Sodium Salts of (1-Hydroxyethylidene)bisphosphonic acid (1-2:1)

Phototransformation in water

Administrative data

Endpoint:

phototransformation in water

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Data source

Reference

Reference Type:

publication

Title:

Properties of Hydroxyethane Diphosphonate affecting its Environmental Fate: Degradability, Sludge Adsorption, Mobility in Soils, and Bioconcentration

Author:

Steber, J. and Wierich, P.

Year:

1986

Bibliographic source:

Chemosphere 15:7 (1986), 929-945

Materials and methods

Study type:

other: direct photodegradation plus subsequent biotic degradation

Principles of method if other than guideline:

Test in small outdoor basins (volume ca. 3 cubic metres, depth 1 m) filled with water from a reservoir (Verse-dam). Exposure of 14C-HEDP solutions in closed 100 ml test flasks at various depths of water. 14CO2 formed was subsequently trapped in ethanolamine by flushing the flasks with nitrogen (4 h; 1 l/h).  Thereafter, test solutions were inoculated and incubated in the dark ("post-incubation").

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Disodium dihydrogen (1-hydroxyethylidene)bisphosphonate

EC Number:

231-025-7

EC Name:

Disodium dihydrogen (1-hydroxyethylidene)bisphosphonate

Cas Number:

7414-83-7

Molecular formula:

C2H8O7P2.2Na

IUPAC Name:

disodium dihydrogen (1-hydroxyethane-1,1-diyl)bis(phosphonate)

Test material form:

not specified

Study design

Radiolabelling:

yes

Light source:

sunlight

Duration of test at given test condition

Initial conc. measured:

0.1 mg/L

Results and discussion

% Degradation

% Degradation 1

% Degr.:

>= 27 - <= 40

Sampling time:

11 d

Test condition:

Degradation during expsosure period following daylight exposure (June 1982) at depths between 10-100 cm in water (based on 14CO2 + 14C-biomass)

% Degradation 2

% Degr.:

>= 11 - <= 19

Sampling time:

11 d

Test condition:

Degradation during expsosure period following daylight exposure (September 1982) at depths between 10-100 cm in water (based on 14CO2 + 14C-biomass)

Any other information on results incl. tables

Degradation extent (14CO2 + 14C-biomass) in % of initial
radioactivity after exposure (incl. 2-week post-incubation
in the dark) was dependant on water depth and test period:

% degradation
water depth [cm] June (11 d) Sept. (11 d)
---------------------------------------------------
10 40 19
50 32 11
100 27 12
Dark 15 10