Study on Macroscopic Aggregation of Silica Suspensions and Sewage

(SiO2)n aggregates flocculated with Al and Fe coagulants were studied. An advanced photographic method for measuring the size and velocity of the aggregates was applied. Fractal dimension D = 1.64-1.95 for 1000 measured aggregates at mean determination coefficient &rmacr;2 = 0.940 was calculated. A high variety of "solid mass" contributions (a relative smc ranged from 1 to 18.5) to the total mass of the average sludge were ascertained. Some implications of the process of aggregations studied were supplied. Fractal dimension was recognized as a powerful tool in any aggregate approach, being sensitive enough to distinguish many subtle varieties.