1 IV. Wastewater Treatment Technologies Topic IV. 10. Wastewater Treatment Facilities with Attached Biomass - Trickling Filters: Kinds, Structures, Basic Technological Parameters Kinds of Trickling Filters I. According to the technological parameters §Low rate trickling filters §High rate trickling filters §Rotating disks II. According to the carrying material §Natural (gravel) §Plastics l Grains l Sheets

2 Wastewater Treatment Facilities with Attached Biomass Kinds of Trickling Filters III. According to the necessity of wastewater recirculation §With purified wastewater recirculation §Without purified wastewater recirculation IV. According to the the kind of biological processes §Aerobic l With natural circulation of air l With ventilators or blowers §Anaerobic V. According to the technological stages l One stage (single) l Two stages

3 Kinds of Trickling Filters Technological Schemes with Recirculation a - with purified wastewater recirculation б - with purified wastewater and secondary sludge recirculation b - with interim settling 1 - primary settling tank 2 - trickling filter 3 - secondary clarifier 4 - secondary sludge 5 - recirculating wastewater 6 - primary and secondary sludge

4 Kinds of Trickling Filters Scheme of Two Stage Trickling Filters 1 - primary sludge; 2 - first stage trickling filter; 3 - first stage secondary clarifier; 4 - second stage trickling filter; 5 - second stage secondary clarifier; 7 - recirculating purified wastewater; 8 - primary and secondary sludge

5 Trickling Filters Structures General Scheme of Trickling Filter (Round in Plane) 1 - biomass carrier; 2 - wall; 3 - drainage bottom; 4 - drainage collecting channel; 5 - jet wastewater distributing device; 6 - ventilation orifices

6 Trickling Filters Structures Jet Wastewater Distribution Device

7 Trickling Filters Structures Drainage Bottom of Trickling Filter a - bricks; б - arch drainage elements; b - concrete bar racks; г - drainage bottom supporting elements

8 Trickling Filters Structures Rotating Disks (Biodisks)

9 Trickling Filters Basic Technological Parameters q f - surface hydraulic load, m 3 /m 2.d q w - volume hydraulic load, m 3 /m 3.d OC - oxidizing capacity, gBOD 5 /m 3.d OL - organic load, gBOD 5 /m 3.d Q - wastewater design flowrate, m 3 /d W - trickling filter working volume, m 3 Q r - recirculating wastewater flowrate, m 3 /d n - recirculation ratio L 0 - influent BOD 5 concentration, g/m 3 L - effluent BOD 5 concentration, g/m 3 L mix - mixed wastewater BOD 5 concentration, g/m 3 F - trickling filter horizontal area, m 2