Jun 01, 2012
Combined technology alleviates water challengesBack
Engineering|Africa|Chutes|Consulting|Environment|Pipes|Resonant Environmental Technologies|Resonant Group|Resonant Water|System|Systems|Waste|Water|Africa|Russia|Chlorine-based Systems|Electricity Savings|Energy|Equipment|Inefficient Water Management|Less Electricity|Maintenance|Pipes|Potential Energy|Systems|Ultraviolet Disinfection Systems|Consulting Engineers|Environmental|Chris Laubscher|Marno Raath|Olof Vorster|Waste|Water|Aeration|Biofiltration|CW Technology|Wastewater Treatment
© Reuse this
Resonant Water is a subsidiary of environmental engi- neering company Resonant Environmental Technologies.
The CW technology can be beneficial to the South African and African water sectors in a number of ways, says Raath, noting that the technology combines the four main processes associated with wastewater treatment, namely sedimentation, aeration, biofiltration and activated sludge methods, one process.
After preliminary mechanical treatment (to separate sus- pended solids and sands), sewage is drawn into a mixing chamber, where it is mixed with the sludge liquid coming from an aerotank settler.
The mixture of sewage and sludge is drawn from the mixing chamber with a circulation pump and sent to the biofilter sprinkling system which comprises spouting chutes with outlet pipes and reflecting disks.
The water jets are then broken on the disks, irrigating the biofilter feed, after which the liquid leaving the biofilter is collected in a tray and delivered to the aeration zone of the aerotank settler by air-stripping towers.
“This is done using potential energy and, therefore, eliminates the need for blowers and aerators as well as the use of the return- activated sludge pumpstation and the waste-activated sludge pumpstation, which leads to significant electricity savings,” he adds.
Eliminating this equipment also decreases the system’s maintenance requirements and it requires less land space to function effectively, says Resonant Group marketing and business development director Olof Vorster.
Maintenance costs are further reduced owing to the technology, which uses ultraviolet disinfection systems instead of traditional chlorine-based systems.
“The system uses 25% less electricity, requires 30% less maintenance and saves more than 60% on land space, compared with conventional water treatment works, while delivering safe and odourless water,” he adds.
Further, Resonant Water states that the CW process is consistent, irrespective of the size of the plant, which makes skills transfer and the applicability of skills between different plants easier.
“As wastewater treatment plants are traditionally customised, there is little standardisation in this industry, creating difficulties when workers from one plant need to move to another. CW addresses this,” assures Raath.
The CW process was independently investigated by Dr Chris Laubscher from engineering consultancy Sizatech Consulting Engineers. “The CW process is extremely competitive compared with most known wastewater treatment processes, especially with regard to operational costs,” he says.
Laubscher adds: “The CW process has been found to deliver effluent capable of conforming to at least the general standards set out by the National Water Act, while most of the requirements of the special standards can also be met without adapting the current process.”
The technology was designed to limit heat exchange between the system and the environment. This is necessary as wastewater treatment is a biological process that makes use of microorganisms, which function better at a stable temperature.
“We recognised that this characteristic could also be beneficial in Africa, as the continent is subject to high temperatures,” says Raath.
The enclosing of the system also leads to greater efficiency, as the pathogens that are generated by the system mainly stay inside the plant, compared with conventional treatment systems, where mixers and aerators release pathogens into the air.
Another benefit of the enclosed system is that the sanitary zone, or the radius around the plant up to which one can build, is much smaller than with conventional plants, Vorster points out.
“Currently, the sanitation zone around conventional water treatment plants is 500 m in circumference, while this technology has a European rating of 16 m,” Raath adds.
The first local plant using this technology was commissioned at a game lodge outside Modimolle, in Limpopo, in November last year. The plant treats 7 500 ℓ/d of wastewater to produce drinking water and water for irrigation purposes.
Resonant Water aims to build a 3.4-million-litre-a-day plant and a 12.5-million-litre-a-day plant within the next two years.
Edited by: Chanel de Bruyn© Reuse this Comment Guidelines (150 word limit)
Other Water Engineering and Infrastructure News
Corrosive conditions in the African water treatment sector have created a high demand for hard-wearing, versatile materials, designed for enhanced safety, according to gratings, treads, pressed floors and handrails company Vital Engineering.
Recent Research Reports
Defence 2014: A review of South Africa's defence industry (PDF Report)
Creamer Media’s Defence 2014 report examines South Africa’s defence industry, with particular focus on the key participants in the sector, the innovations that have come out of the sector, local and export demand, South Africa’s controversial multibillion-rand...
Road and Rail 2014: A review of South Africa's road and rail infrastructure (PDF report)
Creamer Media’s Road and Rail 2014 report examines South Africa’s road and rail transport system, with particular focus on the size and state of the country’s road and rail network, the funding and maintenance of these respective networks, and the push to move road...
Real Economy Year Book 2014 (PDF Report)
This edition drills down into the performance and outlook for a variety of sectors, including automotive, construction, electricity, transport, steel, water, coal, gold, iron-ore and platinum.
Real Economy Insight: Automotive 2014 (PDF Report)
This four-page brief covers key developments in the automotive industry over the past 12 months, including an overview of South Africa’s automotive market, trade figures, production and the policies influencing the sector.
Real Economy Insight: Construction 2014 (PDF Report)
This five-page brief covers key developments in the construction industry over the past 12 months. It provides an overview of the sector and includes details of employment in the sector, infrastructure and municipal spending, as well as insight into companies’...
Real Economy Insight: Electricity 2014 (PDF Report)
This five-page brief covers key developments in the electricity industry over the past 12 months, including details of State-owned power utility Eskom’s generation activities, funding and tariffs, independent power producers and prospects for the sector.
This Week's Magazine
Integrated energy and chemical company Sasol has partnered with Unisa Graduate School of Business Leadership (SBL) professor and founder and CEO of PanAvest Partnership Dr Douglas Boateng to publish a series of books on executive supply chain management aimed at...
The World Wide Fund for Nature’s (WWF’s) 2014 Living Planet Index (LPI) indicates that there has been a 52% decline in vertebrate species since 1970. The Index tracked the trends of 10 000 discrete populations of over 3000 vertebrate species between 1970 and 2010.
Rwanda has joined a number of East African countries seeking to import electricity from Ethiopia as its demand grows. After it became apparent several generation project it is implementing will not come on stream early enough, now plans to import 400 MW from Ethiopia...
Metrorail’s first new passenger train will arrive in November next year, says Passenger Rail Agency of South Africa (PRASA) CEO Lucky Montana. “Next year we will be able to put our hands around the infrastructure and equipment we have been talking about for so long.”
The Competition Commission has launched an investigation into what it says are “price fixing, market division and collusive tendering in the market for the manufacture and supply of automotive components to original equipment manufacturers” (OEMs, or vehicle...
Next ArticleConstruction starts on Eastern Cape dam