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DEMONSustainable Nitrogen Removal with Deammonification

HenkWim de Mooij

DEMON: stable and sustainable N-removal

Developed at Innsbruck University, Austria

Full scale experience since 2003 at Strass WWTP

Nine full scale installations in operation in Europe, six under construction (mostly references on liquors from municipal sewage sludge)

Technology under license from University of Innsbruck (Dr. Bernhard Wett)

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Side stream treatment implemented

effluentinfluent

Digester

Primary sedimentati

on

Activated sludge

Final clarifier

Dewatering

Sludge

Liquor Treatment

Return Liquors

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Nitrogen CycleReduced Organic

N-components

N-Assimilation(plants, micro-

organisms

NO3-

NO2-

N2 NH3

N-fixation

N2O

Nitrification(Nitrobacter)

Nitritation(Nitrosomonas)

N-Assimilation(plants, micro-

organisms

Microbial degradation

NO2-

SHARON

DEMON

Denitrification

0.5 mol N2

1 mol NO3-

1 mol NO2-

C-source → sludge

1 mol NH4+

1 mol NO2-

CO2 → sludge

O2

O2

CO2 → sludge

C-source → sludge

Traditional biological nitrogen removal

DEMON nitrogen removal: deammonification

0.5 mol N2 + 0.1 mol NO3

1 mol NO3-

1 mol NO2-

C-source → sludge

1 mol NH4+

0,5 mol NO2-

0,5 O2

O2

C-source → sludgeCO2 → sludge

CO2 → sludge

CO2 → sludge

1.25 NH4+ + 1.25 O2 1.25 NO2

-

NH4+ + 1.25 NO2

- N2 + 0.25 NO3- + 2 H2O

2.25 NH4+

Aerated period

Anoxic period

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How does it work?

DEMON characteristics

Standard SBR configuration Low energy requirement, as only 55% of ammonia is oxidised

to nitrite; No requirement for an external source of carbon (such as

methanol); Low sludge production; Stable process due to pH control, process adjusts to changes

in flow and load automatically; No sensitivity to phosphate in sludge liquors, no pre-treatment

required.

DEMON Control

Control aeration Sufficient oxygen for nitrification Oxygen level limiting for Nitrite oxidizing bact.

Control nitrification process Produce nitrite for deammonification process Avoid inhibition due to excess nitrite

Control sludge age Sufficiently long for

anammox to grow (>20 days) Too short for NOB to grow

0.3 mg/l O2

pH control

Cyclone

pH Control of nitrification

- Oxygen

- pH

Using pH for nitrite control

- Oxygen

- Nitrite

Cyclone for sludge age control

Surplus sludge

Surplus sludge discharge (NOB)

Sludge returnto reactor(anammox bacteria)

DEMON references (operational)

Location Year Capacity Liquor source

Heidelberg, D 2008 480 m³/d, 600 kg/day NH4-N Mesophilic digested sludge

Thun, CH 2008 300 m³/d, 400 kg/day NH4-N Mesophilic digested sludge

Glanerland, CH 2007 250 m³/d, 250 kg/day NH4-N Mesophilic digested sludge

Strass, A 2004 250 m³/d, 500 kg/day NH4-N Mesophilic digested sludge

Plettenberg, D 2007 100 m³/d, 80 kg/day NH4-N Mesophilic digested sludge

Limmattal, CH 2010 250 m³/d, 250 kg/day NH4-N Mesophilic digested sludge

Etappi Oy, Fi 2009 330 m³/d, 990 kg/day NH4-N Biogas production

Balingen, D 2009 400 m³/d, 192 kg/day NH4-N Mesophilic digested sludge

Zalaegerszeg, Hu 2010 160 m³/d, 160 kg/day NH4-N Mesophilic digested sludge

Gengenbach, D 2008 50 m³/d, 50 kg/day NH4-N Mesophilic digested sludge

Apeldoorn, NL 2009 1270 m³/d, 1690 kg/day NH4-N Mesophilic digested sludge

DEMON references (under construction)

Location Year Capacity Liquor source

Kecskemet, Tu 1300 kg/day NH4-N Mesophilic digested sludge

Kokkola, Fi 600 kg/day NH4-N Mesophilic digested sludge

Lahr, D 235 kg/day NH4-N Mesophilic digested sludge

Erpfendorf, D 120 kg/day NH4-N Mesophilic digested sludge

Alltech, D 2400 kg/day NH4-N Biogas/yeast

Rickenbach, D 50 kg/day NH4-N Dairy

Nieuwegein, NL 450 kg/day NH4-N Mesophilic digested sludge

Amersfoort, NL 600 kg/day NH4-N Mesophilic digested sludge

Apeldoorn Sludge Treatment

CHP

Digesters

DEMON LTP

DEMON Nieuwegein

Design Basis DEMON Nieuwegein

Parameter Unit Average Max Peak

Flow m3/d 258 420 480

NH4-N mg/l 1.059 1.012 1.012

  kg/d 273 425 486

Batch proces DEMON

No. of cycles per day : 4

Cycle volume : 120 m³/cycle (peak)

Cycle time : 6 h

1. Fill + Aerate phase : 4,5 h

1. Settlement phase : 0,75 h

1. Discharge phase : 0,75 h

DEMON reactorProcess Flow Diagram

Filtrate Buffer Tank

DEMON Reactor

Cyclone

Filtrate Break Tank

Surplussludge

DEMON effluent

G.A. Drawing

DEMON reactor Nieuwegein WWtP

Buffer tank in reactor

Aerated / Anoxic zone in reactor

DEMON Cyclone

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Thank you for your attention

ANY QUESTIONS?

HenkWim.demooij@grontmij.nlBert.Geraats@grontmij.nl