1. Sand Filtration

2. Tipe: Slow sand filtration Rapid (gravity) sand filtration Rapid (pressure) sand filtration

3. Pengertian.? Sand filtration is a water purification process in which water is passed through a porous bed of filter medium – Slow sand filtration? – Rapid sand filtration?

5. Parameter desain SSF

6. Perbedaan? Slow sand filters are distinguished from rapid sand filters by the biologically active sand medium (including the Biofilm), and slow detention times. In a mature sand bed, a thin upper sand layer called a Schmutzedecke (Biofilm) forms. The Biofilm consists of biologically active microorganisms that break down organic matter while suspended inorganic matter is removed by straining. Rapid sand filters utilize primarily a physical removal process, are periodically backwashed for cleaning, and operate with long detention times. Slow sand filters are cleaned by periodically scraping the existing Biofilm.

7. RAPID SAND FILTERSLOW SAND FILTER Effective size: 0.35-0.50 mm Uniformity coefficient: >1.3/1.7 Filtration Rate : ~ 5 m 3 /m 2.jam Effective size: 0.15-0.35 mm Uniformity coefficient: 2-3 Filtration Rate : 0.1-0.2 m 3 /m 2.jam

8. Operasi

9. Mekasnisme proses.. 1.Mechanical, Phisical 2.Biological Lapisan Biofilm

10. Backwash. When is Backwashing Needed? The head loss is so high that the filter no longer produces water at the desired rate; (Filter Mampet) Floc starts to break through the filter and the turbidity in the filter effluent increases; (Effluent keruh)

11. BackWash

12. Expansion area = 20-50 % dari ketinggian bed filter