Nitrification of high ammonia containing Industrial Effluent Using Levapor Carriers
Biological nutrient removal
from industrial effluents
LEVAPOR BIOFILM TECHNOLOGIES
Complex industrial effluents are mainly polluted by molecules with different
• chemical structure, biodegradability, toxicity and contain often up to
• 15 to 50 g/L salts, characterized further by temporary fluctuations.
Due to their higher pollution with organic and inorganic N-compounds, fish-
toxicity of free ammonia, NH3 and carcinogenicity of nitrite (NO2
) ion ,
biological nutrient removal via nitrification and de nitrification becomes
very important also for industrial effluents.
Due to the
slow growth rate and low cell yield of nitrifying microorganisms
(resulting their wash-out of the bioreactor), respectively
their remarkable sensitivity to changes of pH, temperature and salinity
organic and inorganic inhibitors, the key reaction of nutrient removal
process, NITRIFICATION becomes often unstable.
Because of their high adsorbing capacity and porosity, especially
LEVAPOR carrier do support nitrification, by :
Fast microbial colonisation and generation of active bio films result in
- higher resistance against inhibiting effects and
- higher process performance, while their
High adsorbing capacity reduces inhibiting effects and enables a
fast biodegradation of inhibitors.
LEVAPOR supported biofilm reactors
Most practicable are fluidised bed reactors, containing 12 to 15 vol. % LEVAPOR .
Due to the low density of the cubes, even oxidation devices of existing plants are
sufficient for the fluidisation of the filter bed, enabling easier upgrading of existing
plants. Retention of carrier with 20x20x7 mm within preferably bottom-aerated
reactors occurs via adequate screens and/or grids.
Fig. 1 : Fluidised LEVAPOR carrier
Fig. 2 Basic flow-sheet of a fluidised bed reactor
Nitrification of industrial effluents
Depending on waste water matrix, i.e. structure and concentration of organic
and inorganic pollutants, nitrifying microorganisms are able to oxidize
ammonical nitrogen in the practice from
20 to 25 g N / kg biomass(MLSS) per day (inhibiting conditions) up to
160 to 220 g N / kg biomass (MLSS) per day (non inhibited process) .
Increasing salinity results in decreased uptake of organic pollutants and
especially nitrogen, meaning lower degrees of COD- and N-elimination(Fig.3).
Presence of even low concentrations of special inhibitors results often in a
crash of nitrification process even under continued non inhibited COD-removal.
Due to this extremely wide range of possible biokinetic parameters, their
experimental determination using representative effluents is a must !
Elimination ( % )
33 35,3 39,6 42,9 46,1 49,4 52,7 56
Fig. 3 Effect of increased salinity on non-inhibited nitrification by suspended
By immobilizing nitrifying biomass, negative effects of inhibitors can be
reduced remarkably (Fig. 4, right: 94,5 % nitrification, versus only 28% achieved
by suspended biomass, left). Both, higher resistance and higher number of
microbial cells fixed on carrier do contribute to stability of the process.
[mg/L ] 28 %
suspended biomass immobilised biomass
Fig.4 : Effect of biomass immobilisation on nitrification of saline and inhibiting
chemical effluents (salinity:20-25 g/L,COD~1600mg/L) at Lv~ 0,25gN/Lxd.
Nitrification of industrial effluents by biofilms fixed on LEVAPOR
in the practice
Project 1: Production of organic intermediates, complex, concentrated effluents:
COD ~ 3100 mg/L,
TKN ~ 820 mg/L
Salinity ~ 20 to 34 g/L .
Existing effluent treatment plant (WWTP), designed for COD-removal.
Key question: is a plant upgrading sufficient for a required nitrification and
denitrification ? is it cheaper than plant extension ?
Calculations showed, that provided a stable nitrification at volumetric loading
rates of Lv > 0,6 kgN/m³x day, upgrading would be feasible.
Results of continuous tests in a pilot scale fluidised bed reactor showed that
a) Process using suspended biomass achieved stable nitrification until
Food:Mass-ratio ~ 70 g N / kg biomass x day, corresponding with
loading rates of Lv ~ 0,3 – 0,35 kgN/m³ x day , which is not enough.
b) The same biomass, fixed on LEVAPOR carrier achieved a full nitrification of
these effluents at required loading rate(Fig. 5) .
c) Estimated cost savings of plant upgrading: ca. 50% of plant extension costs.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Fig. 5 : Nitrification pilot test confirming feasibility of the process at
Lv ~ 0,6 kgN/m³xday
Advantages of plant upgrading
Converting bioreactors with suspended biomass, into biofilm technologies by
filling them with 12 to 15% of adsorbing LEVAPOR carrier, biomass performance
and process stability can be improved, meaning
Faster - upgrading can be realised within days
better - because of higher performance and stability of biofilms, and also
more economical – because of lower costs of plant upgrading, meaning
80 to 110 Euro/ m³ for plant upgrading versus
280 to 400 Euro/m³ for a plant extension, further
regarding to savings, via lower sludge production of biofilm systems.
Fig.6 1000 m³ aerated basin converted into a fluidised bed
reactor for LEVAPOR supported nitrification.
Project 2 : Production of toxic agrochemicals (new plant)
COD : 8000 to 11000 mg/L
TKN : 600 to 750 mg/L
Salinity: 10 to 22 g/L
Active agents: up to 150 mg/L, inhibiting both, COD-removal and nitrification.
Tests in lab and pilot scale biofilm reactors showed, that by proper biological
pre-treatment steps, where toxic inhibitors would be converted into non inhi-
biting metabolites, also nitrification of generated ammonia becomes feasible.
Fig. 7 Multi-step plant for biotreatment of toxic agrochemical effluents,
N (mg/L) TKNinfl
.05 .05 .05
.05 .05 .05 .050 0
.0 0 0
. . . .
.11 .11 .11 .11 .11 .11
.12 .12 .12 .121 1 1 1
. . . .
13 15 20 22 27 29
4 6 1 3
18 201 1
Fig. 8 Nitrification of toxic agrochemical effluents in a pilot scale biofilm
plant using LEVAPOR carrier
Additional removal of hazardous micropollutants in
LEVAPOR-supported nitrification process:
Due to high adsorbing capacity of LEVAPOR, hazardous micropollutants
become fixed and more bioavailable for biofilms, resulting in their higher
degree of biodegradation, than by suspended microorganisms:
PAH (EPA-method) = + 85 % higher removal
Bisphenol-A = + 85 to 92 %
Aniline = + 90 to 93 %
Nitrobenzene = + 85 to 98
Our experiences with nitrification of complex industrial effluents
Chemistry and pharmaceuticals
Textile and leather industry
Sludge processing effluents
Our services for you
we do offer also our services in designing tailor made problem solutions,
based on 40 years experiences on biofilm technologies and nutrient removal,
both in the field of science and in the practice. Our tools are:
Analysis of the problem
Elaboration of alternatives for problem solution , supported by
Practice oriented biotests (especially for nitrification),
Process Design and/or Engineering
Production and delivery of the required LEVAPOR type and
Plant startup using optimized mixed biomass, enriched with microbes
essential for degradation.
Presented information are based on experiences with application LEVAPOR carrier. Testimonies on expected
effects can be made in individual case only on basis of investigations of given emissions and in some cases on
basis of practice relevant experiments.
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