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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