The process of pelleting flocculation, a further development of classical flocculation technology, is defined as a formation of wet pellets directly in a liquid medium. Apart from well described mechanisms of flocculation like perikinetic and orthokinetic flocculation, the mechanism responsible for the formation of dense agglomerates is the mechanical syneresis guaranteed by the appropriate reactor form. Upon the two established models in the literature: the series system and the parallel system, experiments were performed to simulate a layer-by-layer particle deposition on the so-called "mother seeds" conforming to the parallel system. The present paper deals with the results originating from laboratory scale experiments with model sludge, kaolin suspension. The layering process was conducted in the presence of different cationic flocculants and the resulting relationships with respect to their nature and to the applied energy level have been assessed. The achieved agglomerates exhibit an "onion like" structure with densities up to 1.42 g/cm(3) and solid matter content up to 48% after gravity dewatering. Thus generated sludge agglomerates reveal the optimisation potential for sludge treatment manifested by improved characteristics achieved during the conditioning. (c) 2005 Elsevier B.V. All rights reserved.