Registration Dossier

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:
OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
batch equilibrium method
Media:
other: soil, sediment, sewage sludge

Test material

Reference
Name:
Unnamed
Type:
Constituent
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 coefficientopen allclose all
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
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
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
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
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
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

KFads

(mL/g)

KF,ocads

(mL/g)

1/n

r2

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

KFdes

(mL/g)

KF,ocdes

(mL/g)

1/n

r2

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).