But if the gdl easy enough to remove physical and mechanical methods (sedimentation and filtration), then aggregate-stable colloids require physical and chemical methods – namely, coagulation, in which the destabilization of the dispersed system with consolidation and the continued fallout of flakes (floccules). The resulting solid phase separated from the water in the clarifiers and clarifying filters. In practice, as a coagulant used poligidraty aluminum salts and iron, for example, or polialyumogidrohlorid polialyumogidrosulfat or poligidrat iron sulfate (II). The latter reagent is used for the combined processes of coagulation and calcification. The process of clarification by coagulation – a complex physicochemical phenomenon whose success depends on the mass parameters. None However, there are four main factors that determine the speed and quality of the reaction.
1. Flow rate. Since the depth of deterministic time education and consolidation floccules should consider that the flow regime can significantly influence the emerging primary loose flakes. In the limit, they may even collapse. Therefore, the rate of water flow in the reaction zone and advance shall not exceed 1-1,5 mm / sec.
2. pH. In Due to the fact that the speed and depth of coagulant hydrolysis determines the acidity of the medium, it should be a given for this reagent parameters. For example, for aluminum sulfate empirical value of the optimal pH is within 5,5-7,5. In more acidic (pH 4,5) among the hydrolysis of the reagent does not occur, but in more alkaline (over 8) resulting aluminum hydroxide, due to amphoteric metal dissociates as the acid, resulting in efficiency of the process falls.