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Ecotoxicological information

Toxicity to aquatic plants other than algae

Administrative data

Endpoint:
toxicity to aquatic plants other than algae
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Not a guideline study

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
2004

Materials and methods

Principles of method if other than guideline:
Different types of solid waste from KRAFT pulping process were mixed to different types of soil/substrate, and seed from different types of plants were planted in the mixtures in order to measure the effects of the dreg addition to germination and growth (height or fresh weight) of the plants.
GLP compliance:
not specified

Test material

Constituent 1
Reference substance name:
Automatically generated during migration to IUCLID 6, no data available
IUPAC Name:
Automatically generated during migration to IUCLID 6, no data available
Details on test material:
Solid residues from Kraft pulping process: ashes, primary sludge, fly-ash, dregs, grits, and brown stock rejects.

Sampling and analysis

Analytical monitoring:
no

Test solutions

Details on test solutions:
Hoagland's Medium was used in combination with the different residual materials in ratio 2,5 parts residue to 7,5 parts HM.

Test organisms

Test organisms (species):
Lemna minor
Details on test organisms:
No data other than the name of the species was given.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
50 d

Test conditions

Hardness:
No data.
Test temperature:
23-25 °C
pH:
Control: 4,80 Control, dregs: 8,81, ash: 9,16, fly-ash: 7,96, p.sludge: 8,10, b.rejects: 7,18, grits: 10,25
Dissolved oxygen:
No data
Salinity:
No data
Nominal and measured concentrations:
No data
Details on test conditions:
The duckweed fronds were cultivated In vitro in growth chambers provided with fluorescent lamps (Philips TLD 36W/54) with a photon flux of 45µmol/m2/s.
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
50 d
Dose descriptor:
other: number of fronds/flask
Effect conc.:
25 other: % of the total substrate volume
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
frond number
Remarks on result:
other: control: 295,0 fronds
Duration:
50 d
Dose descriptor:
other: number of fronds/flask
Effect conc.:
25 other: % of the total substrate volume
Nominal / measured:
not specified
Conc. based on:
test mat.
Basis for effect:
frond number
Remarks on result:
other: Dregs: 284,5 fronds
Duration:
50 d
Dose descriptor:
other: number of fronds/flask
Effect conc.:
25 other: % of the total substrate volume
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
frond number
Remarks on result:
other: Ash: 128,5 fronds
Duration:
50 d
Dose descriptor:
other: number of fronds/flask
Effect conc.:
25 other: % of the total substrate volume
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
frond number
Remarks on result:
other: Fly-ash: 422 fronds
Duration:
50 d
Dose descriptor:
other: % of the total substrate volume
Effect conc.:
25
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
frond number
Remarks on result:
other: P.sludge: 363,3 fronds
Duration:
50 d
Dose descriptor:
other: number of fronds/flask
Effect conc.:
25 other: % of the total substrate volume
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
frond number
Remarks on result:
other: B.rejects 204,0 fronds
Duration:
50 d
Dose descriptor:
other: total number of fronds/flask
Effect conc.:
25 other: % of the total substrate volume
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
frond number
Remarks on result:
other: Grits: 10,5 fronds
Details on results:
For duckweed, a higher number of fronds and fresh weight were found in the presence of fly-ash and primary sludge in spite of the high pH values of the media (initial pH close to 8), as compared to plants developed in Hoagland's nutrient solution alone 8pH 4,8), after a 50-day culture period. The results are presented in table I.In contrast, ash, brown stock rejects, and especially grits strongly inhibited growth, causing chlorosis and early death of new fronds. It is assumed that other components present in these residues can account for these effects, besides the high pH levels.

Any other information on results incl. tables

Table I. Growth responses of duckweed (Lemna minor) developing in the presence of cellulose mill residues.

Residue (Waste:HMaratio)

Fronds/Flask

Fresh weight (mg)

pH

Control (0:10)

295,0

365

4,80

Dregs (2,5:7,5)

284,5

399

8,81

Ash (2,5:7,5)

128,5

198

9,16

Fly-ash (2,5:7,5)

355,6

422

7,96

Primary sludge(2,5:7,5)

363,3

710,3

8,10

Brown rejects (2,5:7,5)

204,0

344

7,18

Grits (2,5:7,5)

10,5

4,3

10,25

aHoagland’s Medium

Applicant's summary and conclusion

Conclusions:
In the presence of fly-ash and primary sludge the growth of duckweed was enhanced. Ash, brown stocke rejects and grits srtongly inhibited growth and caused early death and chlorosis in the fronds. It is assumed that other components present in these residues can account for this effect besides the high pH levels.

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