LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
the 5 th and 95 th percentile values. Therefore, the recalculated value provided
in the IUCLID HEDSET (Year 2000 data) was used above.
Reference: 1) ECETOC. 1993. Environmental hazard assessment of substances.
Technical Report No. 51, European Centre for Ecotoxicology and
Toxicology of Chemicals, Brussels.
2) BKH. 1993. The use of existing toxicity data for estimation of the
Maximum Tolerable Environmental Concentration of Linear Alkyl Benzene
Sulfonate, Part I: Main report; Part II: Data base. Study carried out for
ECOSOL, BKH Consulting Engineers, Delft, NL.
Reliability: 4 Not assignable because of uncertainty related to the input parameters.
3.4 MODE OF DEGRADATION IN ACTUAL USE
Remarks: Refer to other sections.
3.5 BIODEGRADATION
(a)
Type: aerobic [X]; anaerobic [ ]
Inoculum: adapted [ ]; non-adapted [X] Marl, East treatment plant (Germany)
Concentration: 10 mg/L
Medium: Semi-continuous activated sludge (SCAS)
Method: The Marl purification plant consists of a mechanical prepurifying area, two
parallel trickling filters of 800 m 3 volume each, and a stimulation plant of
106 m 3 volume, as well as mechanical final clarification. Samples were
collected at the inlet of the trickling filters and at the exit of the final clarifier.
Three-hour composite samples were taken for each analysis. The MBAS
procedure was used to quantify LAS concentrations. The specific method for
analyzing the homologues is reported in Wickbold 1964.
Results: Results of the percent removal by activated sludge for different alkyl chain
length homologues and phenyl positions are shown in the following table:
C10
C11
C12
C13
a Not analytically separable
Phenyl Position % Degradation
5
4
3
2
6
5
4
3
2
6
5
4
3
2
7,6 a
5
4
3
2
52
68
88
UNEP PUBLICATIONS 155
92
58
72
89
93
94
81
92
94
95
95
92
94
95
96
96