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Ammonia Stripper NAS

• Nijhuis and H2OK formed joint venture to provide the UK market with a true single source supply.

• Collaboration between two companies working together as one with shared vision of quality, customer service, reliability, value, on going support.

• H2OK Water and Energy: Wastewater treatment, waste to energy with a design, build and operate capability.

• Nijhuis Water Technology: Global provider in the design manufacture and construction of innovative value from waste, wastewater and recycling solutions, active in 50 countries

• Global presence with over 2400 reference sites

• National presence with over 160 sites in the UK

• Nijhuis and H2OK formed joint venture to provide the UK market with a true single source supply.

• Collaboration between two companies working together as one with shared vision of quality, customer service, reliability, value, on going support.

• H2OK Water and Energy: Wastewater treatment, waste to energy with a design, build and operate capability.

• Nijhuis Water Technology: Global provider in the design manufacture and construction of innovative value from waste, wastewater and recycling solutions, active in 50 countries

• Global presence with over 2400 reference sites

• National presence with over 160 sites in the UK

Global network & 2400 references

Water Treatment l Recycling l Waste to Valuable

Phosphorus

Nitrogen

Oil

Fats

Starch Waste water Proteins Waste

Manure

Realizing the value of waste & water

Heat

Energy Biofuels

Animal feed

Ingredients Process water Fertilizers

Algea

Green gas

Ammonia stripping

• High ammonia levels are toxic to both aerobic and anaerobic

biological processes.

• The Nijhuis Ammonia Stripper or NAS is a process to convert

Ammonia into Ammonium sulphate ((NH4)2SO4) solution.

• This solution is an effective nutrient with market value.

• The NAS is designed to recover this nutrient from liquids like

digestate or slurries.

Nitrogen removal from digester feed, digestate or manure

Ammonium sulphate can be sold as a fertilizer

Process steps

• Stripping of liquid with gas @ 60-

80 °C

• Gas scrubbing with sulphuric acid

• Ammonium sulphate is formed in

scrubber column

NAS – Ammonia stripping and ammonium sulfate

production

Stripper

• The substrate in the stripping tank is adjusted to optimal

conditions

• 60 to 80 degrees °C

• pH 8 – 9, in order to strip the ammonia from the

substrate

• Residence time is typically 10 – 20 h.

• Gas is circulated through the substrate in the stripping tank

and will transport ammonia from the stripper tank to the

scrubber column.

• Heating takes place into two steps:

• Heat exchanging from effluent to influent in order to

recover energy.

• Final heating with steam or other available heat

source.

Scrubber

• The gas containing Ammonia is washed

in scrubber column with sulphuric acid.

Ammonia and Sulphuric acid are

converted into an Ammonium sulphate

((NH4)2SO4) solution.

• Removal efficiency is 98 – 98 %.

• Carrier gas free from Ammonia is reused

in the Stripping tank.

• Alternative to Sulphuric acid Nitric acid or

Phosphoric acid can be used in order to

produce other nutrients.

NAS – Ammonia stripping and ammonium sulfate

production

Applications (Installed before anaerobic processes)

• Reduce Nitrogen levels and toxicity in the anaerobic

treatment

• Hydrolysing of COD

NAS – Ammonia stripping and ammonium sulfate production

Applications (Installed after anaerobic processes)

• Create maximum output

• Prevent toxicity in the aerobic stage following the NAS

Ammonia stripper Laboratory trials

Laboratory scale tests have been

performed together with the Agricultural

University of Wageningen, WUR.

Batch testing was executed in order to

study removal kinetics.

Removal Kinetics

• Removal of NH3 from digestate at pH 8,5 at 80 C

• Gas is bubbling through the liquid

0

20

40

60

80

0 5 10 15 20 25

Re

mo

val e

ffic

ien

cy [

%]

Time [h]

Digestate

tN removal [%]

NH3 reduction [%]

Poly. (NH3 reduction [%])

• Pilot trials have undertaken automatically

with digestate feedstock

• The pilot was used to prove the

experimental lab scale experiments in a

continuous process.

Ammonia stripper Pilot trials

NAS - Ammonia stripping and ammonium sulphate production

General Arrangement Contact and de-foaming

column

Gas scrubber

• Currently under construction

building the NAS Fertilizer

Production Plant FPP for

treatment of digestate prior to

aerobic treatment at Bernard

Matthews Holton site.

• Treatment is required in order to

prevent Nitrogen problems in the

excising wastewater treatment

plant.

Application of the Nijhuis Ammonia Stripper

• The plant is built as a containerized unit

with a separate concrete stripper tank.

• Stripper tank, scrubber column are

located outside.

• All other equipment is located inside.

Fertilizer Production Plant at Bernard

Matthews’ Holton Site

Questions?

www.nijhuis-water.com

www.h2ok.co.uk