Wastewater produced in the form of an o/w emulsion is difficult to treat properly because of its complex behavior. To acquire information for the optimization of emulsion controlling processes, the interfacial features of emulsion systems have been investigated in this work. The surface tension is found to decrease as the oil content is increased, and contact angle is influenced by the hydrophobicity of the substrate. The work of adhesion for substrates with different degrees of hydrophobicity has been estimated from the contact angle and surface tension. Temperature and pH have a significant influence on the turbidity and surface tension, and it is observed that electrophoretic characteristics of oil droplets are closely related with turbidity. Also, effects of inorganic salts and surfactants on the electrokinetic properties of emulsions have been considered, and the influence of coagulant on the stability is discussed through the calculation of potential energy of interaction between oil droplets. Adsorption and electrocoagulation processes have been attempted under various conditions in order to examine the practical treatment efficiencies of emulsion in relation to its interfacial characteristics.