Pentasodium (carboxylatomethyl)iminobis(ethylenenitrilo)tetraacetate

Monitoring data

Administrative data

Endpoint:

monitoring data

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1997

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study well documented, meets generally accepted scientific principles, acceptable for assessment

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Materials and methods

Principles of method if other than guideline:

Method: other

GLP compliance:

no

Type of measurement:

concentration at contaminated site

Media:

surface water

Test material

Test material information

Constituent 1

Reference substance name:

N-carboxymethyliminobis(ethylenenitrilo)tetra(acetic acid)

EC Number:

200-652-8

EC Name:

N-carboxymethyliminobis(ethylenenitrilo)tetra(acetic acid)

Cas Number:

67-43-6

IUPAC Name:

N,N-bis{2-[bis(carboxymethyl)amino]ethyl}glycine

Constituent 2

Reference substance name:

DTPA acid

IUPAC Name:

DTPA acid

Details on test material:

- Name of test material (as cited in study report): EDTA and DTPA

Study design

Details on sampling:

Two mills, one pulp mill localized at a fresh water lake and one pulp and paper mill at a brackish water were investigated, both mills were using bleaching technologies with EDTA and DTPA as complexing agents. Samples were collected at the discharge point and along a gradient in the receiving waters at two occasions: summer at solstice and winter with low light intensity. Samples were taken from surface, an intermediate depth and bottom water.

The samples collected in the receiving waters, were taken with a Ruttner sampler from a boat or from ice. The samples were immediately transferred to precleaned light impermeable polyethylene bottles to avoid photochemical degradation of the analytes. The samples for analyses of the complexing agents were acidified to pH 2.5 and stored in darkness at 4 °C until analysed.

Samples from three lakes (uncontaminated) were included as natural blind samples.

Results and discussion

Details on results:

It was possible to detect the used complexing agents and their first degradation products in the receiving waters in the vicinity of investigated mills. Two degradation products of DTPA were tentatively identified in mill effluent as two isomers of diethylenetriaminetetraacetic acid with the aid of GC-MS. The concentrations of DTPA and NTA diminished quickly and could only be detected a few kilometres from the discharge point. DTPA seemed to be more susceptible to degradation as compared to EDTA. EDTA was conclusively detected at low µg/l levels in Lake Vattern and sub-µg/1 levels in Aland Sea at distances far (≥ 45 km) from the investigated mills. A fraction of discharged EDTA but probably not DTPA was recalcitrant in the receiving waters. The contribution of complexing agents (NTA, EDTA) from municipal sewage plants was negligible in comparison with that discharged from the mills. The concentrations of EDTA and DTPA in the receiving waters were generally higher in winter than in sum

Any other information on results incl. tables

none

Applicant's summary and conclusion

Conclusions:

It was possible to detect the used complexing agents and their first degradation products in the receiving waters in the vicinity of investigated mills. Two degradation products of DTPA were tentatively identified in mill effluent as two isomers of diethylenetriaminetetraacetic acid with the aid of GC-MS. The concentrations of DTPA and NTA diminished quickly and could only be detected a few kilometres from the discharge point. DTPA seemed to be more susceptible to degradation as compared to EDTA. EDTA was conclusively detected at low µg/l levels in Lake Vattern and sub-µg/1 levels in Aland Sea at distances far (≥ 45 km) from the investigated mills. A fraction of discharged EDTA but probably not DTPA was recalcitrant in the receiving waters. The contribution of complexing agents (NTA, EDTA) from municipal sewage plants was negligible in comparison with that discharged from the mills. The concentrations of EDTA and DTPA in the receiving waters were generally higher in winter than in summer