Quaternary ammonium compounds, bis(C16-18 and C18-unsatd. alkyl)dimethyl, chlorides

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption, other

Remarks:

adsorption

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

1983

Reliability:

2 (reliable with restrictions)

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1983

Materials and methods

Principles of method if other than guideline:

Batch adsorption test

GLP compliance:

not specified

Type of method:

other: Adsorption was measured using a liquid scintillation counter

Media:

sediment

Test material

Test material information

Constituent 1

Reference substance name:

14C-DODMAC

IUPAC Name:

14C-DODMAC

Constituent 2

Reference substance name:

Dimethyldioctadecylammonium chloride

EC Number:

203-508-2

EC Name:

Dimethyldioctadecylammonium chloride

Cas Number:

107-64-2

Molecular formula:

C38H80N.Cl

IUPAC Name:

N,N-dimethyl-N-octadecyloctadecan-1-aminium chloride

Test material form:

solid

Details on test material:

A commercially available mixture of unlabelled DODMAC had an average alkyl chainlength of ~C17.7. Chemical purity was > 95 %, as determined by TLC and HPLC. All other chemicals used in testing were reagent grade, obtained from commercial sources.

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not relevant

Radiolabelling:

yes

Study design

Test temperature:

No details given

HPLC method

Details on study design: HPLC method:

Not relevant

Batch equilibrium or other method

Analytical monitoring:

yes

Details on sampling:

No details supplied

Details on matrix:

Collected from two rivers (Rapid creek, Rapid City, SD; Ohio River, Cincinnati, OH) at locations 0.5 to 1.0 mile below the discharge of municipal wastewater treatment treatment plants. The sites varied significantly in terms of hydrological/geological characteristics. Rapid creek is a slow-flowing mountain stream (mean discharge ~ 50 ft3/s) with a low wastewater dilution factor (~1:5-1:10), whereas the Ohio River is a rapidly flowing major river (mean discharge ~2000,000 ft3) with high wastewater dilution factor (>1:10,000). Sediment samples were analysed for cation exchange capacity (CEC), pH, particle distribution, organic carbon, and suspended solids levels by standard procedures. They were tested on a dry weight basis. Compartive data for the two river sediments and a standard EPA sediment (EPA 18) are given in Table 1.

Details on test conditions:

Mixtures of test chemical and sediment were placed into 220 ml beakers containing 150-200 ml of 0.01 M KCl buffer. the beakers were agitated on a rotary platform shaker at room temperature to maintain uniform solids suspensions and at various intervals aliquots were removed and centrifuged at 39,000 xg for 30 min to remove particulate matter. The amount of radioactivity in solution, or on the solids after combustion, was then quantitated b

Computational methods:

Csolids

C solids
K2 = ____________
C solution

where: Csolids = ug/g on the solids

Csolution = ug/ml in solution

Equation (1) is a modified form of the Freundlich isotherm

Csolids = KdCsolution l/n

which is generally used to model adsorption processes. the Kd value can be derived from equation 2 when n=1 and can be extrapolated to different sediments by normalising for the organic carbon content of the sediment.

Results and discussion

Partition coefficients

Partition coefficients 1

Phase system:

other: Kd (sediment-water)

Type:

other: Kd (sediment-water)

Value:

12 489 L/kg

Remarks on result:

other: EPA 18 sediment

Partition coefficients 2

Phase system:

other: Kd (sediment-water)

Type:

other: Kd (sediment-water)

Value:

3 833

Remarks on result:

other: Ohio river sediment

Partition coefficients 3

Phase system:

other: Kd (sediment-water)

Type:

other: Kd (sediment-water)

Value:

10 775

Remarks on result:

other: Rapid creek sediment

Results: HPLC method

Details on results (HPLC method):

Not relevant

Results: Batch equilibrium or other method

Adsorption and desorption constants:

No details given

Recovery of test material:

No details given

Concentration of test substance at end of adsorption equilibration period:

No details given

Concentration of test substance at end of desorption equilibration period:

No details given

Transformation products:

not specified

Statistics:

No details given

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

See Excutive summary below

Executive summary:

The sorption of DODMAC was investigated with 3 different sediments resulting in the Kd values of 3833, 10775 and 12489 L/kg.. For the EU Risk Assessment a Kd sediment of 10000 L/kg was assumed for the sediment/water partitioning of DODMAC. When assuming a suspended matter concentration of 15 mg/L in an STP effluent a Kd susp. matter of 16800 L/kg can be calculated from these data. As no measured data for the adsorption to soil is available the Kd sediment was used for Kd soil as well in the EU Risk Assessment (Kd soil 10000 L/kg).