Registration Dossier
Registration Dossier
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EC number: 940-884-3 | CAS number: -
Adsorption / desorption
Administrative data
Link to relevant study record(s)
- Endpoint:
- adsorption / desorption, other
- Remarks:
- desorption
- Type of information:
- read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- key study
- Justification for type of information:
- The available identification data for the Target and the Source substance support the read-across hypothesis. Adequate, reliable and available scientific information indicate that the Target and Source substance have, or are very likely to have, similar (eco)toxicological properties. There are no indications that constituents other than those identified for the substances or impurities may influence the validity of the read-across. There is no evidence that additional toxicological mechanisms, other than those identified in the read-across hypothesis, may be acting or have an adverse effect on the validity of the read-across.
- Reason / purpose for cross-reference:
- read-across source
- Key result
- Type:
- Kd
- Value:
- > 20 L/kg
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: As in slag and basalt
- Key result
- Type:
- Kd
- Value:
- > 70 L/kg
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Cd in slag, >20 in basalt
- Key result
- Type:
- Kd
- Value:
- 800 000 L/kg
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Cr in slag, > 10000 in basalt
- Key result
- Type:
- Kd
- Value:
- > 9 400 L/kg
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Cu in slag, > 6000 in basalt
- Key result
- Type:
- Kd
- Value:
- > 700 L/kg
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Ni in slag, > 4000 in basalt
- Key result
- Type:
- Kd
- Value:
- > 760 L/kg
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Pb in slag, > 130 in basalt
- Key result
- Type:
- Kd
- Value:
- 40 000 L/kg
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Zn in slag, > 6600 in basalt
- Validity criteria fulfilled:
- not applicable
- Remarks:
- recalculation of existing data
- Conclusions:
- The reavaluation of existing data showed that trace elements are tightly bound into slags with high kd values for Ni (> 700 L/kg), Cu (> 9400 L/kg), Zn (> 40000 L/kg) and Cr (> 800000 L/kg). Due to high limits of determination/detection, no estimate could be made for other trace elements.
- Executive summary:
To determine the kdvalues of trace elements of toxicological relevance for REACH Registration, existing concentration data of theslags ABS, BOS, and EAF C, existing concentration data of trace elements in solid slags and natural rocks were compared with their respective concentrations in leachates of slags and natural rocks.
The kdvalues of Hg and Tl could not be determined, because no data had been measured in leachates. The Kdvalues of As and Cd are low (e.g. >20 L/Kg) because these elements (and Hg and Tl) are not present in slags and basalt at relevant levels. The same is most likely correct for Pb. For Ni (>700, >4000 L/kg), Cu (> 9400, > 6000 L/kg), Zn (> 40000, >6600 L/kg) and Cr (> 800000, > 10000 L/kg) high Kdvalues have been obtained, suggesting a very tight binding of these elements into slag and basalt, respectively.
Kd values of EAF C and basalt with the data used for calculation
Parameter
EAF C (mg/kg)*
Basalt (mg/kg)**
Leachates
Kd slags
Kd basalt
As
2
2
< 0.1
>20
> 20
Cd
0.7
0.2
< 0.01
> 70
>20
Cr
approx. 8000
approx. 100
< 0.01
> 800000
>10000
Cu
94
approx. 60
< 0.01
> 9400
> 6000
Hg
<0.2
0.08
not determined
No data
No data
Ni
14
approx. 80
< 0.02
> 700
> 4000
Pb
76
13
< 0.1
> 760
> 130
Tl
< 0.5
not determined
No data
No data
Zn
390
approx. 70
slags = < 0.007
basalt = < 0.011
> 40000
7000
BOS and EAF C: 8 – 11 mm. No data on grain size of ABS.
*Hygiene-Institut des Ruhrgebiets (2001) Pruefbericht A 5006c D/01/C, Gelsenkirchen, on behalf of the FEhS
**Bavarian Landesamt fuer Umweltschutz (LfU), Verwendung von MV-Rostschlacke in Bauvorhaben, 2002.
- Endpoint:
- adsorption / desorption
- Remarks:
- adsorption/desorption
- Type of information:
- other: literature review
- Adequacy of study:
- weight of evidence
- Study period:
- 2000
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Study well documented. Study meets generally accepted scientific principles. Study acceptable for assessment
- Principles of method if other than guideline:
- Literature review on soil−liquid partitioning coefficients (Kd) of several trace elements to predict elemental mobility and bioavailability. Multiple linear regression analysis accounting for pH of the soil solution, the content of metals and organic matter of the soil (SOM). Development of simple model for trace element solubility
- GLP compliance:
- no
- Type of method:
- other: Data compilation
- Media:
- soil
- Radiolabelling:
- no
- Type:
- Kd
- Value:
- 13 119
- Remarks on result:
- other: As soil
- Type:
- Kd
- Value:
- 3 434
- Remarks on result:
- other: Ba soil
- Type:
- Kd
- Value:
- 2 869
- Remarks on result:
- other: Cd soil
- Type:
- Kd
- Value:
- 14 290
- Remarks on result:
- other: Cr soil
- Type:
- Kd
- Value:
- 4 799
- Remarks on result:
- other: Cu soil
- Type:
- Kd
- Value:
- 8 946
- Remarks on result:
- other: Hg soil
- Type:
- Kd
- Value:
- 16 761
- Remarks on result:
- other: Ni soil
- Type:
- Kd
- Value:
- 171 214
- Remarks on result:
- other: Pb soil
- Type:
- Kd
- Value:
- 43 937
- Remarks on result:
- other: Se soil
- Type:
- Kd
- Value:
- 11 615
- Remarks on result:
- other: Zn soil
- Details on results (Batch equilibrium method):
- Compilation of results of approximately 70 studies
Element Arithmetic means of Kd values (L/kg)
As 13119
B 160
Ba 3434
Cd 2869
Cr 14920
Cu 4799
Hg 8946
Mo 36
Ni 16761
Pb 171214
Se 43937
Sr 137
Zn 11615
(Details see IUCLID, 3 tables in "Any other information on results incl. tables")
Temperature and organic carbon of soil not known - Validity criteria fulfilled:
- yes
- Conclusions:
- The presence of soil will further decrease the already very low trace element levels in leachates of slag. Kd of soils is influenced most strongly by
pH, cation-exchange capacity (CEC, for cations), and by the content of amorphous iron oxides and aluminum oxides.
Element Arithmetic Means of Kd values (L/kg)
As 13119
B 160
Ba 3434
Cd 2869
Cr 14920
Cu 4799
Hg 8946
Mo 36
Ni 16761
Pb 171214
Se 43937
Sr 137
Zn 11615 - Executive summary:
A literature review was done on soil−liquid partitioning coefficients (Kd) of several trace elements of toxicological relevance. Although the reported values scattered, mobility and bioavailability of the elements could be predicted. The kd values especially for the metals cadmium, copper, lead, nickel, and zinc exhibited a relationships to variations in the pH of the soil solution, the content of metals and organic matter of the soil (SOM). Multiple linear regressions showed highest correlations to linear regression with pH or with pH and log of one of the other parameters. Solubility of trace metals was interpreted as competitive adsorption of metal cations and hydrogen ions.
- Endpoint:
- adsorption / desorption
- Remarks:
- desorption
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- 2000
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: Guideline study using national guideline. Study meets generally accepted scientific principles. Study acceptable for assessment
- Reason / purpose for cross-reference:
- reference to same study
- Principles of method if other than guideline:
- The Kd values of trace element were calculated as the ratio of the detected concentrations in slags versus the respective leaching data of these slags. If a trace element was only detectable in the solid slag but not in the leachate, the leachate concentration was assumed as being half of the detection limit. The specific Kd values of the trace elements for each slag were calculated from the arithmetic means of these values.
- GLP compliance:
- not specified
- Type of method:
- other: ASTM
- Media:
- soil
- Specific details on test material used for the study:
- Details on properties of test surrogate or analogue material (migrated information):
not applicable - Radiolabelling:
- no
- Test temperature:
- study performed at room temperature
- Details on study design: HPLC method:
- Kd calculated
- Analytical monitoring:
- yes
- Details on sampling:
- Mixed samples compiled from several slag producers (study sponsors)
- Details on matrix:
- slags are similar to natural material like granite with regard to their chemical composition (in general, slags contain far less silicate), physico-chemical properties, toxicity and ecotoxicity. The faster the slag melt is cooled, the higher is the ratio of glass phase to crystalline phase
- Details on test conditions:
- The TCLP (Toxicity Characteristic Leaching Procedure) of the US EPA (United States Environmental Protection Agency) was originally designed to determine the transfer of organic and inorganic pollutants from wastes into the environment. The TCLP analysis simulates landfill conditions in regard to leaching by rain and groundwater. Water which percolates through the solid slag layer will take up trace elements. The TCLP simulates extended leaching periods in the ground. It identifies which trace elements in the leachate exceed standards set by the US EPA and thereby may pose public and environmental health risks.
The TCLP is a leaching procedure which determines the mobility of trace elements under acidic and basic conditions. The TCLP applied on slags includes a determination of the pH-value of the slag leachate, followed by leaching with acetic acid solution at a 1:20 mixture of slag to solvent for 18 h under shaking (tumbling).
Maximum concentration of contaminants for Toxicity Characteristic (the D List of the EPA)
EPA
Hazardous
Waste code Contaminant Regulated Level (mg/L or ppm)
D004 Arsenic 5.0
D005 Barium 100.0
D018 Benzene 0.5
D006 Cadmium 1.0
D019 Carbon Tetrachloride 0.5
D020 Chlordane 0.03
D021 Chlorobenzene 100.0
D022 Chloroform 6.0
D007 Chromium 5.0
D023 o-Cresol 200.0
D024 m-Cresol 200.0
D025 p-Cresol 200.0
D026 Cresol 200.0
D016 2,4-D 10.0
D027 1,4-Dichlorobenzene 7.5
D028 1,2-Dichloroethane 0.5
D029 1,1-Dichloroethylene 0.7
D030 2,4-Dinitrotoluene 0.13
D012 Endrin 0.02
D031 Heptachlor 0.008
D032 Hexachlorobenzene 0.13
D033 Hexachlorobutadiene 0.5
D034 Hexachloroethane 3.0
D008 Lead 5.0
D013 Lindane 0.4
D009 Mercury 0.2
D014 Methoxychlor 10.0
D035 Methyl ethyl ketone 200.0
D036 Nitrobenzene 2.0
D037 Pentachlorophenol 100.0
D038 Pyridine 5.0
D010 Selenium 1.0
D011 Silver 5.0
D039 Tetrachloroethylene 0.7
D015 Toxaphene 0.5
D040 Trichloroethylene 0.5
D041 2,4, 5-Trichlorophenol 400.0
D042 2,4,6-Trichlorophenol 2.0
D017 2,4,5-TP (Silvex) 1.0
D043 Vinyl Chloride 0.2
EPA Publication SW-846 Test Methods for Evaluating Solid Waste, Physical/Chemical Methods, EPA Publication SW-846 [Third Edition (November, 1986), as amended by Updates I (July, 1992), II (September, 1994), IIA (August, 1993), and IIB (January, 1995)] (document number 955-001-00000-1), U.S. Government Printing Office, Washington, DC. - Computational methods:
- Calculation of Kd values from concentrations of trace elements in solid slags and their leachates
Used data:
Arithmetic mean of the concentrations of the trace elements in solid slag (mg/kg)
Arithmetic mean as determined with the ASTM method (mg/L)
Result is the arithmetic mean of the Kd value (L/kg) - Type:
- Kd
- Value:
- 20 835
- % Org. carbon:
- 0
- Remarks on result:
- other: Al
- Type:
- Kd
- Value:
- 1 686
- % Org. carbon:
- 0
- Remarks on result:
- other: Ba
- Type:
- Kd
- Value:
- 78 292
- % Org. carbon:
- 0
- Remarks on result:
- other: Cr
- Type:
- Kd
- Value:
- 7 967
- % Org. carbon:
- 0
- Remarks on result:
- other: Cu
- Type:
- Kd
- Value:
- 1 297 600
- % Org. carbon:
- 0
- Remarks on result:
- other: Fe
- Type:
- Kd
- Value:
- 7 112 857
- % Org. carbon:
- 0
- Remarks on result:
- other: Mn
- Type:
- Kd
- Value:
- 1 320
- % Org. carbon:
- 0
- Remarks on result:
- other: Mo
- Type:
- Kd
- Value:
- 20 667
- % Org. carbon:
- 0
- Remarks on result:
- other: Pb
- Type:
- Kd
- Value:
- 1 015
- % Org. carbon:
- 0
- Remarks on result:
- other: Se
- Type:
- Kd
- Value:
- 11 753
- % Org. carbon:
- 0
- Remarks on result:
- other: V
- Details on results (HPLC method):
- Kd measured by analysis of solid slag and its leachate
- Adsorption and desorption constants:
- see Tables below
- Recovery of test material:
- see Tables below
- Concentration of test substance at end of adsorption equilibration period:
- not applicable
- Concentration of test substance at end of desorption equilibration period:
- as reported in the Tables below
- Transformation products:
- no
- Details on results (Batch equilibrium method):
- The calculated Kd values are higher than 1000 L/kg with few exceptions due to calculation procedure using half the detection limit value as an estimate for concentration in leachates. These calculated results comprise arsenic and tin in blast furnace slag (Kd = 300 and 500 L/kg, for arsenic and tin, respectively).
The Kd values of different slags were similar. Their differences between the slags did no exceed one order of magnitude. - Statistics:
- see Tables below
- Validity criteria fulfilled:
- yes
- Remarks:
- calculation based on scientific principles
- Conclusions:
- The calculated Kd values of trace elements occurring in slag are high (mostly >1000 L/kg).
The Kd values of different slags were similar. Their differences between the slags did no exceed one order of magnitude.
The high Kd values suggest that the trace elements are very tightly bound into the matrix. Leaching is extremely low and transport in soil will be very slow. - Executive summary:
Soil-to-water partition coefficients Kd of individual trace elements occurring in slag were calculated from their concentration in the solid slag, divided by their concentrations in leachate.
The calculated Kd values are higher than 1000 L/kg with few exceptions due to calculation procedure using half the limit of detection as an estimate for concentration in leachates. These calculated results comprise arsenic and tin in blast furnace slag (Kd= 300 and 500 L/kg, for arsenic and tin, respectively).
The Kd values of different slags were similar. Their differences between the slags did not exceed one order of magnitude.
The high Kd values suggest that the trace elements are very tightly bound into the matrix. Leaching of trace elements is extremely low and transport in soil will be very slow (Proctor et al. 2000).
- Endpoint:
- adsorption / desorption
- Remarks:
- adsorption/desorption
- Type of information:
- other: data compilation and assessment
- Adequacy of study:
- weight of evidence
- Study period:
- 2006
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Study well documented. Study meets generally accepted scientific principles. Study acceptable for assessment
- Qualifier:
- according to guideline
- Guideline:
- other: DIN 38414-4:1984-10 German standard methods for the examination of water, waste water and sludge; sludge and sediments (group S); determination of leachability by water (S4)
- Deviations:
- not specified
- GLP compliance:
- no
- Type of method:
- other: data compilation and modelling
- Media:
- soil
- Radiolabelling:
- no
- Test temperature:
- not applicable (mostly data for 20 °C)
- Details on matrix:
- soil with different properties in regard to retention of certain ions
- Type:
- Kd
- Value:
- 200 - 1 000
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: As
- Type:
- Kd
- Value:
- 100 - 1 000
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Cd
- Type:
- Kd
- Value:
- 30 000 - 53 750
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Cr(total)
- Type:
- Kd
- Value:
- 6 000 - 20 000
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Cu
- Type:
- Kd
- Value:
- 2 000 - 5 000
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Hg
- Type:
- Kd
- Value:
- 750 - 1 500
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Ni
- Type:
- Kd
- Value:
- 3 500 - 5 000
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Pb
- Type:
- Kd
- Value:
- 2 000
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Zn
- Details on results (HPLC method):
- Calculations and temperature estimates by IUCLID editor
- Validity criteria fulfilled:
- not applicable
- Conclusions:
- The Kd values (L/Kg) for ABS are
As 100-1000
Pb 3500-5000
Cd 100-1000
Cr(total) 30000 -53750
Cu 6000-20000
Ni 750-1500
Hg 2000-5000
Zn 2000
There are no relevant differences in the adsorption/desorption properties of the 2 subtypes (ABS and GBS) of blast frunace slag in regard to the Kd of the trace elements tested - Executive summary:
For determination of the environmental behaviour of slags, the concentrations of the elements were determined in solid slags and in the corresponding leachates. The Kd values were calculated for REACH Registration using these existing data.
Almost all Kd values were >1000 L/kg. Exceptions were due to the very low concentrations of elements both in the solid slags as well as in the leachates. The Kd values (L/kg) for ABS are As 100-1000, Cd 100-1000, Cr(total) 30000 -53750, Cu 6000-20000, Hg 2000-5000, Ni 750-1500, Pb 3500-5000, and Zn 2000 L/kg.
These Kd values indicate that slags will retain trace elements embedded in the solid matrix/crystal lattice.
- Endpoint:
- adsorption / desorption
- Remarks:
- adsorption/desorption
- Type of information:
- other: data compilation and assessment
- Adequacy of study:
- weight of evidence
- Study period:
- 2006
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Study well documented. Study meets generally accepted scientific principles. Study acceptable for assessment
- Qualifier:
- according to guideline
- Guideline:
- other: DIN 38414-4:1984-10 German standard methods for the examination of water, waste water and sludge; sludge and sediments (group S); determination of leachability by water (S4)
- Deviations:
- not specified
- GLP compliance:
- no
- Type of method:
- other: data compilation and modelling
- Media:
- soil
- Radiolabelling:
- no
- Test temperature:
- not applicable (mostly data for 20 °C)
- Details on matrix:
- soil with different properties in regard to retention of certain ions
- Type:
- Kd
- Value:
- 1 000
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: As
- Type:
- Kd
- Value:
- 1 000
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Cd
- Type:
- Kd
- Value:
- 30 000
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Cr(total)
- Type:
- Kd
- Value:
- 6 000
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Cu
- Type:
- Kd
- Value:
- 2 000
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Hg
- Type:
- Kd
- Value:
- 1 500
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Ni
- Type:
- Kd
- Value:
- 5 000
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Pb
- Type:
- Kd
- Value:
- 2 000
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Zn
- Details on results (HPLC method):
- Calculations and temperature estimates by IUCLID editor
- Adsorption and desorption constants:
- The Kd values (L/kg) for GBS are
As 200-1000
Pb 5250
Cd 2000
Cr(total) 14400
Cu 6000
Ni 10000
Hg 4200
cyanide(total) 300
There are no relevant differences in the adsorption/desorption properties of the 2 subtypes of blast frunace slag in regard to the Kd of the trace elements tested (Oekoinstitut 2007). - Validity criteria fulfilled:
- not applicable
- Conclusions:
- The Kd values (L/Kg) for GBS are
As 1000
Cd 1000
Cr(total) 30000
Cu 6000
Hg 2000
Ni 1500
Pb 5000
Zn 2000 - Executive summary:
For determination of the environmental behaviour of slags, the concentrations of the elements were determined in solid slags and in the corresponding leachates. The Kd values were calculated for REACH Registration using these existing data.
The Kd values were >1000 L/kg. The Kd values (L/kg) of Slags, ferrous metal, blast furnace (granulated - GBS) are As 1000, Cd 1000, Cr(total) 30000, Cu 6000, Hg 2000, Ni 1500, Pb 5000, and Zn 2000 L/kg.
These Kd values indicate that slags will retain trace elements included in the solid matrix.
- Endpoint:
- adsorption / desorption, other
- Remarks:
- solubility and leachability
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- 1999-2002
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Guideline study using national guideline. Study meets generally accepted scientific principles. Study acceptable for assessment
- Qualifier:
- according to guideline
- Guideline:
- other: NT ENVIR 003
- Deviations:
- yes
- Remarks:
- but not relevant for Kd determination
- Qualifier:
- according to guideline
- Guideline:
- other: NT ENVIR 006
- Deviations:
- yes
- Remarks:
- but not relevant for Kd determination
- Principles of method if other than guideline:
- 2 types of leaching experiments performed:
ordinary availability test consisting of two leachings at neutral and acidic pH (NT ENVIR 003)
oxidised availability test at fully oxidising conditions by addition of hydrogen peroxide (NT ENVIR 006, 1999) - GLP compliance:
- no
- Type of method:
- batch equilibrium method
- Media:
- other: solid/liquid
- Specific details on test material used for the study:
- Details on properties of test surrogate or analogue material (migrated information):
No surrogate used - Radiolabelling:
- no
- Test temperature:
- room temperature (20 °C)
- Analytical monitoring:
- yes
- Details on sampling:
- For the leaching experiments, 8.00+/-0.01 g of dried material were ground to 125 µm (95 % w/w).
For the ordinary availability test two leachings at a liquid to solid ratio (L/S) of 100 were applied, first at pH 7.0 for 3 h, second at pH 4 for 4 h, or later to increase leachate concentrations, for 18 h (NT ENVIR 003). The pH was automatically controlled by a titrator using 0.5 M nitric acid and the two leachates were combined before analysis (NEN 7341, 1992).
For the oxidised availability test same leaching conditions were applied, with the exception that at fully oxidising conditions hydrogen peroxide (H2O2) was added (NT ENVIR 006, 1999). - Details on matrix:
- Slag and rock materials consist of crystalline and glassy matrix
- Type:
- other: solubility and leachability
- Value:
- > 0 - < 100 other: %
- Remarks on result:
- other:
- Remarks:
- Solubility and leachability presented in percentage in the study, see tables for more information.
- Validity criteria fulfilled:
- yes
- Remarks:
- valid analysis and reasonable data obtained. Analysis done by licenced laboratory
- Conclusions:
- Kd values of trace elements in blast furnace slag are very similar to these in natural rock materials
- Executive summary:
To elucidate the risk of the use of slags in the environment in comparison to natural rock, the 2 types of leaching experiments were performed: Ordinary availability tests consisting of two leachings at neutral and acidic pH (NT ENVIR 003) and oxidised availability tests at fully oxidising conditions by addition of hydrogen peroxide (NT ENVIR 006, 1999). 9 different types of natural rock material were used for comparison.
The leaching behaviour of natural rocks and blast furnace slags was very similar. Most of the metals exmined were less soluble from slags than from natural rock. As both total content of the trace elements of toxicological relevance, as well as their solubilites under extreme environmental conditions, were supplied, Kd values can be derived (in the report inverse Kd values are given as the precentage of the total released into leachate). In general, these Kd were lower than typical Kd values of these elements in slags. The environmental relevance of the findings was clarified by comparison with natural rocks. The slags released less trace metals than the the natural rocks, suggesting that their use in the environment poses no hazard (Tossavainen 2002).
- Endpoint:
- adsorption / desorption
- Remarks:
- desorption
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Study period:
- before 1991
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Comparable to guideline study with acceptable restrictions. Study well documented. Study meets generally accepted scientific principles. Study acceptable for assessment
- Principles of method if other than guideline:
- 24 h leaching L/S 10
- GLP compliance:
- not specified
- Type of method:
- batch equilibrium method
- Media:
- other: leaching of slag
- Specific details on test material used for the study:
- Details on properties of test surrogate or analogue material (migrated information):
not required - Radiolabelling:
- no
- Test temperature:
- estimated to be 20 °C
- Analytical monitoring:
- not required
- Details on sampling:
- L/S 10
- Type:
- Kd
- Value:
- 66 110
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Fe in ABS
- Type:
- Kd
- Value:
- 1 684
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: SiO2 in ABS
- Type:
- Kd
- Value:
- 1 312
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Ca in ABS
- Type:
- Kd
- Value:
- 97 500
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Mg in ABS
- Type:
- Kd
- Value:
- 329 220
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Mn in ABS
- Type:
- Kd
- Value:
- 7 424
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: SiO2 in GBS
- Type:
- Kd
- Value:
- 10 978
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Ca in GBS
- Type:
- Kd
- Value:
- 19 500
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Mg in GBS
- Type:
- Kd
- Value:
- 109 750
- Temp.:
- 20 °C
- % Org. carbon:
- 0
- Remarks on result:
- other: Mn in GBS
- Validity criteria fulfilled:
- not applicable
- Conclusions:
- Slags have high kd values (sorption coefficients solid/liquid) for the following metals in basic elachate:
ABS (kd [L/kg]):
Ca 1312
Mg 97500
Fe 66110
Mn 329220
SiO2 1684
GBS (kd [L/kg]):
Ca 10978
Mg 19500
Mn 109750
SiO2 7424 - Executive summary:
The environmental behaviour of slags was evaluated from the total content and the solubility of analytes in the slag. A re-evaluation of the existing data was done to determine the retention potential of slags for trace metals and other analytes. All Kd values obtained were very high suggesting that slags are only a minor source of heavy metals. The solid/liquid adsorption coefficients Kd of both ABS and GBS were high (L/kg): ABS: Ca 1312, Mg 97500, Fe 66110, Mn 329220, SiO2 1684; GBS: Ca 10978, Mg 19500, Mn 109750, SiO2 7424.
Referenceopen allclose all
Table 1. Soil-water partitioning coefficients for several trace elements (Kd in L/kg)
element |
Kd (mean) |
SD |
CV |
median |
min |
max |
log10 Kd |
N |
As |
13119 |
65086 |
4.96 |
1825 |
1.6 |
530000 |
4.12 |
66 |
B |
160 |
96 |
0.60 |
136 |
61 |
389 |
2.20 |
12 |
Ba |
3434 |
3152 |
0.92 |
2455 |
1414 |
14375 |
3.54 |
15 |
Cd |
2869 |
12246 |
4.27 |
390 |
0.44 |
192000 |
3.46 |
830 |
Cr |
14920 |
16899 |
1.13 |
4778 |
125 |
65609 |
4.17 |
64 |
Cu |
4799 |
9875 |
2.06 |
2120 |
6.8 |
82850 |
3.68 |
452 |
Hg |
8946 |
5641 |
0.63 |
7500 |
4286 |
16500 |
3.95 |
4 |
Mo |
36 |
19 |
0.52 |
38 |
14 |
52 |
1.55 |
4 |
Ni |
16761 |
45350 |
2.71 |
2333 |
8.9 |
256842 |
4.22 |
139 |
Pb |
171214 |
304089 |
1.78 |
102410 |
60.56 |
2304762 |
5.23 |
204 |
Se |
43937 |
119534 |
2.72 |
15 |
1.6 |
600000 |
4.64 |
63 |
Sr |
137 |
42 |
0.31 |
130 |
89 |
195 |
2.14 |
10 |
Zn |
11615 |
30693 |
2.64 |
1731 |
1.4 |
320000 |
4.07 |
302 |
Arithmetic Means of untransformed Kd values, SD = standard deviations, CV= coefficients of variability, medians, min = minimum, max = maximum, log (Kd), N = number of data points
Table 2. Linear Regression coefficients of Kd (L/kg) against the soil solution pH
log10 Kd |
|
parameters |
|
constant |
N |
log Kd Cd |
= |
0.49 ± 0.02 • pH |
− |
0.60 ± 0.49 |
830 |
log Kd Cu |
= |
0.27 ± 0.02 • pH |
+ |
1.49 ± 0.13 |
447 |
log Kd Ni |
= |
0.72 ± 0.05 • pH |
− |
1.75 ± 0.36 |
138 |
log Kd Pb |
= |
0.49 ± 0.04 • pH |
+ |
1.37 ± 0.25 |
204 |
log Kd Zn |
= |
0.62 ± 0.03 • pH |
− |
0.97 ± 0.21 |
298 |
Table 3. Coefficients for the Linear Regressions of Kd (L/kg) against the soil solution pH combined with Log10 of soil organic matter (SOM) or Log10 of total metal (total)
Kd Cd |
= |
0.48 ± 0.02 • pH*** + 0.82 ± 0.05 • log (SOM) |
− |
0.65 ± 0.10 |
751 |
Kd Cu |
= |
0.21 ± 0.02 • pH*** + 0.51 ± 0.06 • log (SOM) |
+ |
1.75 ± 0.12 |
353 |
Kd Ni |
= |
1.02 ± 0.09 • pH*** + 0.80 ± 0.20 • log (SOM) |
− |
4.16 ± 0.60 |
69 |
Kd Pb |
= |
0.37 ± 0.04 • pH*** + 0.44 ± 0.07 • log (total) |
+ |
1.19 ± 0.22 |
204 |
Kd Zn |
= |
0.60 ± 0.03 • pH*** + 0.21 ± 0.06 • log (total) |
− |
1.34 ± 0.23 |
298 |
a SOM, in % C.bIn mg (kg dry soil)-1.c Statistical significance: * for p < 0.1, ** for p < 0.01, *** for p < 0.001, and NS for p > 0.1.
Kd values calculated from concentrations of trace elements in solid blast furnace slags (ABS/GBS) and in slag leachates
|
Mean |
Mean leachate |
Mean Kd |
|
concentration |
concentration |
value |
|
(mg/kg) |
(mg/L) |
(L/kg) |
Aluminum |
38420 |
3.8 |
20835 |
Antimony |
ND |
ND |
ND |
Arsenic |
0.45 |
ND |
300 |
Barium |
290 |
0.22 |
1686 |
Beryllium |
8.2 |
ND |
16480 |
Cadmium |
ND |
ND |
ND |
Chromium |
120.8 |
0.0038 |
78292 |
Chromium (VI) |
ND |
ND |
ND |
Copper |
11 |
ND |
7967 |
Iron |
32440 |
ND |
1297600 |
Lead |
31 |
ND |
20667 |
Manganese |
7820 |
0.0014 |
7112857 |
Molybdenum |
3.3 |
ND |
1320 |
Mercury |
ND |
ND |
ND |
Nickel |
3.3 |
ND |
1300 |
Selenium |
4.8 |
0.0075 |
1015 |
Silver |
ND |
0.0037 |
ND |
Thallium |
ND |
ND |
ND |
Tin |
2.5 |
ND |
500 |
Vanadium |
34 |
0.010 |
11753 |
Zinc |
33 |
ND |
3348 |
ND, not detected.
There are no relevant differences in the adsorption/desorption properties of the 2 subtypes (ABS and GBS) of blast furnace slag in regard to the Kd of the trace elements tested
There are no relevant differences in the adsorption/desorption properties of the 2 subtypes (ABS and GBS) of blast furnace slag in regard to the Kd of the trace elements tested
will be calculated
Mean solubilities and Kd values of ABS
|
pH |
Fe |
SiO2 |
Ca |
Mg |
P |
Mn |
sulfate |
Cl |
F |
Na |
K |
Zn |
Pb |
Cu |
Ni |
Mean |
10.7 |
0.10 |
97 |
226 |
0.4 |
0.1 |
0.02 |
666 |
13.7 |
0.56 |
122 |
99 |
0.15 |
0.36 |
0.18 |
0.08 |
Kd (L/Kg) |
|
66110 |
1684 |
1312 |
97500 |
|
329220 |
|
|
|
|
|
|
|
|
|
Mean solubilities and Kd values of GBS
|
pH |
SiO2 |
Ca |
Mg |
P |
Mn |
sulfate |
Cl |
F |
Na |
K |
Zn |
Mean |
9 |
22 |
27 |
2 |
0.03 |
0.06 |
87 |
27 |
2.4 |
13 |
7 |
0.4 |
Kd (L/kg) |
|
7424 |
10978 |
19500 |
|
109750 |
|
|
|
|
... |
|
Temperatures are estimates by the IUCLID editor
Description of key information
High Kd values for trace elements indicate that the distribution of trace elements between slags (solid phase) and their leachates (liquid pahse) is almost exclusively on the side of the solid phase, and very low mobility of trace elements is predicted.
Key value for chemical safety assessment
Additional information
Kd values of trace elements in soils
A literature review was done on soil−liquid partitioning coefficients (Kd) of several trace elements of toxicological relevance. Although the reported values scattered, mobility and bioavailability of the elements could be predicted. The kd values especially for the metals cadmium, copper, lead, nickel, and zinc exhibited a relationships to variations in the pH of the soil solution, the content of metals and organic matter of the soil (SOM). Multiple linear regressions showed highest correlations to linear regression with pH or with pH and log of one of the other parameters. Solubility of trace metals was interpreted as competitive adsorption of metal cations and hydrogen ions.
Arithmetic Means of Kd values (L/kg) of elements in soil/water
As 13119
B 160
Ba 3434
Cd 2869
Cr 14920
Cu 4799
Hg 8946
Mo 36
Ni 16761
Pb 171214
Se 43937
Sr 137
Zn 11615 (Sauvé et al. 2000)
Kd values of trace elements of slags
Soil-to-water partition coefficients Kd of individual trace elements occurring in slag were calculated from their concentration in the solid slag, divided by their concentrations in leachate. In total, slag from 58 steel works with blast furnaces, basic oxygen furnaces (converters) and/or electric arc furnaces, were examined for leachability at acidic and neutral pH values.
The calculated Kd values are higher than 1000 L/kg with few exceptions due to calculation procedure using half the limit of detection as an estimate for concentration in leachates. These calculated results comprise arsenic and tin in blast furnace slag (Kd= 300 and 500 L/kg, for arsenic and tin, respectively) and mercury in the EAF slag (Kd= 900 L/kg). With very low levels both in the slag and in the leachate, the following Kd's were calculated: 700 L/kg for molybdenum in BOS, 535 L/kg for chromium-VI in EAF, and 819 L/kg for arsenic in EAF.
The Kd values of different slags were similar. Their differences between the slags did not exceed one order of magnitude.
The high Kd values suggest that the trace elements are very tightly bound into the matrix. Leaching of trace elements is extremely low and transport in soil will be very slow (Proctor et al. 2000).
These results were confirmed by data on total trace element levels in slags and the corresponding leaching data taken from a report of the German Oekoinstitut. The Kd values (L/Kg) calculated for ABS are
As 2500
Pb 3500
Cd 1667
Cr(total) 10000
Cu 4000
Ni 7143
Hg 3500
Zn 7500
cyanide(total) 250
The Kd values (L/kg) for GBS are
As 3214
Pb 5250
Cd 2000
Cr(total) 14400
Cu 6000
Ni 10000
Hg 4200
cyanide(total) 300
There are no relevant differences in the adsorption/desorption properties of the 2 subtypes of blast furnace slag in regard to the Kd of the trace elements tested (data taken from Oekoinstitut 2007).
To determine the kd values of trace elements of toxicological relevance in the slags ABS, BOS, and EAF C, existing concentration data of the BfG of trace elements in solid slag and natural rocks were compared with their respective concentrations in leachates of slags and natural rocks.
The kd values of Hg and Tl could not be determined, because no data had been measured in leachates. The Kd values of As and Cd are low (e.g. >20 L/Kg) because these elements (and Hg and Tl) are not present in slags and basalt at relevant levels. The same is most likely correct for Pb. For Ni (< 700, >4000 L/kg), Cu (> 9400, > 6000 L/kg), Zn (> 40000, >6600 L/kg) and Cr (> 800000, > 10000 L/kg) high Kd values have been obtained, suggesting a very tight binding of these elements into slag and basalt, respectively (data taken from BfG 2008).
The environmental behaviour of slags was evaluated from the total content and solubility of analytes in the slags. A simple re-evaluation of the existing data was done to determine the retention potential of slags for trace metals and other analytes. All Kd values obtained were very high suggesting that the analytes examined are effectively retained by slags. The solid/liquid adsorption coefficients Kd of both ABS and GBS were high (L/kg): ABS: Ca 1312, Mg 97500, Fe 66110, Mn 329220, SiO2 1684; GBS: Ca 10978, Mg 19500, Mn 109750, SiO2 7424 (data taken from LECES 1991).
Kd values of ABS and GBS in comparison with natural rocks
To elucidate the risk of the use of slags in the environment in comparison to natural rock, the 2 types of leaching experiments were performed: Ordinary availability tests consisting of two leachings at neutral and acidic pH (NT ENVIR 003) and oxidised availability tests at fully oxidising conditions by addition of hydrogen peroxide (NT ENVIR 006, 1999). 9 different types of natural rock material were used for comparison.
The leaching behaviour of natural rocks and blast furnace slags was very similar. Most of the metals exmined were less soluble from slags than from natural rock. As both total content of the trace elements of toxicological relevance, as well as their solubility under extreme environmental conditions, were supplied, Kd values can be derived (in the report inverse Kd values are given as the percentage of the total released into leachate). In general, these Kd were lower than typical Kd values of these elements in slags. The environmental relevance of the findings was clarified by comparison with natural rocks. The slags released less trace metals than the natural rocks, suggesting that their use in the environment poses no hazard (Tossavainen 2002).
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