THE ROLE OF PARTICLE-SIZE DISTRIBUTION IN THE PERFORMANCE AND MODELING OF FILTRATION

The paper examines the importance of size distribution of the influent suspension on the performance of deep bed filters and its significanc e with regard to modelling. Experiments were carried out under a varie ty of conditions using suspensions which were identical in every respe ct apart from their size distribution. The results indicate that the p resence of coarse particles does increase the removal of fine particle s. Deposition of fine particles leads to a greater headloss than depos ition of large particles. Changes in size distribution with time and d epth play an important role in determining the behaviour of a filter, and models of both removal and headloss development must take account of this.