Municipal wastewater purification by phytotreatment and water recovery

1. Municipal wastewater purification by phytotreatment and water recovery by prof. Paolo Broglio ( M.Sc. Ph.D ) Scientific Director of Ecologia Applicata Company and Environmental Director of ESAE

2. PHYTOWATERPURIFICATION The PHYTOWATERPURIFICATION is: A broad and natural method realised by designing specific systems in order to reproduce a natural auto-depurative processes in a monitored environment Ideal application: up to 100 people Possible application: up to 500 people

3. PHYTOWATERPURIFICATION Advantages Low management and maintenance costs Depurative performances compatible with traditional plants Low visual impact Disadvantages Require considerable space per inhabitant Depend upon environmental conditions (temperature, pH)

4. PHYTOWATERPURIFICATION Fields of application Secondary waste water treatment (biological) “…For all settlements with a population ranging between 50 and 2000 people, it is recommended the application of natural depuration technologies, such as aerobic lagoon or phytopurification…” Tertiary waste water treatment ( water improvement) “… such treatments are suitable for settlement with a population ranging between 2000 and 25000 people., even when combined with actived sludge or adhesive biomass plants because, after the treatment, they refine the final outcome”. Legislative reference: Italian Water Legislative Decree 152/06

5. PHYTOWATERPURIFICATION Fields of application Secondary treatment (biological) for very small and small plants ( from 5 to 100 people ) Treatment Tertiary (water improvement) to reduce impact of medium size plants ( max 20000 people). Rainwater Legislative reference: Italian Water Legislative Decree 152/99

6. PHYTOWATERPURIFICATION The different plants available 1 Systems based on surface flux For tertiary sector and rainwater treatments 2 Systems based on horizontal subsurface flux 3 Systems based on vertical subsurface flux For secondary sector treatments Tertiary water treatment: specific surface needed: 1-2 m2/people Secondary water treatment: specific surface needed: 3-5 m2/people

8. The different kinds of plants Horizontal subsurface flux water basin Secondary wastewater treatment : specific surface needed: 3-5 m2/people

9. Example of a small bi-stadium phytodepuration plant (100 people)

11. The different kinds of plants Surface flux water bed (FWS): macrofite emerging Tertiary treatment (water improvement ): specific surface needed: 1-2 m2/people

12. PHYTOWATERPURIFICATION BASED ON A HORIZONTAL SUBSURFACE FLUX (SFS – H) It is a biologic treatment that employs saturated soil water beds which are contained in tanks or absorbent trays where aquatic plants develop. The alimentation is continuous and the level of the liquid in the tank is regulated by the siphon system contained in the exit pit. This system does not allow removal of nitrogen substances (ammonia). The depuration process is due to: direct action of the plants that are able to maintain oxygenized the substrate, absorbing nutrients (nitrites, phosphates, etc.) They support bacteria and have also a evapo-transpirant function. Bio-demolisher bacteria colonise the roots

13. FITODEPURAZIONE A FLUSSO SUB-SUPERFICIALE ORIZZONTALE SFS - h PHYTODEPURATION BASED ON A HORIZONTAL SUBSURFACE FLUX (SFS – H)

14. PHYTODEPURATION BASED ON A VERTICAL SUBSURFACE FLUX (SFS – V)Wastewaters to be treated flow vertically in the absorbent bed and are directed in tanks with uneven alternate load (through pumps or siphon systems). The wastewaters flow impulsively from the surface passing through a gravel bed (unsaturated zone) and store up at the bottom of the bed (saturated zone) preventing this latter zone from being oxygenized, therefore enabling the denitrification process. Also in this case, the water level in the tank is determined by the siphon system installed in the exit pit.

15. FITODEPURAZIONE A FLUSSO SUB-SUPERFICIALE VERTICALE SFS - v PHYTODEPURATION BASED ON A VERTICAL SUBSURFACE FLUX (SFS – V)

16. Associated Phyto Depurative Mechanisms The removal of pollutants results from biological, physical and chemical processes Biological processes: cooperation between aquatic macrophyte and bacterial colonies dispersed in the surrounding environment Chemical-physical processes: absorbency, precipitation, sedimentation, filtration…

17. Sub-irrigation scheme Sub-irrigation: length of pipes around 10 m people -1 Septic pit Sub-irrigation pipes

18. Subsurface horizontalphytodepuration

19. Absorbent tray used for treating civilian wastewater coming from isolated houses

20. Subsurface phytowaterpurification (200 people) Imhoff + 2 parallel phytos + terminal phyto

21. Tertiary wastewater treatment surface flux

27. Section of a phytowaterpurification basin (example)

30. Phytowaterpurification in closed rooms

31. This is an artificial micro-environment made out of several tanks filled with water, each with a different combination of swamp plants, fishes, snails, fito and zooplankton. The sunlight filters through the greenhouse’s roof. Si tratta di un microambiente artificiale formato da una serie di vasche riempite con acqua, ognuna con una combinazione diversa di piante di palude, pesci, lumache, fito e zooplankton. La luce del sole giunge attraverso il tetto della serra.

36. Municipal wastewater purification by phytotreatment and water recovery Thank you very much for your attention ! Headquarter: Ecologia Applicata S.r.l. Via Porpora, 9 20131 Milano - Italy Phone: (+39) 02 2895978 Fax: (+39) 02 2871159 E-mail: info@ecologia-applicata.itecologia-applicata@iol.it Web site: www.ecologia-applicata.it