MATHEMATICAL-MODELING OF PARTICLE-SIZE DISTRIBUTION IN SECONDARY EFFLUENT FILTRATION

Analysis of various types of secondary effluents revealed a broad rang e of particle sizes, suggesting that particle size distribution (PSD) should be taken into consideration in deep-bed filtration calculations rather than concentrating exclusively on process parameters. A PSD fu nction is shown to be a more effective and reliable index than the con ventional ''mean'' particle diameter. The power law function was found to express effluent PSD well; experimental data confirmed its validit y. The application of this function is demonstrated using a recent fil tration model based on the Kozeny equation. Prediction of the head los s, based on influent PSD function parameters alone, is possible in the filter working phase, and an equation for this aim is developed.