Presentation outline I. General introduction manure excesses & manure treatment

1. Manure processing to reusable water using constructed wetlandsMeers E., Michels E., March 8, 2011

2. Presentation outline I. General introduction manure excesses & manure treatment II. Treatment to dischargeable water using constructed wetlands as a tertiairy step II. Project overview re-use of treated effluents as secondary water resource

3. I. General Introduction

4. The Flanders situation Intensive industrial farming results in localized nutrient (N,P) excesses at a regional level. Similar situations in US (NC), France (Bretagne), Netherlands, Germany (Nord Westfalen), Italy, Manure excess on soil balance Exceedance over EU Nitrate directive % in 2003-2004 % in 2004-2005 % in 2005-2006

5. Manure processing Animal manure Solid fraction Soil enhancer Physical separation Composting Liquid fraction Fertilizer Spreading over land Nutrient reduction by biological treatment

6. Manure processing Animal manure Solid fraction Soil enhancer Physical separation Composting Liquid fraction Fertilizer Spreading over land Dischargeable water Nutrient reduction by biological treatment Constructed wetlands

7. Cascade of plant- & microbial based processes Constructed wetlands

8. Rich diversity of plant species and substrates Constructed wetlands

9. Constructed wetlands “Intelligent design”: control in function of crucial monitoring parameters, feed forward & feedback loops

10. Cost per m3 Constructed wetlands were designed as an alternative for spreading manure Surface: In general: 1 m² / 1 m³ manure per year (~ 1 ha for 10.000 pigs) In practice: > 1 m² / 1 m³ manure Cost (current systems): 3,5-4,5 €/m³ (incl. operational and investment cost, period 10 year) After depreciation (10 years): 2,5-3,0 €/m³ Various additional break-throughs pending with impact on : capacity (m3/m2.j) and hence cost per m3

11. II. Treatment to dischargeable water

13. Constructed wetlands Liquid fraction after biology Effluent Constructed Wetlands < 15 mg/l total nitrogen < 2 mg/l totaal phosphor < 125 mg/l COD 300 mg/l total nitrogen 250 mg/l total phosphor 3000 mg/l COD

14. Constructed wetlands VLAREM standard environmental quality standard N content

15. III. Project overview: water re-use

16. Water scarcity & water re-use Animal manure • sufficient water supply is one of the most important environmental and economical challenges in agriculture in the near future • use of purified water on the farm is scarce • is reuse of end effluent of constructed wetlands an option? Physical separation Liquid fraction Dischargeable water Nutrient reduction by biological treatment Constructed wetlands

17. Project 5 different CW locations, monthly sampling physico-chemical parameters (non-limitative list) SS EC pH Ptot ortho-P NTU hardness Ntot NO2 NO3 NH4 BOD COD Ca Mg K Na F Cl SO4 Al Cd Cu Fe Mn Ni Pb Zn Co Cr bacteriological parameters C. perfringens Enterococci total Coliforms SalmonellaE. coli colony count (37°C) colony count (22°C) spores sulfite red. Clostridia reuse options (high & low grade) drinking water live stock cleaning water irrigation cooling water

19. ICH – 0,5 ha Wetland area GI – 3 ha Prim. & Sec. Manure treatment Pig farm PI – 1 ha WVL– 3 ha LA – 0,5 ha

20. Results- compared to pig drinking water • Overall excellent results • Problem parameters • Location Ex. Other spore elements: mainly below DL

21. Total nitrogen • VLAREM (15 mg/l) • No criteria for drinking or irrigation water Ntot mg/l Location

22. Nitrate • Drinking water (taste) pig: 100 mg/l • ≠appl. Irrigation, process-, cooling- & cleaning water : -  algal bloom, leaching NO3 mg/l Ntot mg/l Location

23. Total phosphorus • VLAREM (2 mg/l) • No criterium for drinking water essential element, non toxic, eutrofication pipes • Intensive agri- & horticulture: 15 mg/l • algal bloom storage • Process-, cooling- & cleaning water: - •  eutrofication P (mg/l) Location

24. Total colony count (37°C) Criterium drinking water pig: 100.000 cfu/ml Cfu/ml Time

25. Hardness • Drinking water pig: 20 D°H • ≠appl. irrigation 21,5 D°H • Risk clogging • Cool- & cleaning water  salt deposit upon heating, ex. cooling greenhouse Hardness (D°H) Location

26. Iron content • Variability in location • Drinking water pig: 0,5 mg/l  taste, smell, clogging • Irrigation: 0,5-15 mg/l +: grassland, vegetables, green house farming, cultivation trees -: open-air culture, intensive agri- & horticulture, substrate culture • Rust deposit • Ground water in Western Flanders: up to 4 mg/l • Iron removal necessary -: Fe (mg/l) Location

27. Spores sulfite reducing Clostridia Criterium drinking water pig: 0 cfu/ 100 ml Cfu / 100 ml Time

28. Conclusions • preliminary results indicate that effluent quality scores better than initially anticipated, both for the bacteriological as well as the physicochemical parameters. • even for high grade applications constraints for reuse were limited to parameters which are easy to address using simple polishing steps. • we expect that reuse of constructed wetland effluent in various applications will have important economical and environmental benefits.

29. On site polishing

30. Future perspectives Biomass for energy Algaeproduction Aquaculture Biodiversity

31. Contact • Prof. dr. ir. Erik Meers • (e-mail): erik.meers@UGent.be • dr. ir. Evi Michels • (e-mail): evi.michels@UGent.be • even for high grade applications constraints for reuse were limited to parameters which are easy to address using simple polishing steps. • we expect that reuse of constructed wetland effluent in various applications will have important economical and environmental benefits.