCF values from Kow.

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.

Removal of Natural Organic Matter (NOM) from Drinking Water Supplies by Ozone-Biofiltration

1999 ◽  
Vol 40 (9) ◽  
pp. 157-163 ◽  
Author(s):  
Raymond M. Hozalski ◽  
Edward J. Bouwer ◽  
Sudha Goel
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Organic Carbon ◽  
Natural Organic Matter ◽  
Laboratory Experiments ◽  
Low Molecular Weight ◽  
Batch Experiments ◽  
Toc Removal ◽  
High Molecular Weight Material ◽  
Effects Of Temperature

Removal of natural organic matter (NOM) in biofilters can be affected by many factors including NOM characteristics, use of pre-ozonation, water temperature, and biofilter backwashing. Laboratory experiments were performed and a biofilter simulation model was developed for the purpose of evaluating the effects of each of these factors on NOM removal in biofilters. Four sources of NOM were used in this study to represent a broad spectrum of NOM types that may be encountered in water treatment. In batch experiments with raw NOM, the removal of organic carbon by biodegradation was inversely proportional to the UV absorbance (254 nm)-to-TOC ratio and directly proportional to the percentage of low molecular weight material (as determined by ultrafiltration). The extent and rate of total organic carbon (TOC) removal typically increased as ozone dose increased, but the effects were highly dependent on NOM characteristics. NOM with a higher percentage of high molecular weight material experienced the greatest enhancement in biodegradability by ozonation. The performance of laboratory-scale continuous-flow biofilters was not significantly affected by periodic backwashing, because backwashing was unable to remove large amounts of biomass from the filter media. Model simulations confirmed our experimental results and the model was used to further evaluate the effects of temperature and backwashing on biofilter performance.

scholarly journals Decomposition of dissolved organic matter released by an isolate of Microcystis aeruginosa and morphological profile of the associated bacterial community

2011 ◽  
Vol 71 (1) ◽  
pp. 57-63 ◽  
Author(s):  
IC. Moreira ◽  
I. Bianchini Jr. ◽  
AAH. Vieira
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Bacterial Community ◽  
Dissolved Organic Matter ◽  
Microcystis Aeruginosa ◽  
Rate Constants ◽  
Bacterial Density ◽  
Bacterial Degradation ◽  
Order Kinetic ◽  
Order Kinetic Model

This study concerns the kinetics of bacterial degradation of two fractions (molecular mass) of dissolved organic matter (DOM) released by Microcystis aeruginosa. Barra Bonita Reservoir (SP, Brazil) conditions were simulated in the laboratory using the associated local bacterial community. The extent of degradation was quantified as the amount of organic carbon transferred from each DOM fraction (< 3 kDa and 3-30 kDa) to bacteria. The variation of bacteria morphotypes associated with the decomposition of each fraction was observed. To find the degradation rate constants (kT), the time profiles of the total, dissolved and particulate organic carbon concentrations were fitted to a first-order kinetic model. These rate constants were higher for the 3-30 kDa fraction than for the lighter fraction. Only in the latter fraction the formation of refractory dissolved organic carbon (DOC R) compounds could be detected and its rate of mass loss was low. The higher bacterial density was reached at 24 and 48 hours for small and higher fractions, respectively. In the first 48 hours of decomposition of both fractions, there was an early predominance of bacillus, succeeded by coccobacillus, vibrios and coccus, and from day 5 to 27, the bacterial density declined and there was greater evenness among the morphotypes. Both fractions of DOM were consumed rapidly, corroborating the hypothesis that DOM is readily available in the environment. This also suggests that the bacterial community in the inocula readily uses the labile part of the DOM, until this community is able to metabolise efficiently the remaining of DOM not degraded in the first moment. Given that M. aeruginosa blooms recur throughout the year in some eutrophic reservoirs, there is a constant supply of the same DOM which could maintain a consortium of bacterial morphotypes adapted to consuming this substrate.

Role of Humified Organic Matter in Herbicide Adsorption

1989 ◽  
Vol 3 (1) ◽  
pp. 190-197 ◽  
Author(s):  
Patrick J. Shea
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Partition Coefficient ◽  
Organic Matter Content ◽  
Clay Content ◽  
Aqueous Solubility ◽  
Structural Diversity ◽  
Polar Compounds ◽  
Matter Content ◽  
Organic Carbon Content

Organic matter is the soil constituent most often associated with herbicide adsorption. Structural diversity makes humified organic material an ideal substrate for the adsorption of many pesticides, but variability in composition and distribution in situ complicates interpretation of its quantitative effect on adsorption. Variability in the adsorption distribution coefficient (KD) of a herbicide among soils often is due to differences in organic matter content and can be reduced by adjusting KDfor soil organic carbon content and computing the organic carbon partition coefficient (Koc). Koccan be estimated from the octanol-water partition coefficient (Kow) of organic compounds, but the correlation weakens as compound polarity increases. Kocalso can be correlated with aqueous solubility if a correction is made for the melting point of compounds that are solids at 25 C. Relative adsorption can be estimated from parachor and molecular connectivity indices; but corrections are needed for polar compounds, and correlations with KDor Kochave been variable. Such predictive methods may be useful for broad classification purposes, but accurate extrapolation generally requires site-specific adsorption measurements. Empirical models which accommodate the multiple regression of organic matter content and other soil properties such as clay content, pH, and cation exchange capacity on herbicide adsorption can increase accuracy, but interpretation may be restricted to a small number of sites.

scholarly journals Direct QSPR: the most efficient way of predicting organic carbon/water partition coefficient (log K OC) for polyhalogenated POPs

2014 ◽  
Vol 25 (3) ◽  
pp. 997-1004 ◽  
Author(s):  
Karolina Jagiello ◽  
Anita Sosnowska ◽  
Sharnek Walker ◽  
Maciej Haranczyk ◽  
Agnieszka Gajewicz ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Partition Coefficient ◽  
Water Partition Coefficient

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.

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