The design and operation of flocculation processes are discussed in the context of the specific requirements of dewatering systems such as sedimentation and filtration. Chemical conditions, reagent selection and process operating conditions are evaluated based on the fundamental mechanisms involved in particle destabilization and flee development. Opportunities for control of flee characteristics through appropriate process design are described. Specific requirements for different dewatering processes are discussed. (C) 2000 Elsevier Science B.V. All rights reserved.