Technology suitable for S Africa context

In the quest to mitigate water supply difficulties that have been prevalent in South Africa in the past few years, international engineering consultancy and technology provider Royal HaskoningDHV says its range of innovative wastewater treatment and smart water solutions is relevant in the context.

“Energy savings, optimisation and efficiency are currently issues of concern in South Africa and our smart water technologies are exciting and relevant to what the country needs,” says Royal HaskoningDHV South Africa advisory group director Sheilla De Carvalho.

She explains that two products, namely the Nereda technology and Aquasuite, have strong relevance to South Africa’s current water challenges and issues.

Nereda

She points out that the Nereda technology, a wastewater treatment solution, was first thought of by two professors 22 years ago. Since then, through partnerships, the first full domestic plant was pioneered in South Africa. “It is exciting for South Africans to showcase the country’s innovative, driven and ambitious spirit embodied in the Nereda technology.”

Royal HaskoningDHV water and wastewater process engineer Joana Doutor explains that Nereda is an innovative biological wastewater treatment that purifies sewage using aerobic granular biomass.

“Contrary to conventional activated sludge technologies, the Nereda purifying bacteria concentrate naturally into compact aerobic granules. These granules are micro-reactors themselves, enabling all biological processes to take place in the granular biomass and do not require different physical compartments.”

Doutor says this characteristic of the granular biomass results in Nereda being capable of producing excellent final effluent quality. In addition, these granules are dense and therefore settle very fast. The granules allow for simultaneous biological removal of carbon, nitrogen and phosphorous compounds, making the operation chemical-free.

The Nereda technology combines the important key-benefits of operational and energy savings with high effluent quality standards. “Nereda solutions can have a footprint that is four times smaller when compared with conventional technologies. It also has significantly lower energy consumption and produces high effluent quality.”

Doutor adds that Nereda is a one-tank concept, which means that all processes happen in one reactor that works in batches/cycles. She says that Nereda is easy to operate, requires less mechanical equipment and allows compact civil structures, resulting in an improved environmental construction profile.

Operational savings on Nereda are substantial with Doutor estimating that as much as 30% can be saved in energy costs. Moreover, owing to the technology’s smaller carbon footprint, capital savings in terms of the initial investment in the technology can be between 20% and 30%.

“Currently, there are two fully operational Nereda plants in the Western Cape, with a third plant under way in Johannesburg, awaiting commissioning and start-up in 2017.” Doutor says that the third plant is a retrofit installation to help the existing wastewater treatment plant perform better.

Aquasuite

Another smart water intelligent solution for the entire water chain offered by the company is Aquasuite. The product comes in many different forms, each with different water sector requirements. It is easy to integrate on existing automated water and wastewater plants as well as water networks.

Royal HaskoningDHV electronics engineer Tendai Mukwati explains two key Aquasuite products that are relevant to South Africa’s water challenges: Aquasuite OPIR and Aquasuite Pure.

Mukwati explains Aquasuite to be a software platform for the water sector focused on reliable prediction of supply and demand supported by smart controls. She notes that, over time, with innovation and technological advances, the smart technology has evolved into real-time prediction. For drinking water supply, Aquasuite OPIR forecasts the consumption for the upcoming 48 hours, based on the supply area’s demand patterns. Equipped with this real-time forecasting information, optimisation in the control of the volume and pressure in the entire water system can be achieved. A stable and efficient process performance, optimal water quality and minimal energy consumption was noted to be the result.

She says optimising water management is the focus of Aquasuite smart water solutions, and that these solutions can help to mitigate the effects of the water crisis South Africa has been experiencing. Mukwati further remarks that the water shortages the country has been experiencing are not only due to drought, commenting that a lot of water is lost due to pipe bursts and water leaks. Aquasuite OPIR can alert to deviations caused by pipe bursts. She cites this as a significant contributor to addressing the nonrevenue water challenges that are widespread in the country.

“It will also impact positively on clients, decreasing the need for big spend in terms of new build water infrastructure, optimising the use of the existing assets in the water network, ensuring water availability,” notes Mukwati.