Abstract
Contact flocculation-filtration of humic dispersions with alum in medium grain (0.62 mm) sand gave short runs to breakthrough, while in coarse (1.2 mm) media clarification was inefficient. Alum with cationic polymer gave in coarse media acceptable runs, but shorter then for mineral dispersions. Analysis of results by parameters of existing filtration models showed that using the Ives-Iwasaki model and plotting filtration coefficient λ vs specific deposit σ gave different λmax for different polymer dose, plot of λmax vs dose goes through maximum at optimum dose. Plotting the cube root of headloss vs square root of specific deposit gave a straight line corresponding to Shektman formula. Analysis by Adin-Rebhun model showed that for contact flocculation-filtration humic dispersions attachment coefficient k1 was similar to, detachment k2 was many fold higher then and theoretical maximum mass capacity much lower then in case of mineral dispersions. Calculations showed that the solid content and the density of alumo-organic deposits in bed are much lower than of alumo-mineral deposits. Polymers and minerals increase the solid content, the density of deposits and the mass capacity of filter beds.
Original language | English |
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Pages (from-to) | 963-970 |
Number of pages | 8 |
Journal | Water Research |
Volume | 18 |
Issue number | 8 |
DOIs | |
State | Published - 1984 |
Externally published | Yes |
Keywords
- bed capacity
- breakthrough
- contact filtration
- deposit density
- filtration coefficients
- humic substances
- polyelectrolytes