Quaternary ammonium compounds, C12-14-alkyl(hydroxyethyl)dimethyl, chlorides

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 October - 17 December 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

batch equilibrium method

Media:

other: soil, sediment, sewage sludge

Test material

Test material information

Constituent 1

Reference substance name:

[see concordance under 1.1. of the CSR]

IUPAC Name:

[see concordance under 1.1. of the CSR]

Details on test material:

Unlabelled test substance (NOTOX substance 200547)
- Name of test material (as cited in study report): HYEQS
- Physical state: Solid, white crystals
- Purity: 98.8%
- Lot/batch No.: DEG4052477
- Expiration date of the lot/batch: 1 March 2011
- Stability under storage conditions: Stable
- Storage condition of test material: at room temperature in the dark
14C-labelled test substance (NOTOX substance 198324)
- Name of test material (as cited in study report): [14C]HYEQS
- Physical state: Solid
- Radiochemical purity: Not indicated
- Chemical purity: Not indicated
- Lot/batch No.: CFQ40638 Batch B1
- Expiration date of the lot/batch: 24 September 2010
- Specific activity: 4.29 GBq/mmol (13.8 MBq/mg)
- Locations of the label (if radiolabelling): hydroxyethyl group (2 labels)
- Stability under storage conditions: Not indicated
- Storage condition of test material: In freezer (≤ -15°C) in the dark

Radiolabelling:

yes

Study design

Test temperature:

20 +/- 2°C

Batch equilibrium or other method

Analytical monitoring:

yes

Details on sampling:

Determination of adsorption/desorption equilibrium (kinetics experiment):
- Concentration: 0.5 mg/L
- Sampling interval: 3, 6, 24 and 27 h (adsorption soils and sediment), 2, 3, 23 and 27 h (desorption soils and sediment); 2, 4, 6 and 24 h (adsorption sludges), 2, 4, 6 and 24 h (desorption sludges)
Determination of isotherms:
- Concentrations: 0.01 - 0.05 - 0.2 - 0.5 - 1 mg/L
- Sampling interval: 24 h (adsorption) and 24 h (desorption) for soils, sediments and sludges

Details on matrix:

CRANFIELD 164 SOIL
COLLECTION AND STORAGE
- Geographic location: Farditch Farm, Chelmorton, Buxton, United Kingdom (OS map reference SK 1050269133)
- Storage conditions: refrigerated after receipt; ambient temperature after sieving/air drying
- Storage length: maximum 22 months
- Soil preparation: sieved (2 mm) and air dried
PROPERTIES
- Soil texture
-% sand: 20
-% silt: 52
-% clay: 28
- Horizon: 10-20 cm
- Soil classification system: silty clay loam (USDA)
- pH: 6.0
- Organic carbon (%): 3.7
- CEC (meq/100 g): 22.8
- Water holding capacity (%): 65.7

CRANFIELD 277 SOIL
COLLECTION AND STORAGE
- Geographic location: Posher Farm, Upton, Leamington Spa, Warwickshire, United Kingdom (OS map reference SP 3706562304)
- Storage conditions: Ambient temperature after receipt
- Storage length: maximum 21 months
- Soil preparation: sieved (2 mm) and air dried
PROPERTIES
- Soil texture
- % sand: 19
-% silt: 24
- % clay: 57
- Horizon: 0-20 cm
- Soil classification system: clay (USDA)
- pH: 7.4
- Organic carbon (%): 2.7
- CEC (meq/100 g): 8.3
- Water holding capacity (%): 66.6

CRANFIELD 299 SOIL
COLLECTION AND STORAGE
- Geographic location: Stoke Hill Farm, Erlestoke, Wiltshire, United Kingdom (OS map reference ST 9518952867)
- Storage conditions: Ambient temperature after receipt
- Storage length: maximum 21 months
- Soil preparation: sieved (2 mm) and air dried
PROPERTIES
- Soil texture
- % sand: 28
- % silt: 46
- % clay: 26
- Horizon: 3-20 cm
- Soil classification system: loam (USDA)
- pH: 7.6
- Organic carbon (%): 2.9
- CEC (meq/100 g): 14.9
- Water holding capacity (%): 62.1

SW SEDIMENT
- Location: Schoonrewoerdse Wiel, Leerdam, The Netherlands
- Details on collection: sediment was sampled from the upper layer (0-10 cm) from the middle of the pond (depth 8 m)
- Storage conditions: refrigerated after receipt; ambient temperature after sieving/air drying
- Textural classification (i.e. %sand/silt/clay): 6/59/35
- pH: 8.3
- Organic carbon (%): 11.1
- CEC (meq/100 g): 47.3

ACTIVATED (SECONDARY) SLUDGE (TILBURG)
- Type of sludge: Mix of domestic and industrial waste water
- Source of sludge: Sewage treatment plant RWZI Tilburg-Noord, Tilburg, The Netherlands
- Oxygen status: aerobic
- Details on preparation: The sludge was allowed to settle at ambient temperature. The water layer was separated as much as possible from the precipitated sludge and discarded. The sludge was centrifuged (1700 g, 5 min) and the supernatant was decanted. The sludge was frozen at -20°C and subjected to freeze-drying. After freeze-drying, the sludge was sieved over a 2 mm sieve and dried overnight in an oven at 103°C.
- Storage conditions: ambient temperature
- Textural classification (i.e. %sand/silt/clay): 8/28/64
- pH: 6.3
- Organic carbon (%): 39.0
- CEC (meq/100 g): 129

PRIMARY SLUDGE (AA EN MAAS)
- Type of sludge: Mix of domestic and industrial waste water
- Source of sludge: Sewage treatment plant Waterschap Aa en Maas, 's-Hertogenbosch, The Netherlands
- Treatment system: aerobic and anaerobic
- Details on preparation: The sludge was allowed to settle at ambient temperature. The water layer was separated as much as possible from the precipitated sludge and discarded. The sludge was centrifuged (1700 g, 5 min) and the supernatant was decanted. The sludge was frozen at -20°C and subjected to freeze-drying. After freeze-drying, the sludge was sieved over a 2 mm sieve and dried overnight in an oven at 103°C.
- Storage conditions: ambient temperature
- Textural classification (i.e. %sand/silt/clay): 39/7/54
- pH: 4.5
- Organic carbon (%): 47.1
- CEC (meq/100 g): 147

Details on test conditions:

TEST SYSTEM
- Type, size and further details on reaction vessel: 50 mL polypropylene tubes
- Solution: 0.01 M CaCl2 solution (1.47 g calcium chloride dihydrate/L Milli-Q water)
- Amount of soil/sediment/sludge and water per treatment: 0.45 g soils and sediment or 0.09 g sludges; 45 mL CaCl2 solution
- Soil/sediment-water ratio: 1:100
- Sludge-water ratio: 1:500
- Number of reaction vessels/concentration: 2
- Measuring equipment: LSC
- Are the residues from the adsorption phase used for desorption: yes

Computational methods:

The Freundlich adsorption and desorption isotherm parameters were calculated by fitting the Freundlich isotherm to the data. Optimisations were performed using the program ModelMaker (AP Benson, Wallingford, Oxfordshire, UK).

Results and discussion

Adsorption coefficient

Adsorption coefficient 1

Type:

Koc

Remarks:

of Cranfield 164 Soil (3.7 % OC, 28 % Clay, CEC 22.8 meq/100 g soil)

Value:

12 608

Temp.:

20 °C

% Org. carbon:

3.7

Remarks on result:

other: at lowest measured conc. of 10 µg/L HYEQS

Adsorption coefficient 2

Type:

Koc

Remarks:

of Cranfield 277 Soil (2.7% OC, 57 % Clay, CEC 8.3 meq/100g soil)

Value:

254 926

Temp.:

20 °C

% Org. carbon:

2.7

Remarks on result:

other: at lowest measured conc. of 10 µg/L HYEQS

Adsorption coefficient 3

Type:

Koc

Remarks:

of Cranfield 299 Soil (2.9 % OC, 26 % Clay, CEC 14.9 meq/100 g soil)

Value:

137 362

Temp.:

20 °C

% Org. carbon:

2.9

Remarks on result:

other: at lowest measured conc. of 10 µg/L HYEQS

Adsorption coefficient 4

Type:

Koc

Remarks:

of Sediment SW (11.1 % OC, 35 % Clay, CEC 47.3 meq/100 g sediment)

Value:

41 203

Temp.:

20 °C

% Org. carbon:

11.1

Remarks on result:

other: at lowest measured conc. of 10 µg/L HYEQS

Adsorption coefficient 5

Type:

Koc

Remarks:

of Primary sludge from STP (47.1 % OC, 54 % Clay, CEC 147 meq/100 g sludge)

Value:

4 016

Temp.:

20 °C

% Org. carbon:

47.1

Remarks on result:

other: at lowest measured conc. of 10 µg/L HYEQS

Adsorption coefficient 6

Type:

Koc

Remarks:

of Secondary (activ.) sludge from STP (39% OC, 64 % Clay, CEC 129 meq/100 g sludge)

Value:

3 674

Temp.:

20 °C

% Org. carbon:

39

Remarks on result:

other: at lowest measured conc. of 10 µg/L HYEQS

Results: Batch equilibrium or other method

Adsorption and desorption constants:

See tables below

Recovery of test material:

At the end of the adsorption phase more than 95.1% of the applied activity was recovered; at the end of the desorption phase more than 97.7% of the applied activity was recovered .

Concentration of test substance at end of adsorption equilibration period:

Adsorption equilibrium was reached within 24 hours. The amount of HYEQS adsorbed was 67-98% (data from the kinetics experiment).

Concentration of test substance at end of desorption equilibration period:

Desorption equilibrium was reached after 24 hours. The amount of HYEQS desorbed was 3.7-18% (data from the kinetics experiment).

Any other information on results incl. tables

HYEQS adsorption and desorption isotherms could be described by the Freundlich equation. Freundlich isotherm parameters are summarised in the tables below.

Freundlich adsorption isotherm parameters for HYEQS

Test system	KF^ads (mL/g)	KF,oc^ads (mL/g)	1/n	r^2	data points
Cranfield 164 soil	122	3304	0.78	1.00	10
Cranfield 277 soil	1059	39239	0.76	0.999	10
Cranfield 299 soil	278	9597	0.62	0.998	10
SW sediment	636	5734	0.73	0.992	10
Activated sludge (Tilburg)	1211	3106	0.96	1.00	10
Primary sludge (Aa en Maas)	1681	3568	0.97	0.993	10

 

Freundlich desorption isotherm parameters for HYEQS

Test system	KF^des (mL/g)	KF,oc^des (mL/g)	1/n	r^2	data points
Cranfield 164 soil	218	5902	0.77	0.999	10
Cranfield 277 soil	1756	65055	0.86	0.994	10
Cranfield 299 soil	318	10981	0.58	0.999	10
SW sediment	1172	10560	0.93	0.913	10
Activated sludge (Tilburg)	1679	4305	0.96	1.00	10
Primary sludge (Aa en Maas)	2747	5832	0.92	0.999	10

 

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

HYEQS adsorption and desorption isotherms could be described by the Freundlich equation. KF,ocads values were 3304 mL/g (Cranfield 164 soil), 39239 mL/g (Cranfield 277 soil), 9597 mL/g (Cranfield 299 soil), 5734 mL/g (SW sediment), 3106 mL/g (activated sludge - Tilburg) and 3568 mL/g (primary sludge - Aa en Maas).