The influence of the structure of flocculent aggregates on the course and efficiency of separation processes

The project is focused on researching the influence of: (1) Chemical composition and concentration of impurities, (2) agitation intensity, its duration and distribution of a velocity field in the stirred volume of water on the properties of flocculent aggregates; (3) The physical factors that are influencing the inner arrangement of particles in aggregates, size, size-distribution, density and resistance to fragmentation of aggregates; (4) The selection of such characteristics of aggregates, that can be used for evaluation and comparison of the conditions of formation of aggregates in jar tests and through-flow reactors. Water from different natural surface sources will be examined. The Al- and Fe-reagents will be used as the destabilisation reagents and cationic polyelectrolytes as the aggregation reagents. The formation of aggregates will také place in reactor (a) fitted with a paddle type stirrer and in an annular space between two concentric cylinders with the inner one revolving. The properties of aggregates that influence their separability will be determined in the through-flow pilot plants, in which agitation will be provided by: (a) paddle type stirrers, (b) perforated partitions, (c) fluidised layer of granular material and (d) concentric cylinder. The validity of criterion Ca = G.T = const. will also be experimentally verified.