Reaction mass of cobalt and copper and iron

Adsorption / desorption

Key value for chemical safety assessment

Other adsorption coefficients

Type:

log Kp (solids-water in soil)

Value in L/kg:

3.47

Other adsorption coefficients

Type:

log Kp (solids-water in suspended matter)

Value in L/kg:

4.59

Other adsorption coefficients

Type:

log Kp (solids-water in sediment)

Value in L/kg:

2.94

Other adsorption coefficients

Type:

log Kp (solids-water in raw sewage sludge)

Value in L/kg:

4.59

Other adsorption coefficients

Type:

log Kp (solids-water in settled sewage sludge)

Value in L/kg:

4.59

Other adsorption coefficients

Type:

log Kp (solids-water in activated sewage sludge)

Value in L/kg:

4.59

Additional information

Five different partitioning coefficients are derived for Cobalt:

1)      Suspended particulate matter (SPM) freshwater Log Kd

2)      Suspended particulate matter (SPM)seawater Log Kd

3)      Sediment freshwater Log Kd

4)      Sediment seawater Log Kd

5)      Soil Log Kd

The partitioning coefficients used for the derivation of the typical values are summarized in the Tables below.

 Table: SPM- Freshwater environment

Location	Log Kd (L/kg)	Remarks	Reference
Czech rivers	4.43	Median Kd	Veselý J (2001)
River Calder   River Nidd   River Swale   River Trent	3.64 4.76 4.28 5.22 4.5 5.68 3.83 4.99	Min value Max value Min value Max value Min value Max value Min value Max value	Lofts (2000)
Swale (upper river) Trent River	4.8 4.3	Mean value Mean value	Tipping (1998)
River Po	2.53	Mean value	Pettine (1994)
Saint Lawrence river	5.7	Mean value	Quèmerais (1996)
Perch lake	7.11 6.73	Mean Kp suspended particle Mean Kp sediment trap	Diamond (1990)
River Po	3.85 5.46 4.68	Min value Max value Average value	Queirazza (1987)
Hudson river	5.49	Average value	Li (1984)
Rio Grande Rio Puerco Rio Salado	3.35 2.55 2.59	Average value Average value Average value	Popp and Laquer (1980)
Huanghe river (yellow river)	5.53 6.29	Min measured Max measured	Zhang (1994)
Sagami river (Japan) Yura river (Japan)	5.9 6.2	Mean value Mean value	Takata (2010)

 

Table: SPM- Seawater

Location	Log Kd (L/kg)	Remarks	Reference
Seatanks at Winfrith	3.66	^57Co after 168h	Leonard (1993)
North Sea	4.12 6.46 4.58 5.38 6.19	Minimum Maximum 10th P Median 90th P	Tappin (1995)
Kara Sea: the Novaya Zemlya Trough (NZT) and the mixing zones of the OB and Yenisey Rivers (RMZ)	4.65 3.00 5.30 4.89 3.90 5.43	Median(NZT) Minimum (NZT) Maximum (NZT) Median (RMZ) Minimum (RMZ) Maximum (RMZ)	Carroll (1999)
Seine estuary	5	Salinity range of 20-30 g/L	Chiffoleau (1994)
New York Bight	4.28	Average value	Li (1984)
Sagami Bay (Japan) Wakasa Bay (Japan)	5.2 5.9	Mean value Mean value	Takata (2010)

 

Table: Sediment -Freshwater

Location	Log Kd (L/kg)	Remarks	Reference
Pinheiros River, Brasil	2.63	Aerobic	Lima (1993)
Tejo river, Portugal	2.9 3.6	2000 mg sediment/L 500 mg sediment/L	Madruga (1992)

 

Table: Sediment – Seawater

Location	Log Kd (L/kg)	Remarks	Reference
Kara Sea: the Novaya Zemlya Trough (NZT) and the mixing zones of the OB and Yenisey Rivers (RMZ)	5.18 4.48 5.48 4.26 3.30 4.60	Median (NZT) Minimum (NZT) Maximum (NZT) Median (RMZ) Minimum (RMZ) Maximum (RMZ)	Carroll (1999)
Kara Sea + Fjords	6.3 4   3.08   6.3	Field (open Kara sea) Experimental (Open Kara sea) Experimental (Abrosimov Fjord) Experimental (Stepovogo Fjord)	Fisher (1999)

 Table: Soil – Water

Log Kd (L/kg)	Remarks	Reference
0.05 1.10 3.47 4.18 4.23	Minimum 10th percentile Median 90th percentile Maximum	Janik (2010) (474 experimental values)

Modeled values should not be taken into account when many measured data are available. As the amount of measured data is high, modeled data were not used for the derivation of the Log Kd values.

Using the collected data that are presented in the Tables above, typical Cobalt log Kd values are derived as the median value of averaged values per river or location (i.e. only one average value per river/location taken into account). A typical range of Kd values is based on the 10^thand 90^thpercentiles of the complete datasets (as presented in the tables above). For freshwater sediment, the minimum and maximum of the dataset was used because less than 5 datapoints are available (metal-specific REACH guidance, R.7.13-2, figure 2).

The 10^th, 50^th(median) and 90^thpercentile of the various log Kd-distributions are compared in the Table below: 

 

	SPM Freshwater	SPM Seawater	SEDIMENTFreshwater	SEDIMENT Seawater	SOIL
10th percentile	2.97	3.78	2.63 (Min)	3.28	1.10
50th percentile	4.59	4.94	2.94	5.15	3.47
90th percentile	6.25	6.05	3.60 (Max)	6.28	4.18

 

Similar median values were obtained for the SPM distributionfunctions in freshwater and marine water (Log Kd of 4.59 – 4.94).The median Kd for sediment-seawater is one order of magnitude higher (Log Kd of 5.15), whereas the median Kd of sediment-freshwater and median Kd soil are more than one order of magnitude lower (Log Kd of 2.94 – 3.47) compared to the median Kd for suspended matter.

The derived mean Kd value for suspended matteris in accordance with the median partition coefficient that was proposed by the US EPA, Office of Solid Waste (1999). Based on literature data (n=20) a median log Kd of 4.7 was derived using a log-normal distribution. The proposed median Kd for soil is about one order of magnitude larger than the value reported by the same US EPA report (log Kd = 2.1, based on 11 data and a log-normal distribution), which may be explained by the larger dataset used in the present report (n = 474).

Values for solids-water in sewage sludge were added for CHESAR calculations and are based on the SPM freshwater.