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 = K2 S2 + K1 S + K0 , where v is the substrate consumption rate in the biodegradation process, S is the surfactant concentration in the medium and K2, K1, and Ko are kinetic constants . From this general expression, different simplified equations can be obtained (where Ko = 0 ; K2 and Ko = 0 ; K2 = 0 ; K2and K2 = 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.