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Environmental fate & pathways

Adsorption / desorption

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Description of key information

The reliable (all Klimisch 2) information for Kp values in soil is based on laboratory experiments on the distribution of added soluble pentavalent V substances (NH4VO3, Na3VO4 or NaVO3) between the solid and solution phase. All the information available for sediment and suspended matter is based on paired monitoring data of elemental V concentrations in sediment or suspended matter and water. 
A study on Kp values for 464 European soils with varying properties (pH: 3.3-8.0; organic carbon: 0.5-49%; clay: 0.1-70%) was selected as Key study (Janik et al., 2010). Log Kp values for added vanadate range between 1.09 and 4.13 L/kg, with a median of 2.79 L/kg. The median was selected for the chemical safety assessment.
For sediment, 2 reliable Kp values are available (log Kp of 5.2 L/kg for sediments from Hanoi river, Vietnam and a mean log Kp of 4.57 L/kg for freshwater sediments from South Africa). The median of both values was selected for the chemical safety assessment: log Kp=4.89 L/kg.
Reliable data for Kp of suspended matter in 6 water systems are available, with log Kp values ranging from 3.24 to 4.83 L/Kg (median 4.60) for freshwater and a log Kp value of 4.77 for marine water. Because Log Kp values for freshwater and marine water seem to be similar, all data are grouped together and the 5th, 50th and 95th percentiles of the log Kp values according to the best-fitting distribution (log logistic) are 3.82, 4.50 and 5.17 L/kg, respectively. The 50th percentile was selected for the chemical safety assessment.

Key value for chemical safety assessment

Other adsorption coefficients

Type:
log Kp (solids-water in soil)
Value in L/kg:
2.79

Other adsorption coefficients

Type:
log Kp (solids-water in sediment)
Value in L/kg:
4.89

Other adsorption coefficients

Type:
log Kp (solids-water in suspended matter)
Value in L/kg:
4.5

Additional information