León V M, López C, Lara-Martín P A, Prats D, Varó P, González-Mazo E
Department of Chemical Engineering, University of Alicante, P.O. Box 99, E-03008 Alicante, Spain.
Chemosphere. 2006 Aug;64(7):1157-66. doi: 10.1016/j.chemosphere.2005.11.045. Epub 2006 Jan 5.
The degradation of linear alkylbenzene sulfonates and their degradation intermediates (sulfophenylcarboxylic acids) has been characterized at 9 degrees C in an activated sludge pilot plant. After an adequate adaptation period (20 days), LAS primary degradation exceeds 99% and takes place preferentially for long alkyl chain homologues and external isomers. LAS homologues in the reactor are preferentially sorbed onto particulate matter, while sulfophenylcarboxylic acids (SPCs) are present predominantly in solution, due to their lower hydrophobicity. During the adaptation period the most abundant LAS biodegradation intermediates were long chain sulfophenylcarboxylic acids (SPCs) (C(9)-C(13)SPC). However once this system is fully adapted, the microorganisms are capable of degrading SPCs efficiently. SPCs with 7-9 carbon atoms in the carboxylic chain predominate due to their degradation being slower than for the rest of the SPCs. The presence of C(13)SPC confirms that LAS degradation in wastewater starts with a omega-oxidation on the alkylic chain. A preferential degradation of SPC isomers of the types 2phiC(n)SPC to 6phiC(n)SPC was also detected, as shown by the relatively higher SPC concentrations of the remaining ones.
在一个活性污泥中试装置中，研究了9℃下直链烷基苯磺酸盐及其降解中间体（磺基苯基羧酸）的降解特性。经过适当的适应期（20天）后，直链烷基苯磺酸盐的初级降解率超过99%，且长烷基链同系物和外消旋异构体优先发生降解。反应器中的直链烷基苯磺酸盐同系物优先吸附在颗粒物上，而磺基苯基羧酸由于疏水性较低，主要存在于溶液中。在适应期内，最丰富的直链烷基苯磺酸盐生物降解中间体是长链磺基苯基羧酸（C(9)-C(13)SPC）。然而，一旦该系统完全适应，微生物就能有效地降解磺基苯基羧酸。羧酸链中含有7-9个碳原子的磺基苯基羧酸占主导地位，因为它们的降解速度比其他磺基苯基羧酸慢。C(13)SPC的存在证实了废水中直链烷基苯磺酸盐的降解始于烷基链上的ω-氧化。还检测到2-苯基C(n)SPC类型的磺基苯基羧酸异构体相对于6-苯基C(n)SPC有优先降解，剩余的磺基苯基羧酸中其浓度相对较高就表明了这一点。
