Tris[oxalato(2-)]dilutetium

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption, other

Remarks:

field study

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Suspended matter and water samples were taken from five sampling locations in the Ionian Sea and the Strait of Sicily and were analysed for Lu. Log Kp values for suspended matter-water were calculated from analysed concentrations of Lu in paired samples.

GLP compliance:

not specified

Type of method:

other: field study

Media:

suspended matter

Radiolabelling:

no

Test temperature:

Depending on the depth (temperature decreasing with increasing depth) but overall between 14.56 and 25.90°C for all samples taken at the five locations.

Analytical monitoring:

yes

Details on sampling:

- Samples were collected in the early summer of 1999 during the JUVENILE 99 cruise, aboard the RV Urania.
- At five locations (S24 and S470 in the Ionian Sea and S128, S455 and S458 in the Strait of Sicily), paired samples of water and suspended matter were taken.
- Different samples were taken at different depths at each sampling location, with depth overall ranging between 10 and 650 m.
- The sampling system consisted of a Neil-Brown CTD rosette frame and 24 x 12 L Teflon-lined GoFlo bottles. Upon recovery of the GoFlo bottles, water samples were immediately filtered inside the shipboard through 0.4 µm Millipore filters, using a Teflon tubing apparatus. Samples were acidified to pH 1-2 with HNO3 Merck ULTRAPUR and stored in hot-acid washed polyethylene bottles.

Details on matrix:

No details reported on matrix.

Details on test conditions:

No further details reported.

Computational methods:

Concentrations of the element under consideration analysed in suspended matter were divided by dissolved concentrations of the element analysed in filtered seawater sampled at the same sampling location (including same depth) to obtain Kp values.

Phase system:

suspended matter-water

Type:

log Kp

Value:

>= 3.66 - <= 5.1 L/kg

Remarks on result:

other: range for all paired samples

Phase system:

suspended matter-water

Type:

log Kp

Value:

4.04 L/kg

Remarks on result:

other: mean for all paired samples

Conclusions:

In this study, samples of suspended matter and (filtered) seawater were taken from two sampling locations in the Ionian Sea and 3 sampling locations in the Strait of Sicily and analysed for Lu. Log Kp suspended matter-water values were calculated from the results obtained for paired samples and ranged between 3.66 and 5.10 L/kg, the mean being 4.04 L/kg.

Reference 2

Endpoint:

adsorption / desorption, other

Remarks:

field study

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Log Kp values calculated from analysed concentrations of Lu in field samples.

GLP compliance:

not specified

Type of method:

other: field study

Media:

suspended matter

Radiolabelling:

no

Test temperature:

Ambient temperature, not specified

Analytical monitoring:

yes

Details on sampling:

Water samples were collected from a fishing boat using a hand-made polyethylene sampler consisting of a 5 L Niskin bottle. Upon recovery of the bottles, water samples were filtered through 0.2 μm Millipore® filters, using a Teflon tubing apparatus. The filtration was done immediately on board, and samples were always transported within 8 h to the laboratory. Filtered samples were acidified to pH 1–2 with HNO3 (Merck ULTRAPUR®) and stored in hot-acid-washed polyethylene bottles.
Seafloor sediments were sampled with a Van Veen bucket in the same stations where seawater and suspended materials in the water column were collected.
In order to increase the signal/noise ratio in the studied seawaters, for Y and REE analyses 1000 mL of each sample was pre-concentrated with a CHELEX 100® (100–200 mesh) ion exchange resin:
• pH value of each seawater sample was set to 6.0 ± 0.1 with CH3COONH4, and an aliquot of each seawater sample passed on an 8-cm-long column filled with CHELEX-100 (100–200 mesh) previously cleaned and conditioned.
• REY were eluted with 5 mL of HNO3 3.5 M, giving a 100-fold enrichment factor. Details of the procedures are reported in the literature.

Details on matrix:

Sediment and suspended matter samples taken from several sampling locations in the western Gulf of Thailand.

Details on test conditions:

Seawater and suspended matter samples were taken at 0.5 m depth and/or at greater depths between 5 and 18 m.

Computational methods:

Concentrations of the element under consideration analysed in suspended matter were divided by dissolved concentrations of the element analysed in filtered seawater sampled at the same sampling location (including same depth) to obtain Kp values.
For sediment-water Kp values, the concentration analysed in the sediment sample was divided by the dissolved concentration in filtered seawater from the greatest sampling depth.

Phase system:

suspended matter-water

Type:

log Kp

Value:

>= 5.09 - <= 6.58 L/kg

Remarks on result:

other: range for all samples

Phase system:

suspended matter-water

Type:

log Kp

Value:

5.99 L/kg

Remarks on result:

other: mean value for all samples

Station number	Lu(nmol/L)	Lu in SPM (mg/kg)	Kp SPM (L/kg)	Log Kp
128a	0.00886	0.347	223837.1	5.349932
129a	0.00371	0.549	845736	5.927235
130a	0.01772	1.632	526372.1	5.721293
131a	0.01032	0.876	485133	5.685861
132a	0.02777	0.596	122661.1	5.088707
133a	0.01486	1.218	468451.8	5.670665
134a	0.01486	0.984	378453.6	5.578013
135a	0.00714	2.412	1930703	6.285715
138a	0.016	1.869	667614.4	5.824526
140a	0.00486	0.876	1030159	6.012904
141a	0.00314	0.433	788124.2	5.896595
142a	0.00486	1.192	1401769	6.146676
143a	0.00457	0.759	949209.3	5.977362
144a	0.02343	0.823	200753.9	5.302664
145a	0.00429	1.593	2122242	6.326795
146a	0.008	0.764	545807.9	5.73704
147a	0.00229	0.765	1909248	6.280862
148a	0.00286	0.527	1053128	6.022481
149a	0.00247	0.869	2010755	6.303359
150a	0.00286	1.768	3533073	6.548153
151a	0.00629	1.116	1014028	6.00605
152a	0.00629		NA	NA
153a	0.00229	0.839	2093934	6.320963
128b	0.00457	0.6	750363.1	5.875271
129b	0.00305	1.332	2495978	6.397241
140b	0.002	1.331	3803509	6.580184
141b	0.00229	1.216	3034831	6.482135
147b	0.004	0.816	1165914	6.066667
148b	0.00286	0.855	1708585	6.232636
150b	0.00744		NA	NA
128c	0.00371	1.348	2076598	6.317352
129c	0.00629	0.899	816855.9	5.912145
130c	0.0079	0.9	651106.2	5.813652
131c	0.00972	1.137	668544.9	5.825131
140c	0.00457		NA	NA
141c	0.00457	0.562	702840.1	5.846857
142c	0.00429	1.187	1581357	6.19903
148c	0.00286	0.928	1854464	6.268218
149c	0.00514	0.285	316897	5.500918
150c	0.00458	1.685	2102669	6.322771
151c	0.00457	0.843	1054260	6.022948
152c	0.00286	0.382	763367.6	5.882734

 

Conclusions:

In this study, samples of suspended matter and (filtered) seawater were taken from various sampling sites in the western Gulf of Thailand and analysed for Lu. Log Kp suspended-matter values were calculated from the results obtained for paired samples and ranged between 5.09 and 6.58 L/kg, the mean being 5.99 L/kg.

Reference 3

Endpoint:

adsorption / desorption, other

Remarks:

multitracer experiment

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Multitracer experiment. The adsorption of elements on model samples of marine particulates, including deep-sea and near-shore sediments, was studied.

GLP compliance:

no

Type of method:

other: multitracer experiment

Media:

sediment

Radiolabelling:

yes

Remarks:

radioactive multitracers are used

Test temperature:

25°C

Analytical monitoring:

yes

Details on sampling:

The suspension was shaken in an 8-shape mode with a shaker at 25° C. After centrifugation, a portion of the supernatant solution was pipetted.

Details on matrix:

Matrix 1
COLLECTION AND STORAGE
- Geographic location: deep-sea sediment Penrhyn Basin (12°26.44'S, 157°57.20'W, depth 5351 m)
- Storage conditions: in artificial seawater (storage 2 mg/cm³ artificial seawater), pH of suspension adjusted to 7.5

Matrix 2
COLLECTION AND STORAGE
- Geographic location: near-shore sediment Suruga Bay (34°44.52.'N, 169°27.05'E, depth ca. 600 m)
- Storage conditions: in artificial seawater (storage 2 mg/cm³ artificial seawater), pH of suspension adjusted to 7.5

Details on test conditions:

TEST CONDITIONS
10 cm3 of artificial sea water and 0.01 cm3 of a multitracer solution were put into a polyethylene bottle. After the pH was adjusted to 7.5 with a 1 M Na2CO3 solution, the adsorbent suspension was added. Resulting concentrations of adsorbent were 0.1, 0.05 and 0.01 mg/cm3. pH of suspension was readjusted to 7.5 when necessary.

Artifical seawater containing 23.94 g NaCl and 0.196 g NaHCO3 / 1000 cm3 water was used.

TEST SYSTEM
- Type, size and further details on reaction vessel: polyethylene bottle.
- Amount of soil/sediment/sludge and water per treatment: 10 cm3 artificial seawater + 0.01 cm3 of a multitracer solution + 0.1, 0.05 or 0.01 mg adsorbent/cm3.
- Suspension was shaken in a 8-shape mode with a shaker at 25°C.
- To reach equilibrium, 1-2 days of shaking was needed (not further specified for Lu).

Computational methods:

Kads = (Aads/m)/(Asoln/V) = ((Ai - Af)/Af)(V/m)
Aads = radioactivity in the adsorbent after adsorption equilibrium
Asoln = radioactivity in the solution after adsorption equilibrium
V = volume of the solution (cm3)
m = amount of adsorbent (g)
Ai = radioactivity in the solution before adsorption equilibrium
Af = radioactivity in the solution after adsorption equilibrium

Phase system:

sediment-water

Type:

log Kp

Value:

5.41 L/kg

Temp.:

25 °C

pH:

7.5

Matrix:

deep-sea sediment

Phase system:

sediment-water

Type:

log Kp

Value:

5 L/kg

Temp.:

25 °C

pH:

7.5

Matrix:

near-shore sediment

Conclusions:

In this multitracer experiment, the log Kp for Lu for deep-sea and near-shore sediment in artificial seawater was determined to be 5.41 and 5.0 L/kg, respectively.

Reference 4

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

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

GLP compliance:

not specified

Type of method:

batch equilibrium method

Media:

soil

Radiolabelling:

yes

Test temperature:

not reported

Analytical monitoring:

yes

Details on sampling:

Referred to previous papers (Yin et al., 1966; Du et al., 1996a, 1996b; Tao et al., 1996a, 1996b).
Contact time was 2 h.

Details on matrix:

Calcareous, sierozen soil, samples taken from top layer (0-20 cm) of cultivated land of Yuzhong county in the middle Gansu province, China.

Details on test conditions:

Experiments were conducted with untreated soil, treated soil to remove CaCO3, and treated soil to remove both CaCO3 and organic matter.
Ratio of solution to soil was 12.5 g/L.
Contact time 2 h.

Computational methods:

Kp calculations based on change in activity in aqueous solution before and after adsorption.
If the activity in the supernatant after adsorption was lower than the minimum detectable activity of the detector, Kp was roughly estimated from the activity before adsorption and the minimum detectable activity.

Phase system:

soil-water

Type:

log Kp

Value:

3.73 L/kg

Remarks on result:

other: untreated soil

Adsorption and desorption constants:

Log Kp soil in untreated soil was 3.73.
Log Kp soil in treated soil (CaCO3 or both CaCO3 and organic matter removed) was also 3.73.

Details on results (Batch equilibrium method):

In this study, the log Kp for lutetium in a soil-water system was determined to be 3.73 L/kg (untreated soil). Since the values obtained in soil treated to remove CaCO3 and/or organic matter were similar to that obtained in untreated soil, it was concluded that adsorption of lutetium is largely determined by the oxides and silicates and not by CaCO3 or organic matter.

Conclusions:

In this study, adsorption of Lu was investigated using cultivated Chinese soil and radiolabeled Lu. The log Kp was determined to be 3.73 L/kg in untreated soil.

Reference 5

Endpoint:

adsorption / desorption, other

Remarks:

field study

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Sediment, pore water, suspended matter, and water samples were taken in the Forsmark area, Baltic Sea, and analysed for Lu.

GLP compliance:

not specified

Type of method:

other: field study

Media:

other: sediment and suspended matter

Radiolabelling:

no

Test temperature:

between 2.3 and 12.3°C during sampling

Analytical monitoring:

yes

Details on sampling:

- Location and timing: all samples collected between 12-20 April 2005 in the bay between the north side of the islands of Stor and Lill-Tixlan, between the Forsmark nuclear power station and the town of Öregrund, NW Baltic Proper.
- Integrated water samples (10 L) collected from 0-4 m depth using a metal-free pump.
- Particulate organic matter in the water column was sampled through filtration of the water samples.
- Sediment: Kajak cores were taken at 7-8 m depth and sliced into two sections (0-3 cm and 3-6 cm).
- Pore water was extracted by centrifugation (20 min at 4500 rpm) from sediment samples.

Details on matrix:

no details reported

Details on test conditions:

field test

Computational methods:

Partitioning coefficients were calculated by dividing Lu concentration in solid phase by Lu concentration in water (L/kg).
Kpsuspended matter-water as well as Kpsediment-pore water were calculated (the latter for upper layer (0-3 cm) and lower layer (3-6 cm)).

Phase system:

suspended matter-water

Type:

log Kp

Value:

4 L/kg

Remarks on result:

other: Concentrations in filtered water were below the detection limit, therefore the detection limit was used as aquatic Lu concentration.

Phase system:

solids-water in sediment

Type:

log Kp

Value:

2.83 L/kg

Remarks on result:

other: Concentrations in sediment and pore water of upper sediment layer (0-3 cm) were used. Concentrations in filtered pore water were below the detection limit, therefore the detection limit was used as aquatic Lu concentration.

Details on results (Batch equilibrium method):

For the lower sediment layer (3-6 cm), a log Kpsediment-pore water of 2.92 L/kg was obtained (Lu concentrations in both pore water and sediment (particulate phase) were however below the detection limit, consequently the detection limits in the respective phases were used for calculation of the log Kp).

Conclusions:

In this study, water, suspended matter, sediment, and pore water samples were taken in the Forsmark area, Baltic Sea, and analysed for lutetium. The log Kpsuspended matter-water was calculated to be 4 L/kg, using the detection limit as aquatic lutetium concentration since lutetium was not detectable in the water phase. The log Kpsediment-pore water for the upper sediment layer (0-3 cm) was determined to be 2.83 L/kg, however, here too, the detection limit was used as aquatic lutetium concentration since lutetium was not detectable in the pore water.

Reference 6

Endpoint:

adsorption / desorption, other

Remarks:

field study

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Sediment and pore water samples were collected from two rivers which receive wastewater from urban Hanoi (Vietnam) and analysed for Lu.

GLP compliance:

not specified

Type of method:

other: field study

Media:

sediment

Radiolabelling:

no

Test temperature:

not reported

Analytical monitoring:

yes

Details on sampling:

- Sediment samples collected from To Lich and Kim Nguu rivers, both of which receive wastewater from urban Hanoi, Vietnam. Samples collected from three sites in both rivers with a stainless steel Kajak core sediment sampler equipped with a polymethylmethacrylat inner liner with an inner diameter of 46 mm. Three replicates were collected from each site. Core samples were subdivided into sections 0-10cm, 10-20cm, 20-30cm. Sediment samples were dried at 45°C until constant weight, passed through a 2 mm stainless steel sieve and pulverised in an agate mortar.
- Pore water was extracted from sediment samples: sediment from 0-10cm depth was transferred to polypropylene büchner funnel with 25 µm mesh nylon filter and a minimum of 15 mL pore water was extracted under suction of 10 kPa. Pore water was filtered through a 0.45 µm nylon filter (Millipore) and acidified with 0.1 mL 70% HNO3 (Baker Instra-Analysed).

Details on matrix:

- % organic carbon: 1.2-5.3% in To Lich river samples, 1.8-10.6% in Kim Nguu rivers
- pH of pore water was 7.4-8.1
- redox potential of pore water was -257 to -185 mV

Details on test conditions:

field study

Computational methods:

Partitioning coefficients were calculated by dividing Lu concentration in sediment by Lu concentration in pore water (L/kg).

Phase system:

solids-water in sediment

Type:

log Kp

Value:

> 4.89 L/kg

% Org. carbon:

>= 1.2 - <= 10.6

Remarks on result:

other: both sorption and precipitation processes may be reflected in the log Kp value - note that the log Kp was reported to be > 4.89 because pore water concentrations were below the limit of detection (i.e. < 0.0015 µg/L) in all cases

Conclusions:

In this study, samples of sediment and pore water were taken along two rivers receiving wastewater from Hanoi, Vietnam, and analysed for Lu. Log Kp sediment-pore water values higher than 4.89 L/kg were reported. However, reliability is restricted, because the pore water concentrations were below the limit of detection (i.e. < 0.0015 µg/L) in all cases, leading to an unbound log Kp value, and because precipitation processes may have been involved in sediment next to sorption processes.

Reference 7

Endpoint:

adsorption / desorption, other

Remarks:

field study and laboratory study with field samples

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Field study in which Lu concentrations were determined in both surface water, pore water, sediment, and suspended matter. Samples were taken from 6 sampling locations in the Rhine-Meuse estuary in The Netherlands. Further, also a lab study was performed using field samples.

GLP compliance:

not specified

Type of method:

other: both field study and laboratory study using field samples

Media:

other: sediment and suspended matter

Radiolabelling:

no

Test temperature:

Field sampling: no temperature range given.
Laboratory experiment: 15 °C

Analytical monitoring:

yes

Details on sampling:

Field sampling:
- Surface-water samples, suspended solids, and sediments (through 25-cm-deep, box-core sampling) were collected during June and July 1997 at six locations in the Rhine-Meuse estuary.
- Sampling locations: Nieuwe Maas, Nieuwe Maas, First Petroleum Harbour, Botlekhaven, Northsea Loswal Noord, and Northsea Terheide 30. Locations 1, 2, 6 are relatively clean. Locations 3, 4 are directly influenced by industrial discharges, and location 5 is a disposal site for sediments that are contaminated through industrial discharges.
- Surface water samples were 0.45 µm filtered.
- Pore water samples were obtained by positive-pressure filtration (0.45 µm).
Lab study (location 2 sediment and water):
- Samples taken after 10 days.

Details on matrix:

- Sampling: see above.
- Organic carbon (%) median (range): 5.9 (4.0-24.2) in suspended solids of the six locations, 1.94 (0.08-3.82) in sediments of the six locations, 2.13 (0.88-2.81) for the sediments used in the lab study.

Details on test conditions:

Field study: no specific test conditions.
Laboratory study:
For every assay, two acid-rinsed polystyrene aquaria (replicates) were filled with sediments (1750 g wet weight) and seawater (4 L) from the appropriate location (2). Standard conditions: pH = 8.1, salinity 30 g/L, no addition of complexing agents, exposure time 10 d.
Further assays were conducted with diversified conditions:
- varying pH: 7.1, 7.7, 8.1 and 8.5;
- varying salinity: 10, 20 and 30 g/L
- addition of complexing agents: 500 mg H(PO4)2-, 400 µg F-

Computational methods:

Indicative adsorption coefficients could only be calculated using the median Lu concentrations reported for the six locations and the laboratory study in pore water, surface water, sediments and suspended solids.

Phase system:

sediment-water

Type:

log Kp

Value:

ca. 5.6 L/kg

Remarks on result:

other: calculated using median values for field samples (sediment and surface water)

Phase system:

solids-water in sediment

Type:

log Kp

Value:

ca. 5.2 L/kg

Remarks on result:

other: calculated using median values for field samples (sediment and pore water)

Phase system:

suspended matter-water

Type:

log Kp

Value:

ca. 5.76 L/kg

Remarks on result:

other: calculated using median values for field samples (suspended matter and surface water)

Phase system:

sediment-water

Type:

log Kp

Value:

ca. 5.28 L/kg

Remarks on result:

other: calculated using median values for laboratory study samples (sediment and surface water)

Phase system:

solids-water in sediment

Type:

log Kp

Value:

ca. 4.67 L/kg

Remarks on result:

other: calculated using median values for laboratory study samples (sediment and pore water)

Adsorption and desorption constants:

see above

Statistics:

Median values used for Kp calculation, hence Kp values only indicative. Paired values for aqueous and solid phase not reported.

Conclusions:

In this study, lutetium concentrations were determined in surface water, pore water, sediment and suspended solids of six locations in the Rhine-Meuse estuary (the Netherlands) as well as in a lab study using field samples of one of the six locations. Only medians and ranges were reported, therefore, only indicative adsorption coefficients could be calculated using the median values. Log Kp values for sediment-surface water were 5.60 L/kg (field) and 5.28 L/kg (laboratory). Log Kp values for sediment-pore water were 5.20 L/kg (field) and 4.67 L/kg (laboratory). The log Kp value for suspended solids-surface water was 5.76 L/kg (field).

Reference 8

Endpoint:

adsorption / desorption, other

Remarks:

field study

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Field study in which Lu concentrations were determined in surface water and sediment. Samples were taken from 15 different stations located in 4 different estuarine areas in Japan.

GLP compliance:

not specified

Remarks:

field study, results reported in scientific literature, no information on GLP

Type of method:

other: field study

Media:

sediment

Radiolabelling:

no

Test temperature:

Field water samples: 17.4-27.0°C with a geomean of 22.1°C

Analytical monitoring:

yes

Details on sampling:

Sampling locations:
- Near the mouth of the Mabechi River off Aomori (August 2007). Estuarine area located on the North Pacific side of Honshu. Water depth up to 60 m. 3 sampling stations.
- Near the mouth of the Mogami River off Yamagata (August 2007). Estuarine area located on the Japan sea side of Honshu. Water depth up to 55 m. 3 sampling stations.
- Near the mouth of the Kuma River off Kumamoto (November 2007). Semiclosed estuarine area located in the Yatsushiro Sea on the North Pacific Ocean side of Kyushu. Water depth up to 30 m. 3 sampling stations.
- Near the mouth of the Yura River off Kyoto (seasonal differences investigated - July, September, November 2007). Semiclosed estuarine area located in the SW part of Honshu at Wakasa Bay on the Japan Sea. Water depth up to 55 m. July: 3 sampling stations. September: 4 sampling stations. November: 2 sampling stations.

Water samples:
In each of the 4 estuarine areas, bottom water samples were taken 1-15 m above the seafloor at 2–4 stations that were located at different distances from the mouth of each river.
- Water was collected in acid-cleaned, Teflon-coated, 5-L horizontal Niskin X sampling bottles (General Oceanics).
- For metal analysis samples were filtered (< 0.2 µm fraction) with a precleaned 0.2 µm pore size capsule cartridge-type polytetrafluoroethylene filter (Advantec) connected to a sampling bottle spigot and then the water sample was gravity-filtered into a precleaned 250-mL low density polyethylene bottle. The filtrates were acidified with 0.1 mL of 68% superpure grade HNO3 (Tama Chemicals, AA-100) per 100 mL. The acidified solutions (pH < 2) were kept in a refrigerator (5°C) until the analyses for dissolved elements were done.

Sediment samples:
Surface sediments were collected at the same sampling point as for the water collection in the estuarine areas using an Eckmann bottom corer (Miyamoto Riken Inc., A-15). The surface sediment samples were transferred to polyethylene bags and stored in a refrigerator. The raw surface sediments were dried at room temperature, and then sieved (2 mm) to remove large particles and shell fragments before being dried at 105°C to a constant weight, which indicated the complete removal of moisture. Afterwards, the dried samples were transferred to glass bottles and stored in a dark place until analysis.

Details on matrix:

Both sandy and muddy sediments were observed, color from brown over dark brown and very dark grey to black.
Water content of sediments between 26 and 70% (geometric mean 42%).
Loss on ignition between 2.1 and 9.3% (geometric mean 4.8%).

Details on test conditions:

Field study.
Temperature range of water samples: 17.4-27°C
Salinity range of water samples: 31.9-34.2 g/L
pH range of water samples: 8.1-8.4
DO (dissolved oxygen) concentration in water samples: 6.7-8.3 mg/L
SPM (suspended particulate matter) concentration: 0.1-4.1 mg/L
DOC (dissolved organic carbon) concentration: 0.82-1.36 mg/L

Computational methods:

Kd = Cs/Cb
where Cs (g/kg) and Cb (g/L) represent the total element concentration in surface sediment and the dissolved element concentration in estuarine water, respectively.
In the publication, the factor of 0.2 was added because in the International Atomic Energy Agency (IAEA) Technical Report Series 422, 20% of the total concentration of each element in sediment was defined as exchangeable fraction with the aqueous phase. Because of doubts on the application of this factor it was not used here (i.e. the value in the study was divided by 0.2).

Phase system:

sediment-water

Type:

log Kp

Value:

>= 5.52 - <= 6.39 L/kg

Remarks on result:

other: range for all paired samples

Phase system:

sediment-water

Type:

log Kp

Value:

6.06 L/kg

Remarks on result:

other: mean for all paired samples

Conclusions:

In this study, samples of sediment and water were taken from 15 sampling stations in 4 Japanese estuaria and analysed for Lu. Log Kp values ranged from 5.52 to 6.39 L/kg, the mean being 6.06 L/kg.

Reference 9

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

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

GLP compliance:

not specified

Type of method:

batch equilibrium method

Media:

soil

Radiolabelling:

yes

Test temperature:

ca. 25°C

Analytical monitoring:

yes

Details on sampling:

After shaking for 2 h, the two phases were separated by centrifugation at 4000 rpm for 30 min.

Details on matrix:

1. Calcareous soil: irrigating soil, surface 0-20 cm, cultivated land in Jiuquan county of the Gansu corridor, China. pH 8.30, 1.72% oc, 13.5% CaCO3, CEC 5.94 meq./100 g soil, 10.4% clay.
2. Red earth: coastal sandy soil, from the coast of Da-Ya Bay of Guangdong province, China. pH 6.4, 3.28% oc, no CaCO3, CEC 6.82 meq./100 g soil, 2.0% clay.

Details on test conditions:

Batch equilibrium experiments at ca. 25°C.
50 mg soil and 4.0 mL aqueous solution containing 2.0 mL of multitracer solution and 2.0 mL of compound solution in a polyethylene test tube.
Test tubes shaken for 2 h.

Computational methods:

Values of Kp calculated from the difference in activities measured before and after sorption in the aqueous solution. If not detectable, minimum detectable activities were used for Kp calculation.

Phase system:

soil-water

Type:

log Kp

Value:

3.71 L/kg

Temp.:

25 °C

% Org. carbon:

1.72

Remarks on result:

other: calcareous soil, minimum detectable activity used

Phase system:

soil-water

Type:

log Kp

Value:

3.7 L/kg

Temp.:

25 °C

% Org. carbon:

3.28

Remarks on result:

other: red earth

Conclusions:

In this multitracer study, the adsorption of Lu to two Chinese soils, a calcareous soil and a sandy red earth, was investigated in a batch equilibrium experiment. Log Kp values were 3.71 and 3.70 for the calcareous soil and red earth, respectively. The lower value is less reliable because estimated using minimum detectable activity.

Reference 10

Endpoint:

adsorption / desorption, other

Remarks:

field study

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Sediment and pore water samples were taken at five locations in The Netherlands. These samples were analysed for Lu.

GLP compliance:

not specified

Type of method:

other: field study

Media:

sediment

Radiolabelling:

no

Test temperature:

Temperature at sampling occasions between 18 and 21°C.

Analytical monitoring:

yes

Details on sampling:

Five locations in The Netherlands, four of them in highly industrialised region around city of Rotterdam. All sampling sites in catchment of Rhine and Meuse rivers. 1. Veluwemeer, 2. Botlekpark, 3. Kralingse Plas, 4. Nieuwe Maas, 5. Charlois.
Samples were taken in August and September 2000.
Pore water samples (n=3) were extracted in situ using Rhizon soil moisture samplers (MOM type, Eijkelkamp Agrisearch Equipment, Giesbeek, The Netherlands).
Sediment samples (n=3) were collected with a bottom sampler according to Ekman-Birge (Hydro-bios, Kiel, Germany).

Details on matrix:

Average pH of sampling locations at time of sampling was between 6.92 and 7.55 for pore water.
No characteristics given for sediment.

Details on test conditions:

Field study.

Computational methods:

Kp sediment values were calculated dividing concentration in sediment (mg/kg) by concentrations in pore water (mg/L).
This was done separately for the < 2 mm sediment fraction and the < 0.063 mm sediment fraction.

Phase system:

solids-water in sediment

Type:

log Kp

Value:

>= 4.85 - <= 5.1 L/kg

Remarks on result:

other: range derived from Figure 12 (< 2-mm sediment fraction)

Concentration of test substance at end of adsorption equilibration period:

The lanthanide concentrations measured in the < 0.063-mm sediment fraction were similar as those in the < 2-mm sediment fraction for three out of the five sampled locations. For the locations Nieuwe Maas and Veluwemeer, the < 0.063-mm sediment fraction however contained higher lanthanide concentrations than the sediment fraction < 2 mm. These locations are those with the lowest concentrations of lanthanides measured in the < 2-mm fraction and the highest in the < 0.063-mm fraction. This is due to exclusion of the relatively high sand fraction of these sediments, which for the most part is > 0.063 mm and contains low lanthanide concentrations.

Conclusions:

In this study, sediment and pore water samples were taken at five locations in The Netherlands in the Rhine-Meuse catchment. Lu was determined in all samples and log Kp sediment-pore water was reported (also in figures) to range from 4.85 to 5.1 L/kg in the < 2-mm sediment fraction.

Reference 11

Endpoint:

adsorption / desorption, other

Remarks:

field study

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Water, suspended matter, and sediment samples were taken from 8 locations along the Yangtze River and analysed for Lu. Log Kp values were calculated from analysed concentrations of Lu in the field samples.

GLP compliance:

not specified

Type of method:

other: field study

Media:

other: sediment and suspended matter

Radiolabelling:

no

Test temperature:

Ambient temperature, not specified.

Analytical monitoring:

yes

Details on sampling:

Samples of water, suspended matter and sediments were taken simultaneously in July-August, 1992. Industrially polluted areas and municipal waste water outlets were avoided. Unfiltered water samples were preserved for analysis of total amount of REEs. Filtered water (through 0.45 µm filtration membranes) was preserved for analysis of the dissolved fraction of REEs. Both unfiltered and filtered water samples were acidified to a pH < 2 with ultra-pure HNO3. Suspended matter samples were taken from the membranes directly. The suspended matter and sediments were air dried, and passed through a 20 mesh sieve for speciation analysis.
For analysis of the contents of REEs, the suspended matter and sediments were also ground until all the samples passed a 100 mesh sieve.

Details on matrix:

Eight sampling locations along the mainstream of the Yangtze River - no further details on matrix reported.

Details on test conditions:

No further details reported.

Computational methods:

For suspended matter-water Kp values, the concentration of the element under consideration analysed in suspended matter was divided by the dissolved concentration of the element analysed in filtered water samples.
For sediment-water Kp values, the concentration of the element under consideration analysed in the sediment sample was divided by the dissolved concentration of the element analysed in filtered water samples.

Phase system:

suspended matter-water

Type:

log Kp

Value:

>= 4.82 - <= 5.12 L/kg

Remarks on result:

other: range for all samples

Phase system:

suspended matter-water

Type:

log Kp

Value:

5.02 L/kg

Remarks on result:

other: mean value for all samples

Phase system:

sediment-water

Type:

log Kp

Value:

>= 4.8 - <= 5.11 L/kg

Remarks on result:

other: range for all samples

Phase system:

sediment-water

Type:

log Kp

Value:

5.01 L/kg

Remarks on result:

other: mean value for all samples

Conclusions:

In this study, samples of suspended matter, sediment, and water were taken from 8 sampling sites in the Yangtze River and analysed for Lu. Log Kp suspended matter-water values were calculated from the results obtained for paired samples and ranged between 4.82 and 5.12 L/kg, the mean being 5.02 L/kg. Log Kp sediment-water values were also calculated from the results obtained for paired samples and ranged between 4.80 and 5.11 L/kg, the mean being 5.01 L/kg.

Reference 12

Endpoint:

adsorption / desorption, other

Remarks:

field study and lab study with field samples

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Qualifier:

no guideline followed

Principles of method if other than guideline:

The concentration of Lu in water and sediment at state of equilibrium was measured in laboratory tests and in the field and Kp values were calculated.

GLP compliance:

no

Type of method:

other: field study and lab experiment with field samples

Media:

sediment

Radiolabelling:

no

Test temperature:

no data

Analytical monitoring:

yes

Details on sampling:

Samples of sediment, pore water and surface water were taken at Nieuwe Maas, Rhine estuary, the Netherlands.
Samples in the laboratory study were taken after 10 days.
All water samples 0.45 µm filtered.

Details on matrix:

- Details on collection location: Nieuwe Maas , Rhine estuary, The Netherlands, three different collection times.
- pH at time of collection: 8-8.5
- Organic carbon (%): 0.88, 2.17 and 2.77 % at different sample collection times

Details on test conditions:

Laboratory experiment: duration time 10 d

Computational methods:

Kp sediment-surface water and Kp sediment-pore water distribution coefficients were calculated using measured concentrations in solid and aqueous phase.

Phase system:

sediment-water

Type:

log Kp

Value:

5.3 L/kg

Remarks on result:

other: lab (sediment and surface water)

Phase system:

sediment-water

Type:

log Kp

Value:

5.87 L/kg

Remarks on result:

other: field (sediment and surface water)

Phase system:

solids-water in sediment

Type:

log Kp

Value:

4.65 L/kg

Remarks on result:

other: lab (sediment and pore water)

Phase system:

solids-water in sediment

Type:

log Kp

Value:

5.24 L/kg

Remarks on result:

other: field (sediment and pore water)

Sneller et al. stated, that the differences between the laboratory and the field derived data are probably due to disturbance and subsequent oxidation of the sediments in the laboratory experiments, causing relatively high concentrations in the pore water. In addition, increased decay of organic material in the disturbed sediments, involving reduction-processes, may contribute to release of REEs from sediment. For these reasons, field derived partition coefficients are preferred over laboratory derived values for calculation of MACs (maximum acceptable concentrations).

Furthermore, when evaluating the partitioning data one must keep in mind that pH, the presence of negative counterions and the concentration of dissolved organic carbon (DOC) in the (pore-) water strongly influence the concentration of REEs in solution. When pH, DOC concentrations and negative counterion concentrations are high, a large part of the total dissolved REE concentrations may not represent ´true´ partitioning.

Conclusions:

In this study, adsorption of Lu to sediment was evaluated by determining Lu in sediment, pore water, and surface water sampled in the field and after 10 days of using sediment/water samples in a study in the laboratory. The obtained log Kp sediment values were 5.30 and 5.87 L/kg when based on sediment and surface water concentrations in laboratory and field, respectively, and 4.65 and 5.24 L/kg when based on sediment and pore water concentrations in laboratory and field, respectively.

Description of key information

In total, twelve studies were selected as useful for covering the adsorption/desorption endpoint using a weight of evidence approach. Data were available for sediment, suspended matter and soil. The following final key values were retained: a log Kp of 5.11 for sediment-water, a log Kp of 3.72 for soil-water, and a log Kp of 5.20 for suspended matter-water.

Key value for chemical safety assessment

Other adsorption coefficients

Type:

other: log Kp sediment-water

Value in L/kg:

5.11

Other adsorption coefficients

Type:

other: log Kp soil-water

Value in L/kg:

3.72

Other adsorption coefficients

Type:

other: log Kp suspended matter-water

Value in L/kg:

5.2

Additional information

In total, twelve studies were selected as useful for covering the adsorption/desorption endpoint using a weight of evidence approach. Data were available for sediment, suspended matter and soil and will be further discussed below.  

For suspended matter, five studies were identified as useful. In the study of Censi et al. (2005), samples of suspended matter and (filtered) seawater were taken from various sampling sites in the western Gulf of Thailand and analysed for lutetium. Log Kp suspended matter-water values were calculated from the results obtained for paired samples and ranged between 5.09 and 6.58, the mean being 5.99. In a similar study by Censi et al. (2004), samples of suspended matter and (filtered) seawater were taken from two sampling locations in the Ionian Sea and three sampling locations in the Strait of Sicily. Based on the results from this study, log Kp values were calculated ranging from 3.66 to 5.10, the mean being 4.04. Moermond et al. (2001) determined lutetium concentration in surface water and suspended matter samples from six locations along the Rhine-Meuse estuary (the Netherlands). The log Kp value calculated based on the results of this study was 5.76. Zhang et al. (1998) took samples of suspended matter and (filtered) seawater from 8 sampling sites in the Yangtze river and analysed the samples for lutetium. Log Kp suspended matter-water values were calculated from the results obtained for paired samples and ranged between 4.82 and 5.12, the mean being 5.02. Finally, in the study by Kumblad and Bradshaw (2008), water and suspended matter samples were taken in the Forsmark area, Baltic Sea, and analysed for lutetium. The log Kp suspended matter-water was reported to be 4.0, using the detection limit as aquatic lutetium concentration since lutetium was not detectable in the water phase. Therefore, the latter value was not taken into account for calculation of the key log Kp suspended matter-water. Because there is a limited amount of studies included in the weight of evidence approach for suspended matter, the arithmetic mean was calculated of the (arithmetic) mean values from Moermond et al. (2001), Censi et al. (2004, 2005) and Zhang et al. (1998), resulting in an average log Kp value of 5.20, which is considered as the key value for characterising the distribution of lutetium between suspended matter and water.  

For sediment, eight studies were included in the weight of evidence approach. Based on lutetium concentrations measured by Moermond et al. (2001) in sediment, surface water and pore water samples taken from six locations along the Rhine-Meuse estuary (the Netherlands), log Kp values could be calculated ranging from 4.67 to 5.60. Sneller et al. (2000) reported log Kp values obtained by Stronkhorst and Yland (1998) of 4.65 to 5.87 for samples taken from the field and a laboratory study using field samples. More specifically, values of 5.30 to 5.87 were obtained for sediment-surface water and 4.65 to 5.24 for sediment-pore water. In the study by Weltje et al. (2002), sediment, and pore water samples were taken at five locations in The Netherlands in the Rhine-Meuse catchment. log Kp sediment-pore water values were reported (in figures) to range from 4.85 to 5.10. Marcussen et al. (2008) sampled sediment and pore water along two rivers receiving wastewater from Hanoi, Vietnam. Log Kp sediment-pore water values were reported to be higher than 4.89. However, reliability is restricted, because the pore water concentrations were below the limit of detection (resulting in unbound log Kp values). Moreover, it is reported in the publication that log Kp values may have been overestimated because they may represent both sorption and precipitation processes. Therefore, the unbound log Kp value is not taken into account for calculation of a key log Kp value for sediment-water. In the study by Kumblad and Bradshaw (2008), water, sediment, and pore water samples were taken in the Forsmark area, Baltic Sea, and analysed for lutetium. The log Kp sediment-pore water for the upper sediment layer (0-3 cm) was determined to be 2.83. This value was also excluded from the calculation of the key value as the lutetium concentrations in pore water were also below the limit of detection in this study. In the study of Takata et al. (2010), samples of sediment and water were taken from 15 sampling stations in 4 Japanese estuaria and analysed for lutetium. Log Kp values ranged from 5.52 to 6.39, the mean being 6.06. Chen et al. (1996) performed a multitracer experiment to investigate the adsorptive behaviour of lutetium and other lanthanides to marine sediments and obtained log Kp values for lutetium for deep-sea and near-shore sediment in artificial seawater of 5.41 and 5.0, respectively. Finally, Zhang et al. (1998) sampled sediment and (filtered) seawater at 8 sampling sites in the Yangtze river and analysed the samples for lutetium. Log Kp sediment-water values were calculated from the results obtained for paired samples and ranged between 4.80 and 5.11, the mean being 5.01. To determine a final key value, a single average (arithmetic mean) log Kp value was retained for each study. Pore water-based and surface water-based data were however not lumped, individual average values (arithmetic mean) were retained for this. The 10th, 50th and 90th percentile of the retained values was 4.94, 5.11 and 5.75, respectively. The median of 5.11 was taken as key log Kp for sediment-water partitioning of lutetium.  

   

For soil, two studies were identified as useful. Based on data from Du et al. (1998), in which adsorption of lutetium was investigated using cultivated Chinese soil and radiolabeled lutetium, a log Kp of 3.73 could be obtained. This study also indicated that lutetium sorption is rather determined by the presence of oxides and silicate clays than by CaCO3 and organic matter. Tao et al. (2000) performed experiments with a calcareous soil and a red earth and obtained log Kp values of 3.71 and 3.70, respectively, for these soils. The value for calcareous soil was not taken into account for calculation of the key log Kp soil-water value because it was estimated from the minimum detectable activity. Due to the limited availability of studies on the partitioning of lutetium in a soil-water system, the final key value was calculated as the average (arithmetic mean) log Kp value of the two remaining values from Du et al. (1998) and Tao et al. (2000), yielding a key log Kp soil-water of 3.72.