LEVAPOR – porous, adsorbing carrier for bioprocess improvement

Dr. Imre Pascik LEVAPOR GmbHwww. levapor.com Leverkusen, Germany

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.

Nitrosomonas europaea

Important result of research work :Some important, non-flocculating organisms will be washed out from bioreactor, resulting reduced plant efficiencySolution: Biofilm technologyvia immobilisation, cell growth onsolid surfaces, “carriers“ made ofplastics, sand, glass, etc.

Target: Synthesis of biocarrier

Biodegradation of pollutants occurs via teamwork of microorganisms unitedin sludge flocs

Our REQUESTS on OPTIMAL CARRIER

PROPERTY EFFECT 1. Adsorbing capacity - 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

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

Specialty: high content of powdered activated carbon resulting other effects than simple cell adhesion : Adsorption of inhibitorslower toxicity in bioreactor fast bioprocess start stable process

Fast colonisation fast biofilm generation fast and stable bioprocess

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.

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

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.

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

Application: 12 to 15 vol.% of 20*20*7 mm „cubes“ in a fluidised bed reactor

LEVAPOR in a fluidised bed biofilm reactor: „ MBBR“ a) screen for carrier retention b) adequate aeration

Primary settler Aerated basin + carrier Clarifyer

The first application in the practice was in a pulp mill withtoxic 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

Effect of carrier types on COD-elimination under anaerobic biotreatment of toxic pulp mill effluents in lab scale plants

LEVAPOR

gran.activ. carbon

unmodified PUR-foam

suspended anaerobic sludge

Plant for anaerobic-aerobic treatment of toxic pulp mill effluents by LEVAPOR-supported microorganisms

EQUALISATION

ANAEROB. REACTORS

AEROBICREACTORS

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

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Comparison of biofilm reactors versus suspended biomass

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 added into the aerated basin !

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N-concentrations after addition of LEVAPOR at 10 to17°C After 3-4 weeks a stable nitrification has been establihed !

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Pre-denitrification resulted in lower outlet-NO3N concentrations

A usual aeration intensity achieves a nearby quantitative fluidisation

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.

Legend Dimension NINGAN WWTP

Values (Aug. 2011)Water flow m³/day 22.000

Volume of reactors m³ 3200 (4 x 800)

Volume LEVAPOR m³ 500 (15,6 %)

Hydraulic ret. time h 3,5

Lv, COD kg/m³xday 2,2

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