Biodegradation kinetics of surfactants in seawater

In this paper, a general kinetic model for degradation processes of surfactants is proposed. The model equation is v = K 2 S 2 + K 1 S + K 0 , where v is the substrate consumption rate in the biodegradation process, S is the surfactant concentration in the medium and K 2, K 1, and K o are kinetic constants . From this general expression, different simplified equations can be obtained (where K o = 0 ; K 2 and K o = 0 ; K 2 = 0 ; K 2and K 2 = 0), which are representative of the process for different operating conditions. This model was tested by measuring the degradation of two different surfactants (Sodium dodecyl benzene sulfonate, LAS; and Sodium dodecyl sulfate, DSNa) under two different temperatures (5 and 20°C). Values predicted by the model are close to experimental data obtained.