In our world, the availability of clean water
is an ever-growing challenge.
Urbanization and population growth
put a strain on land usage and the environment.
Water quality is in jeopardy
and treatment costs are rising.
Conventional water treatment 
with activated sludge
has been a tried and tested method
for over 100 years.
However, it has significant downsides,
such as high chemical and energy consumption
and poor settling sludge demanding large clarifiers,
resulting in a large installation footprint.
In the 1990’s, a professor
at Delft University of Technology
took on the challenge of designing
the ideal water treatment technology.
This resulted in the development
of Nereda Technology.
It can be applied in new plants
but also used to retrofit existing ones.
The core of Nereda technology
is a unique aerobic granular sludge.
All biological treatment occurs
within the granules
and in one tank, without the need 
for energy consuming mixers,
pumps, clarifiers, 
or complex moving decanters.
Nereda wastewater treatment works in batches,
consisting of three phases:
The anaerobic fill and decant phase:
Wastewater is introduced
from the bottom of the reactor
in a plug flow that pushes out
the treated effluent from the previous batch
from the top of the reactor
using a fix decanter.
Organic pollutants in the wastewater
penetrate into the granules
and are partly transferred
into storage biopolymers,
while phosphate is released
to the water phase.
In the aerobic phase 
the granular sludge is aerated,
the released phosphate is taken up
by the granules
and biodegradable components are oxidised.
Phosphor gets removed with the excess sludge.
Ammonium in the wastewater 
is oxidised to nitrate
on the outside of the granule.
Bacteria deeper in the granule
use the stored organics and biopolymers
to convert nitrate into nitrogen gas.
After this purification step, 
the granular sludge settles
to the bottom of the tank
and is then ready to receive a new batch.
Thanks to the granules,
settling takes place within minutes
compared to over one hour in conventional
activated sludge processes and SBRs.
Excess sludge contains biopolymers
that can be harvested and used
as a sustainable resource 
for numerous agricultural, industrial
and construction applications.
The benefits of Nereda Technology are profound:
 
Excellent effluent quality
Easy operation and maintenance
Significant savings in investment, 
energy and chemicals
A footprint up to four times smaller
Existing tanks can often be retrofitted 
to Nereda
doubling capacity 
and improving treated water quality
Phosphate and biopolymers
can be recovered as sustainable  resources
Nereda, a proven technology
that meets tomorrow’s challenges
in wastewater treatment.
