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/34) BIODEGRADABILITY IN SEA WATER OF LINEAR ALKYLBENZENE SULPHONATES (LAS) AND NONYLPHENOL ETHOXYLATES (NPEOs).

Sibila-Lores, Miguel Angel¹, Riaza-Frutos, Abel¹, Manzano, Manuel¹, Quiroga, Jose Maria¹, Perales, Jose Antonio¹, ¹ Department of Chemical Engineering and Environmental Technology.Faculty of Marine and Environmental Sciences.University of Cádiz, 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 main world consumed surfactants, linear alkylbenzene sulphonates (LAS) and nonylphenol ethoxylates (NPEOs) are shown. The analysis of the surfactants were carried out by means of reversed phase high performance liquid chromatography (HPLC), and the biodegradation of the reference substrate (sodium benzoate) was followed analysing the total dissolved organic carbon concentration. The test media used was sea water from Cadiz Bay (Southwest of the Iberian Peninsula) amended with a standard inorganic nutrient solution. The results show that both linear alkylbenzene sulphonate and nonylphenol ethoxylates biodegrade primarily in accordance with logistic and first order kinetics models, respectively; with average half lives (t_1/2) of 6.15 ± 0.45 days (n=5, 95%) and lag periods (t_L) of 6.67 ± 0.6 days for linear alkylbenzene sulphonate and t_1/2 = 28.19 ±1.37 days (n=5, 95%) and lag periods of 5.08 ± 0.29 days for nonylphenol ethoxylates.

Key words: linear alkylbenzene sulphonates, Biodegradability, nonylphenol ethoxylates , sea water