This research is focusing on study of the effect of foulant interaction between surfactant, reactive dye (anionic dye), and effluent organic matters (EfOMs) in textile wastewater on fouling of reverse osmosis (RO) membrane. The experimentation and modeling reveal that surfactant yielded highest flux decline and the change in permeate flux was influenced by the presence of foulant monomers and aggregates formed between the foulants. When the surfactant concentration was maintaining lower than the critical micelle concentration (CMC), permeate flux was influenced by its concentration. Nevertheless, an increase in surfactant concentration above CMC did not yield further flux decline because of the effect of micellisation. The aggregates composed EfOMs increased permeate flux comparing with the wastewater containing single foulant. The perceptible aggregation of dye and non-ionic surfactant increased permeate flux comparing with the wastewater containing single non-ionic surfactant. In the case of anionic surfactant, the repulsive force between anionic charge of dye and anionic surfactant resisted their aggregation therefore, the additional dye did not increased permeate flux comparing with wastewater containing single anionic surfactant. A mathematical model derived from the deposition of aggregates and monomers on the membrane surface could be used for prediction of RO permeate flux. (C) 2009 Elsevier B.V. All rights reserved.