Rastlinske čistilne naprave

1. SludgeDryingReedBeds Rastlinske čistilne naprave »Ekoremediacije – učinkovite in varčne metode za čiščenje odpadne vode in obdelavo komunalnega mulja« Workshop “YOUTH FOR ENVIRONMENT“ Introduction to Ecoremediations Vlora, 7.4.2016

2. What is sludge? Any solid, semi-solid, or liquid residue removed during the treatment of municipal waste water or domestic sewage. • Sewage sludge includes all types of sludge originating from: • Sewage treatment plants • Septic tanks • Small collection tanks/manholes and stormwater • Other collection tanks with untreated sewage

3. Sludgetypes

4. Sludgecharacteristics • 95.5 % ofwater, otherorganicandinorganicparticles • No smell • Contentofpathogenicmicroorganisms • It may contain heavy metals and mikropolutante

5. Sludgetreatmentpossibilities Mechanicaltreatment Biologicaltreatment

6. Sludge treatment reed bed for sludge dewatering and mineralization Land intensive technique to dewater, stabilize and mineralize sludge from wastewater treatments Water-solid separation occurs by the combination of gravity, filtration, plants and biochemical processes in the beds Final disposal on agriculture or green areas without further stabilization.

7. Use of SDRB WWTP: - activatedsludge (0,5 – 2 % SS) - primarysludge (1 – 5 % SS) Sludgeflow SDRB - Operationalcycle ~ 10 let - Lifetime > 30 years Leachate SludgedisposalČ - Agriculture - Greenareas Emptyingafter 10 years

8. H2O Evapotranspiration Processes Aeration O2 Stabilisation and mineralisation Filter layer Sludge distribution Leachate • Aerobic digestion and mineralisation • Plant uptake • Micoorganisms • Drainage and sludge drying

9. Role ofthereeds Growth of root-system keep filter ‘open’ so water can drain Wind-induced movements of plant stems create cracks in the sludge surface Plants take up and transpire capillary bound water from the sludge Plants transport oxygen to the sludge Plants may release organic compounds from the roots that stimulate bacteria

10. SDRB construction • Amoun of treated sludge 80 do 150 g SS/d PE • Filter layer area 0,25 – 0,7 m2/PE • Chemical composition • Proper assembly and installation of the filter layer • Proper drainage and distribution pipes • Ptoper planting

11. Costs • Before 2008, the possibility of disposal of sludge at landfills for non-hazardous waste • 50 % • 2008 - EU Directive Costs!!! 30 – 50 % of WWTP operationalcosts • Sludge treatment • Transport • Incenaration in Avstriji: 150 – 500 €/T (SS) (Urek; 2011) SDRB: Return of investment in 6-8 years!!!

12. Advantages • VOLUME REDUCTION • Final DM content25 - 35 % • Volumereduction95 % • Mineralisation30 % lessoforganicmatter • NO CHEMICALS • No floculants, polymers

13. Advantages • ENERGY ASPECT • Energysavings20 - 60 % • Onlypumpsandconstrolsystem • ECOLOGICAL ASPECT • No smell • Healthyworkenvironment • Smaller CO2 impact – greentechnology!

14. Advantages • STRATEGIES • EU guidelinessuggestuseofmunicipalsludgeforagriculture • LOWER INVESTMENT AND BETTER WWTP EFFICIENCY • No sludgethickening • No oversized WWTP (do 15 %)

15. Implementation • Singlehouseholds • Settlements • Turisticfacilities • Towns • Industrialplants

16. Wordwide cases • Sludge treatment from septic tanks • Negreplisse (France) 131 T SS/l

17. Activated sludge treatment: • Dellach am Drautal (Avstrija); 6.800 PE • Rudkøbing (Denmark); 14.000 PE