A PREDICTIVE NUMERICAL THERMODYNAMIC MODEL OF MIXED NONIONIC SURFACTANT SORPTION IN NATURAL SYSTEMS - 1 - MODEL FORMULATION AND SENSITIVITYANALYSIS

Because most commercially available surfactants consist of mixtures of surfactant components, an understanding of mixed surfactant sorption behavior in the presence of natural materials may be essential for opt imal design of surfactant-based industrial processes or environmental remediation applications. This paper presents a new predictive numeric al model of surfactant sorption which can be used to assess the sorpti on behavior of nonionic surfactant mixtures based on a minimal set of physically intuitive, measurable parameters. The model is based on a c hemical equilibrium formulation and can predict the sorption behavior of very broadly distributed mixtures containing 40 components or more. Formulation of the model is presented, and solution methods are discu ssed. The influence of model parameters on isotherm shape is examined, and application of the model to prediction of mixed sorption of a bin ary surfactant mixture is presented, An extension of the model which i ncludes multiple surface site types is discussed. (C) 1998 Academic Pr ess.