PARENT SESSION

1B+C Abiotic Transformations + Biodegradation
Poster Hall
8:30 AM - Monday, 28 April 2003
Chair: Peijnenburg, W.¹, ¹
Co-chair: Jafvert, C.T.², Gombar, V.K.³, ^{2 3}

(MOP/40) CHANGES IN THE HOMOLOGUES AND ISOMERS COMPOSITION DURING LINEAR ALKYLBENZENE SULPHONATE (LAS) BIODEGRADATION IN SEAWATER.

Perales, Jose Antonio¹, Manzano, Manuel Alejandro¹, Sales, Diego¹, Quiroga, Jose Maria¹, ¹ Environmental Technology Research Group. University of Cadiz, Puerto Real, Cadiz, Spain

ABSTRACT- The results of the application of the biodegradation test OPPTS 835.3160 -Biodegradability in sea water- proposed by USEPA to the most world consumed surfactant, linear alkylbenzene sulphonate (LAS) are shown. The analysis of the different homologues and the isomers of the surfactant used were carried out by means of high performance liquid chromatography (HPLC). The test media used was seawater from Cadiz Bay (Southwest of the Iberian Peninsula). The results obtained shows that both, half-life and lag time has a significative linear correlation with the alkyl chain length of the LAS homologues. This relation indicates that the longer homologues not only are those that begin to be biodegraded first but also at higher rates. Related to the isomeric composition, it was observed that as higher is the primary biodegradation percentage reached, higher is the proportion of internal isomers compared with the initial isomeric composition.

Key words: Surfactants, Biodegradation, Sea, LAS