1. NATURAL WASTEWATER TREATMENT  Pollutant removal by minimal energy utilisation and chemicals  Usage of natural processes (natural resources)  Low cost technology

2. Advantages: –Environmental friendly –Low construction, operation and maintenance costs –Low energy demand –No special skills are required for the operation –Acceptable operation among wide range of conditions (loads, etc.) –Can be constructed on otherwise „useless” areas –aesthetics –Able to treat diffuse pollutants

3. Disadvantages: –Large area requirement (long residence time) –Special requirements (topography, soil type) –Seasonal change in pollutant removal efficiency –Start-up period can be long –Construction problems can be hidden for long time

4. TERRESTRIAL SYSTEMS irrigation slow rate infiltration rapid infiltration root zone system (reed beds, subsurface flow wetlands)

5. AQUATIC SYSTEMS ponds, lagoons anaerobic facultative (aerobic-anaerobic) aerobic aerated fish ponds floating plant system free water surface wetland overland flow

6. RAPID INFILTRATION

8. SLOW RATE INFILTRARTION wastewater evaporation infiltration

9. POPLAR IRRIGATION

10. REED BEDS

11. REED BED

12. FREE-FLOATING PLANTS

13. OPERATIONAL PARAMETERS 0,14-1,6irrigation 0,6-3,0303-18925 Slow rate filtration 23-56303-48000 Rapid infiltration 5,1-11,7(8,2)1,4-22,3(7)337-4147 Free surface wetland 19,1(3,1)2,4(10)49-2248Free-floating 0,9-23,0(5)0,87-26,0(7,8)1-200 Reed bed SPECIFIC SURFACE m 2 /pe HIHYDRAULIC LOAD cm/dayCAPACITY m 3 /day TYPE

14. REMOVAL EFFICIENCIES 699380 Rapid infiltration 50(15-81)50(12-65)80(60-93)80(51-89) Free surface wetland 50(16-67)40(14-72)80(20-95)80(10-94) Free floating plant 40(11-94)40(10-88)80(60-98)80(51-95) Reed bed TNTPTSS BOd 5 Type