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Environmental fate & pathways

Hydrolysis

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Administrative data

Endpoint:
hydrolysis
Remarks:
The substance is hydrolytically unstable (half-life less than 12 hours)
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Basische Aluminiumsalze - kondensierte Phasen feranderlicher Zusammenzetzung
Author:
Dobrev Chr., D. Trendafelov, P. Dobreva
Year:
1981
Bibliographic source:
Freib . Forsch .-H. A 653 .Hrsg .: Rektor der Bergakademie Freiberg Leipzig: VEB Deutscher Verlag fur Grundstoffindustrie 1981
Reference Type:
publication
Title:
Unnamed
Year:
1983
Reference Type:
other company data
Title:
Unnamed
Year:
1996
Report date:
1996

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)
Deviations:
yes
Remarks:
The substance is hydrolytically unstable (half-life less than 12 hours)
Principles of method if other than guideline:
CFS10Al is the product of partial hydrolysis of Al:
BASICITY
In an acid (alkaline) environment, aluminum is thermodynamically unstable and transitions into a water solution. Because of the significant energy of hydration of Al3+ ions in the water solution, they turn into hexaaquaaluminum ions: Al(H2O)63+. Polycondensation results in the formation of various poly nuclear aquahydroxyaluminium complex ions:

x[Al(H2O)6]3+ = [Alx(OH)y(H2O)2(3x-y)](3x-y)+ +yH3O+

The energy level diagram of Al2O3-HA-H2O
(where HA-mineral acid) type Systems is plotted based on equilibrium data of the dissociation of aquahydroxyaluminium cations and the values of
electroconductivity activation energy and viscosity. The driving force of condensation processes of aluminium- oxygen octahedra is
expressed by the thermodynamic potentials per mole of water liberated during condensation. The simultaneous existence of various poly-condensation products in aqueous solutions of basic aluminium salts, the discrepancies in literature data available, as well as some peculiarities of the Systems discussed are explained by the small driving force and the presence of product transition activation energy.
The low energy level of aluminum compounds and the closeness of their thermodynamic potentials is the basis of their diversity. This is also the reason for many contradictory results in the study of aluminum compounds.
The substance is hydrolytically unstable (half-life less than 12 hours)
Например при използуването на алуминиев сулфат като коагулант за вода разреждането е до ~10 mg/dm3, скоростните константи на хидролиза и полимеризация са съответно 10^10 s-1 и 10^2—10^3 s-1, т. е. практически процесите протичат мигновено, а продуктите са с произведение на разтворимост 10^23—10^33.

GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
Aluminum chloride hydroxide sulfate
EC Number:
254-400-7
EC Name:
Aluminum chloride hydroxide sulfate
Cas Number:
39290-78-3
Molecular formula:
generic molecular formula Al(OH)xCl(3-x-2y)(SO4)y, where 0.6
IUPAC Name:
dialuminium(3+) dichloride dihydroxide sulfate
Test material form:
liquid: viscous
Details on test material:
Macrocomponents: %(w/w): Al2O3 - 18.78; HCl - 9.07; H2SO4 - 0.9; H2O - 69.59.
Specific details on test material used for the study:
Al2O3.1,4HCl.0,05H2SO4.21,4H2O or Al(OH)2,25Cl0,7(SO4)0,025 ; a=2.25; basicity 75%
Al2O3 18.78 %
HCl 9.41 %
H2SO4 0.90 %
H2O 70.91 %
Radiolabelling:
no

Results and discussion

Transformation products:
yes
Identity of transformation products
No.:
#1
Reference
Reference substance name:
Unnamed
Inventory number:
InventoryMultipleMappingImpl [inventoryEntryValue=EC 244-492-7]
CAS number:
21645-51-2
Molecular formula:
AlH3O3
Total recovery of test substance (in %)
% Recovery:
> 80 - < 100
pH:
7.5
Temp.:
10 °C
Dissipation DT50 of parent compound
Key result
pH:
7.5
Temp.:
10 °C
Hydrolysis rate constant:
>= 100 - < 1 000 s-1

Applicant's summary and conclusion

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