High Performance, flexible, durable Levapor Carriers made of PU foam impregnated with activated carbon for wastewater treatment

1. Dr. Imre Pascik
LEVAPOR GmbH
www. levapor.com
Germany
Leverkusen,
LEVAPOR – porous, adsorbing carrier
for bioprocess improvement

2. Wastewater treat.plant
„Bayer Tower Biology“
Start: 1980
Reactors: 4x16.000 m³
LEVAPOR biocarrier and several other wastewater treatment
technologies Dr.Pascik has developed and applied in the Environmental
Biotechnology Center of BAYER AG in Leverkusen, Germany.

3. somonas europaea
Biodegradation of pollutants
occurs via teamwork of
microorganisms united
in sludge flocs
Important result of research work :
Some important, non-flocculating
organisms will be washed out from
bioreactor, resulting reduced plant
efficiency
Solution: Biofilm technology
via immobilisation, cell growth
on
solid surfaces, “carriers“ made of
plastics, sand, glass, etc.

4. Our REQUESTS on OPTIMAL CARRIER
PROPERTY
1. Adsorbing capacity
EFFECT
- binding toxic pollutants
- fast colonisation+biofilm
- fast startup at high level
2. Porosity, high inner surface - protection of the biofilm
(high biomass content)
- high space-time-yields
3. Fast wetting
- homogene fluidisation
4. Water binding
- mass transport, bioactivity
5. Proper fluidisation
- lower energy consumption

5. LEVAPOR, adsorbing, porous biocarrier have been
designed on basis of above mentioned requirements

6. Specialty: high content of powdered activated
carbon
resulting other effects than simple cell adhesion :
Adsorption of inhibitors lower toxicity in

7. Fast colonisation  fast biofilm generation 
fast and stable bioprocess

8. Confirmation test – 1 (next diagram) :
Biodegradation of toxic 2-Chloroaniline (2-CA)
in two parallel discontinuously operated aerobic lab plants
shows excellent the mechanisms of processes:
1. In the first 2 hours 2-CA became ca. 65% adsorbed, on
LEVAPOR , while toxicity in the medium dropped .
2. Biodegradation of 2-CA in LEVAPOR-reactor started
and became completed after 240 hours.
3. Quantity of released Cl– ions confirmed a quantitative
degradation.
4. 2-CA in the reactor without LEVAPOR has not been
degraded.

9. Biodegradation of 2-CA with immobilised vs. suspended bacteria
( Univ. of

10. Confirmation test -2
Degradation of 2-Chlorobenzoic acid under anaerobic
conditions
in parallel discontinuously operated anaerobic lab plants
confirmed the same mechanisms .
1. In the LEVAPOR-plant 2-CBA became adsorbed, biofilm
generation and degradation started fast (CH4-production)
2. Biodegradation of 2-CA in LEVAPOR-reactor started and
became completed after 240 hours.
3. Quantity of released Cl– ions confirmed a quantitative
degradation.
4. 2-CA in the reactor without LEVAPOR has not been degraded.

11. Anaerobic test for carrier screening
(Prof. H.SAHM, DUS.)

12. Application:
„cubes“
12 to 15 vol.% of 20*20*7 mm

13. Primary settler
Aerated basin + carrier
Clarifyer
LEVAPOR in a fluidised bed biofilm reactor:
„ MBBR“

14. The first application in the practice was in a pulp mill with
toxic effluents from pulp bleaching:
Q = 10.000 m³/d COD = 3.500-4.000 mg/L AOX~ 90 mg/L
Lab tests :
Aerobic degradation achieved 35 to 40% COD-removal.
Anaerobic tests with LEVAPOR = 65 - 75 % COD-removal
+ Aerobic post treatment removed 50 % of residual COD.
ANA/AER-pilot tests:using LEVAPOR,size of ANA-reactors
was reduced by 75 %! 15.000 m³ instead of 65.000 m³ !
Startup: 1990, only 2 of 3 ANA-reactors were with LEVAPOR

15. LEVAPOR
gran.activ. carbon
unmodified PURfoam
suspended
anaerobic sludge
Effect of carrier types on COD-elimination under anaerobic

16. EQUALISATIO
N
AEROBIC
REACTOR
S
ANAEROB
.
REACTOR
S
Plant for anaerobic-aerobic treatment of toxic pulp mill effluents by
LEVAPOR-supported microorganisms

17. Startup: 1990, only 2 of 3 ANA-reactors were started with LEVAPOR
in order to compare the effect of immobilisation.
After few weeks a toxic shock has stopped the reactor without LEVAPOR
Nowadays: ~ 85 % COD- removal , 4 – 6 t/d sludge, 14.000 m³/d biogas

18. 3,5
kgCOD/m³ x day
immob. biomass
3
2,5
2
1,5
susp.biomass
1
0,5
0
May 90
1
3
5
June 90
7
9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41
Comparison of biofilm reactors versus suspended

19. LEVAPOR- case history No. 2
Upgrading of an existing municipal
plant for
nitrification in Espoo + Helsinki
Problem:
Nitrification in existing plants, designed for
BOD-removal is not efficient in winter months.
Standard proposal: doubling of reactor
volume.
Our idea: upgrading of the existing plant by fixing
nitrifying biomass on LEVAPOR carrier !
Field-test: 12 vol.% LEVAPOR carrier cubes were

20. 50,0
N (mg/L)
TKNZul
45,0
40,0
35,0
30,0
25,0
20,0
NO3NAbl
15,0
10,0
5,0
NH4NAbl
07.11
02.02
02.05
0,0
1
3
5
7
9
11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49
N-concentrations after addition of LEVAPOR at 10 to17°C
After 3-4 weeks a stable nitrification has been establihed !

21. 60,0
N (mg/L)
50,0
TKNZul.
40,0
30,0
20,0
NH4NAbl.
NO3NAbl.
10,0
days
0,0
1
3
5
7
9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47
Pre-denitrification resulted in lower outlet-NO3N concentrations

22. A usual aeration intensity achieves a nearby quantitative fluidisation

23. Addition of 12 vol.% LEVAPOR carrier into
aerated basin of existing municipal plant in
resulted in
efficient nitrification within 3 weeks, remaining
stable over years !
Benefits for customers :
•
75,- 105 €/m³ costs instead of ~ 250- 350,- €/m³ for new
reactor volume (savings: 175 - 275,- €/m³ !).
•
ca. 15- 25 % less excess sludge.

24. Dimension
NINGAN WWTP
m³/day
Values (Aug. 2011)
22.000
Volume of reactors
m³
3200 (4 x 800)
Volume LEVAPOR
m³
500 (15,6 %)
Hydraulic ret. time
h
3,5
kg/m³xday
2,2
Legend
Water flow
Lv, COD
Results 2011
in
out
% removal
COD
mg/L
320
20-25
92 – 94
BOD5
mg/L
158
5
97
NH4N
mg/L
24
2-3
88 - 92