21 Feb 2020

How Nereda maintains its efficiency in hot countries, where average dry weather flow is a consideration

Bacteria in traditional wastewater treatment systems tend to function best within a quite specific temperature range. In cooler environments, bacteria still function but are inclined to do so more slowly. In warmer temperatures, there is a danger that they cease to function completely. Nereda® technology is a revolutionary biological wastewater system that uses aerobic granular biomass technology to purify water without chemicals. The Nereda process can function successfully in a wide variety of different temperature conditions, which makes it suitable for operating treatment plants all around the world. Its ability to monitor temperature and dry weather flow is critical, in order to optimise its performance and ensure consistent quality of output.

Although the technology was perfected in its country of origin, The Netherlands, a number of Nereda wastewater treatment plants are located in much hotter regions including Southern Europe, North and South America, Asia, Australia and South Africa. The heat increases biological growth rates, which benefits the development of granular sludge in the Nereda process.

Low average dry weather flow

Higher temperatures can easily be accommodated by Nereda technology. Low average dry weather flow is also a big consideration in regions of lower rainfall, such as South Africa. Fortunately, a key advantage of the Nereda process is its flexibility and its ability to adjust to any operable parameters. The design of each plant can be tailored to specific environmental conditions and requirements. The Nereda Controller uses patented technology to continuously monitor and analyse data in order to optimise and maximise a plant’s efficiency, even in regions of exceptionally low average dry weather flow.

Re-use, recycle

In regions of low rainfall and high temperatures all year round, wastewater is seen as a valuable commodity which must be preserved and re-used wherever possible. In this era of increased urbanisation and soaring populations, alleviating water shortages is an ongoing challenge. Reclaiming wastewater should be a priority, to free up freshwater for domestic use and to improve the quality of the effluent entering rivers.

The first Nereda plant to open in Australia, at Kingaroy in Queensland, not only effectively processes the community’s wastewater, it also re-uses up to 50% of the effluent produced for irrigating the local golf course and sports fields. Similarly, at Gansbaai in South Africa, the effluent produced by the Nereda process there is used to irrigate the surrounding areas.

Low odour solution

In some hotter areas, Nereda technology’s proven track record in reducing odours from the wastewater treatment process has been a major factor in its being selected as a solution, particularly in areas where the plants are located close to local populations. This was certainly the case in Rio de Janeiro, Brazil, where the Nereda plant has had to deal with large population increase and also has to operate in extremely humid conditions. Again, owing to the patented Nereda Controller technology, any issues related to higher temperatures can easily and swiftly be identified and controlled.

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