Biological nutrient removal
from industrial effluents
by
LEVAPOR BIOFILM TECHNOLOGIES
Complex industrial effluents are mai...
Fig. 1 : Fluidised LEVAPOR carrier
Aerated reactor
Clarifierwith carrier
Fig. 2 Basic flow-sheet of a fluidised bed reacto...
Due to this extremely wide range of possible biokinetic parameters, their
experimental determination using representative ...
Nitrification of industrial effluents by biofilms fixed on LEVAPOR
in the practice
Project 1: Production of organic interm...
Advantages of plant upgrading
Converting bioreactors with suspended biomass, into biofilm technologies by
filling them wit...
Tests in lab and pilot scale biofilm reactors showed, that by proper biological
pre-treatment steps, where toxic inhibitor...
Additional removal of hazardous micropollutants in
LEVAPOR-supported nitrification process:
Due to high adsorbing capacity...
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Nitrification of high ammonia containing Industrial Effluent Using Levapor Carriers

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Application of highly adsorbent, highly porous PU carriers for nitrification of high ammonia containing industrial effluents

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Nitrification of high ammonia containing Industrial Effluent Using Levapor Carriers

  1. 1. Biological nutrient removal from industrial effluents by 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.
  2. 2. Fig. 1 : Fluidised LEVAPOR carrier Aerated reactor Clarifierwith 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.
  3. 3. Due to this extremely wide range of possible biokinetic parameters, their experimental determination using representative effluents is a must ! Elimination ( % ) 100 80 COD 60 40 NH4-N 20 0 NaCl (g/L) 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 microorganisms 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. 220 207 NH4N 195200 [mg/L ] 28 % 180 inlet 160 149 94,9 % outlet 140 120 100 80 60 40 20 10 0 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.
  4. 4. 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. 700 NH4N (mg/L) 600 500 400 NH4N-in Lv (gN/m³xd) 300 200 100 NH4N-out days 0 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
  5. 5. 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.
  6. 6. 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, including nitrification/denitrification. 450,0 N (mg/L) TKNinfl 400,0 350,0 300,0 250,0 200,0 150,0 100,0 50,0 NO 3 N effl NH 4 N effl 0,0 5 5 .05 .05 .05 5 .05 .05 5 5 .05 .05 .05 .050 0 .0 0 0 . . . . 1 1 .11 .11 .11 .11 .11 .11 2 2 .12 .12 .12 .121 1 1 1 . . . . 6 8 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
  7. 7. 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  Petrochemical   Chemistry and pharmaceuticals   Landfill leachates   Steel works   Coal conversion   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. LEVAPOR GmbH Kölner Str. 38 Tel.: + 49- 2173-938715 D- 51379-Leverkusen www.levapor.com Mobile: + 49- 177-786 5533 Germany E-mail: levapor@web.de

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