This paper is concerned with effects that arise from the electric charge on the surface of porous colloidal particles. When an external disturbance is applied, for example a change in the concentration of the surrounding electrolyte or an applied electric field, a complicated interaction ensues between the electric field, the liquid pressure field and the ion concentration fields in these particles. In this paper we derive the governing equations for these electrokinetic interactions for a general pore geometry and particle shape, and we present a procedure for solving these equations in the case of a general binary electrolyte. As an illustration, we obtain a new result: a formula for the complex electrical conductivity spectrum of a dilute suspension of porous spheres. (C) 2019 Elsevier Inc. All rights reserved.