The document discusses several technologies being tested and demonstrated at the Altenrhein wastewater treatment plant in Switzerland as part of the nextGen project. These include: 1. Production of renewable granular activated carbon from sewage sludge and cherry pits through pyrolysis and activation, which is being tested at a pilot scale. 2. Large scale demonstration of ammonium recovery using a hollow fiber membrane contactor to optimize the process and determine performance metrics for nitrogen recovery. 3. Phosphorus recovery through thermochemical treatment of sewage sludge to produce a PK fertilizer, with preparatory trials completed and pilot tests planned for late 2020.

1. 1
WA
TER
ENERGY
MA
TERIALS
nextGen Demo Case
SwitzerlandAltenrhein
Anders Nättorp,
School of Life Sciences, FHNW
The consortium has receivedfunding from the
European Union’s Horizon 2020 research and
innovation program under grant agreement No.
776541.
FOLLOW US

2. Altenrhein, Switzerland
Facts
• Wastewater 100,000 PE
• Sludge treatment 300,000 PE including
co-digestion of food waste
• Full scale elimination of micropollutants
• Full scale ammonia stripping
Vision: Improving the use of resources by
closing cycles in wastewater treatment and
sewage sludge treatment
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3. Altenrhein in the frame of nextGen
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4. Baseline and nextGentechnologies
Water
Energy
Material
Baseline
NG new
NG remove
GAC-BAC
Adsorption
(from 2019)
Digester
Ammonia
stripping
Dewatering Drying
Pyrolysis (pilot)
1. Activated Carbon
2. Fertilizer
Heat
pump
(NH4)2SO4
PK-fertilizer
Todistrict heating
Sludge to cement works
Excess
sludge
WWTP
Activated Carbon
Granulation
(pilot)
NPK(S)-fertilizer
Local
biomass
Ozonation
Potassium
source
e.g.
C6H7KO2
Co-Substrate Sludgefrom
3rd party
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Digested
sludgefrom
3rd party
Dewatered
sludgefrom
3rd party

5. 5
Renewable granular activated carbon(GAC)
GOAL:ProductionofGAC viapyrolysis & activation
All methods have been tested with two
renewable materials (FHNW):
• Pyrolysis
• Activation
• Performance
• Physical and chemical characterization
Parameter screening
• DSC/TGA plus adsorption (UV 254)
• Upscaling to pilot (1 kg/h) to verify surface area,
porosity, hardness, density
Mid 2020 (FHNW):
Production of optimised GAK for long-term tests
GAC from sewage sludge
after pyrolysis
• Sewage sludge, CO2, 800°C
• Cherry pits, H2O, 1000°C

6. Renewable granular activated carbon(GAC)
TGA Analysis of pilot materials activated @ 900°C 10’:
• Sewage sludge GAC (SS) with 10-15% carbon content
• Cherry pit GAC (CP) with 90% carbon content
32
%
54
%
25
%
40
%
44
%
6%
0
%
20
%
40
%
60
%
80
%
100
%
dried
SS
CP-
dried
fraction
14% 14% 13%
92
%
90
%
87
%
85
%
86
%
86
%
3% 3% 5%
0
%
20
%
40
%
60
%
80
%
100
%
SS-
0%
stea
m
SS-
50%
steam
SS-
100%
steam
CP-
0%
stea
m
CP-
50%
steam
CP-
100%
steam
«anorganic» carbon in O2
«organic» carbon N2
inert
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7. Renewable granular activated carbon(GAC)
Sewage sludge GAC with higher density than reference
Cherry pit GAC with lower density than reference
300
0
250
0
200
0
150
0
100
0
500
0
7
cp
raw
cp
0%
stea
m
cp
50%
steam
cp
100%
steam
dried
SS
SS
0%
stea
m
SS
50%
steam
SS 100% NORIT
GAC
steam
true
density
[kg/m
3
]

8. Renewable granular activated carbon(GAC)
Reference experimentsinfullscalecolumns withconventionalGAC
Microbial characterization and quantificationvia metagenomics
 highermicrobialabundance inBAC columns compared tonormal filtermaterial
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9. Large scale demonstration ofammonium recovery
GOAL:nitrogen recoveryviahollowfibermembrane contactor
• Optimize process parameters
(temperature, pH, centrate flow)
• Determine KPI (area specific ammonia
mass transfer, absolute ammonia yield,
yield specific caustic soda and heat
consumption)
• Granulation tests, NPK(S) fertilizer
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10. P-recovery by thermochemical treatmentof
sewage sludge
GOAL:phosphorus recoveryviaPK-fertilizerproduction
Preparatorytrials finished in February2020
 Pilot plant isoperational
Autumn 2020: Lab test Calcination (FHNW)
Autumn 2020: Lab test Granulation(CTU)
Winter 2020/21: Pilot trials (CTU, FHNW)
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11. FOLLOW US
The consortium has receivedfunding from the
European Union’s Horizon 2020 research and
innovation program under grant agreement No.
776541.
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