Nereda is a
wastewater treatment
Wastewater treatment is a process used to remove contaminants from wastewater and convert it into an effluent that can be returned to the water cycle. Once returned to the water cycle, the effluent creates an acceptable impact on the environme ...
technology invented by
Mark van Loosdrecht
Mark van Loosdrecht (born 1959) is a Dutch professor in environmental biotechnology at Delft University of Technology. He was the creator of Nereda, a wastewater treatment technology developed by a cooperation between the Delft University of Techn ...
of the
Delft University of Technology
Delft University of Technology ( nl, Technische Universiteit Delft), also known as TU Delft, is the oldest and largest Dutch public technical university, located in Delft, Netherlands. As of 2022 it is ranked by QS World University Rankings among ...
in the Netherlands. The technology is based on
aerobic granulation
The biological treatment of wastewater in the sewage treatment plant is often accomplished using conventional activated sludge systems. These systems generally require large surface areas for treatment and biomass separation units due to the genera ...
and is a modification of the
activated sludge process
The activated sludge process is a type of biological wastewater treatment process for treating sewage or industrial wastewaters using aeration and a biological floc composed of bacteria and protozoa. It uses air (or oxygen) and microorganisms to ...
.
![Nereda WWTP Garmerwolde, the Netherlands](https://upload.wikimedia.org/wikipedia/commons/5/5a/Nereda_WWTP_Garmerwolde%2C_the_Netherlands.jpg)
Aerobic granular sludge can be formed by applying specific process conditions that favour slow growing organisms such as PAOs (polyphosphate accumulating organisms) and GAOs (glycogen accumulating organisms). Another key part of granulation is selective washing whereby slow settling floc-like sludge is discharged as waste sludge and faster settling biomass is retained. At the full-scale, the Nereda system consists of a cyclical process with three main cycle components or phases, namely: simultaneous fill and draw, aeration / reaction and settling. The aerobic granules form excellent settling properties allowing for higher biomass concentrations (8g/L), the non-use of secondary clarifiers and the exclusion of major sludge recycle pumping in the Nereda system – the result is a compact (reduced plant footprints), simple system that requires significantly less chemicals and energy when compared to conventional activated sludge (CAS) systems.
[http://saice.org.za/downloads/monthly_publications/2015/2015%20Civil%20Engineering%20June/#/58] The theory of this technology has proven to work in the field and currently more than 90 wastewater treatment plants worldwide are operational, under construction or under design, varying in size from 500 up to 2,400,000 person equivalent. The Nereda technology is an invention of the
Delft University of Technology
Delft University of Technology ( nl, Technische Universiteit Delft), also known as TU Delft, is the oldest and largest Dutch public technical university, located in Delft, Netherlands. As of 2022 it is ranked by QS World University Rankings among ...
and Engineering consultancy
Royal HaskoningDHV
Royal HaskoningDHV is an international, non-listed engineering consultancy firm with headquarters in Amersfoort, Netherlands. It has offices in 30 countries, employing 5,800 professionals worldwide.
Royal HaskoningDHV is active in aviation, build ...
.
The Nereda derives from the Greek word “Neraida”. Nereda was a water nymph and one of the daughters of
Nereus
In Greek mythology, Nereus ( ; ) was the eldest son of Pontus (the Sea) and Gaia (the Earth), with Pontus himself being a son of Gaia. Nereus and Doris became the parents of 50 daughters (the Nereids) and a son ( Nerites), with whom Nereus liv ...
, the wise and benevolent Greek god of the sea. In Greek mythology Nereda is linked with the terms “pure” and “immaculate”, a reference to the water quality produced by the new technology.
References
{{reflist, 30em
External links
Official website
Sewerage