The adhesion and detachment of spherical glass particles from a flat glass surface are studied experimentally and theoretically. Adhesion is found to be strongly dependent on pH through modification of surface characteristics as well as through the imposition of electrostatic repulsion, which may prevent close approach of the adhering surfaces. A theoretical analysis of the detachment mechanism for smooth and rough surfaces is also presented. The experimentally found dependence of hydrodynamic forces on particle size, corroborated by the theoretical analysis, suggests that a rolling mechanism is responsible for detachment and that roughness at the submicroscopic level plays a decisive role.