The main types of separation processes used in the treatment of waste streams. Phase separation - basic principles of phase separation. Thermal operations. Evaporation. Condensation. Drying of materials. Mechanical separation processes and equipment for the mechanical separation (rotary filters, centrifuges, grinders, sedimentation tanks). Equilibrium separation processes - phase equilibrium. Equipment for the equilibrium phase separation (absorption, distillation, adsorption, ion exchange, extraction and crystallization). Speed separation processes - membrane separation (equipment for micro and ultrafiltration, reverse osmosis, dialysis). Criteria for the selection of appropriate separation processes. Order of the individual units in the formation of the optimal separation process. Single-stage and multi-stage separation processes.