Nereda is a

wastewater treatment Wastewater treatment is a process which removes and eliminates contaminants from wastewater. It thus converts it into an effluent that can be returned to the water cycle. Once back in the water cycle, the effluent creates an acceptable impact on ...

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 The Delft University of Technology (TU Delft; ) is the oldest and largest Dutch public university, public Institute of technology, technical university, located in Delft, Netherlands. It specializes in engineering, technology, computing, design, a ...

in the Netherlands. The technology is based on aerobic granulation 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 is one of several biological wastewater tr ...

. 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 (8 g/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. 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 2,4 million person equivalent. The Nereda technology is an invention of the

and Engineering consultancy

Royal HaskoningDHV Haskoning, formerly known as Royal HaskoningDHV, is an international, non-listed engineering consultancy firm with headquarters in Amersfoort, Netherlands. It has offices in 30 countries, employing more than 6000 professionals worldwide. Haskon ...

. 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 ...

, 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

See also

References

External links