1. Environmental Technology ChimH409 (2-0-1)
Bruface
Universite Libre de Bruxelles
Dept Water Pollution Control
Environmental Technology ChimH409 (2-0-1)
Michel Verbanck
2012

2. Course structure Part 1. Introduction (incl. generic methods)
Part 1. Introduction (incl. generic methods)
Part 2. Air pollution control engineering
Part 3. Water & wastewater treatment
Part 4. Solid and hazardous wastes

3. Part 3.
Water & wastewater treatment

6. Membrane separation techniques and their domain of application

7. pressurized membrane filtration: operation with prevention of fouling

9. Hollow fibers

10. ultrafiltration unit, Vigneux 55000 m3/day

11. UV dose mJ/cm2 4log inactivation (99.99)
Pathogens
UV dose mJ/cm2 4log inactivation (99.99)
Cryptosporidium parvum oocysts
<10
Giardia lamblia cysts
Vibrio cholerae
2.9
Salmonella typhi
8.2
Shigella sonnei
Hepatitis A virus 30
Poliovirus Type 1
Rotavirus SA11 36
water disinfection by UV irradiation

12. European Water Framework Directive 2000/60
requires that all inland and coastal waters within defined river basin districts must reach at least good (ecological) status by 2015
transboundary if necessary
defines how this should be achieved through the establishment of environmental objectives and ecological targets for surface waters
action plan to be published end 2009 by all Member States

13. s

15. Phosphate removal BNR plants Discard phosphate anaerobically
Luxury aerobic uptake of P in aerobic stage
Process adaptations for N and P removal
EBPR plants
Air
Wastewater
Anaerobic
Anoxic
Aerobic

16. Enhanced biological phosphate removal (EBPR)
(Melasniemi 2000)
Enhanced biological phosphate removal (EBPR)
the principle
Dry solids of conventional activated sludge have a total phosphorus contents of %, while those of enhanced biological P removal plants (based on a luxury-uptake process) can achieve up to > 4 % TP.
Under anaerobic conditions phosphate-accumulating organisms (PAOs) are not able to grow but can accumulate and store organic substrate by converting small organic acids into poly-hydroxy-butyrate (PHB) and similar energy rich organic compounds. For this process the PAO bacteria need energy which they gain under anaerobic conditions from the conversion of stored energy-rich polyphosphate (polyP) to dissolved phosphate which is released to the water under these conditions.
When oxic conditions are met again, PAOs reconstitute their internal polyphosphate ‘batteries’ resources. This process is called luxury uptake (because the P uptake is then far higher than what would occur in usual biotreatment conditions).

17. Degassing
Pressurized air
Anaerobic
This process will be illustrated by the technical visit of the biological wastewater treatment plant in Waterloo (compulsory visit for all, including EIB students). s

19. struvite precipitation
more sustainable, because it involves nutrient recovery

20. s

21. 1 - Agitator
2 - Flocculator
3 - Settler
4 - Raw water in
5 - Settled water out
6 - Purge

22. Nitrogen removal Nitrification (Nitrosomonas and Nitrobacter)
NH3 + O2  NO2-  NO3-
Denitrification
NO organics  CO2 + N2
Process adaptations
Air
Anoxic
Aerobic

23. s

24. s

25. electron acceptor

26. s

27. s

28. s

29. Electron acceptors s

30. Biostyr process (OTV) polystyren foam low-density microbeads
3 to 4 mm diameter s
Biostyr process (OTV)

31. s

33. Anammox process NH4+ + NO2-  N2 + 2H2O
In the 1990s, researchers discovered that there could be other biological
processes other than nitrification/denitrification that are able to remove nitrogen from
wastewater. The phenomenon of anaerobic ammonia oxidation was observed and the
scientists at TU Delft identified the organisms responsible for the process to be from the
Planctomycetes family. With this information, TUD Prof Van Loosdrecht designed an innovative process – Anammox (ANaerobic AMMonium OXidation) process
which converts ammonium to harmless nitrogen gas
This process only requires the conversion of half of the ammonium to nitrite resulting in the reduced need for aeration, thus saving energy.
The bacteria involved in the Anammox process will then convert ammonium and nitrite together into nitrogen gas without the need for any additional organic carbon compounds. Anammox is able to reduce carbon dioxide emissions by up to 90% compared to conventional nitrification / denitrification processes. It occupies up to 50% less space and reduces aeration energy by up to 60%.
NH4+ + NO2-  N2 + 2H2O

35. If residence time is excessive (> 2hr) the risk in secondary clarifier is that denitrification takes place, generating N2 microbubbles which can float sludge flocs. What we obviously want to avoid is sludge loss into the receiving water body we actually wanted to protect in the first place.
On site, however, this problem should be differentiated from the bulking one (due to proliferation of filamentous bacteria).