Webinar 4: Wastewater Treatment

Talking about sludge

Which wastewater treatment solutions could be useful for the MENA region? The participants of this webinar got their hands dirty and honed in on various ideas.

Although waste solid water treatment is far from a new process in itself, new technologies to optimize the process are still being developed. “The conventional technologies have their downsides”, explained Dr Sjoerd Kerstens, Global Leading Professional – Water & Wastewater Technology and Resource Recovery at Royal Haskoning. “They require a significant footprint, they have high energy and chemical consumption requirements, and their construction and operation are quite complex.” Royal Haskoning is looking for solutions where infrastructures take up less space, consume less energy and are less complex. In collaboration with Mark van Loosdrecht, from the TU Delft, the Netherlands, Royal Haskoning is now introducing the Nereda technology. Nereda is an aerobic granular sludge technology which saves 50% on energy costs while removing nitrogen and phosphorus. The key to Nereda is that all processes take place in one reactor, where water is pumped in at the bottom and drawn out at the top. Besides the advantages of a smaller footprint and less energy consumption, Nereda involves minimal to no usage of chemicals and comes with smart software that ensures tailor-made treatment for each batch.

Dr Kerstens also mentioned Kaumera, a raw material that can be recovered from Nereda sludge. This extraction technique was developed in partnership with Delft University of Technology. Kaumera has several applications, including as a coating agent for fertilizers and as an absorption agent (for instance, in diapers). Also, although the research on this is still ongoing, Kaumera could be used for bio-nanocomposite materials, which have been known to have fire-retardant properties.

Solid waste and sanitation

Next, all participants divided themselves into three breakout groups. The first session dealt with Waste Solid Water Treatment, in which chemical engineer Mohamad Mahamid, external project manager, Aqaba Water Co. and responsible for five treatment plants in the south of Jordan, talked about the major challenge solid waste is posing as a by-product of water treatment plants. The treatment of sludge is expensive, as is its transportation to a different location. Also, sludge is difficult to dispose of, because of its negative impact on the environment. Mr Mahamid discussed many techniques to treat the sludge and presented a solution to reduce costs: “De-centralize water treatment plants to reduce transportation costs. But separate the sludge treatment lines from the water treatment plants and transport them to a centralized sludge treatment facility. In this central facility, the sludge can be converted to methane gas and energy.”

‘Separate the sludge treatment lines from the water treatment plants and transport them to a centralized sludge treatment facility.’

In the Sanitation breakout session led by engineer Stefanie Stubbé (Royal Haskoning BV), participants discussed the problems they were facing in their respective countries on this issue. For this part of the session, Dr Stubbé used Mentimeter, an interactive tool to gather opinions and issues using questions which the participants could answer by voting. As it turned out, the main problems participants faced in their respective countries ranged from financial limitations to lack of infrastructure and lack of awareness. Dr Stubbé then talked about a project in the Jordan Valley and how they approached certain challenges. In this approach, a challenge each time was approached by looking at what the problem was exactly, what goals do we want to achieve and how do we make this happen? Stakeholder participation proved to be a successful element of this project, and it certainly seems that other countries could strongly benefit from engaging stakeholders when trying to overcome certain barriers.

Desalination as an alternative

The breakout session on Desalination took a slightly different approach to the subject of wastewater treatment. Dr Sergio Salinas Rodríguez, Associate Professor at IHE Delft, discussed desalination of water as an alternative to alleviate water stress, especially in Africa and the Middle East. These regions rely heavily on the desalination of sea water, brackish water and even wastewater for different applications, such as drinking water, industrial applications or the re-use of water for agricultural activities. One particularly striking figure was mentioned: desalinating 1,000 litres of water costs less than one dollar, which is cheaper than buying a bottle of water from the kiosk. One of the big challenges in the region is building enough desalination capacity. IHE Delft is very interested in working together with local institutions to try to improve knowledge and research in the water sector.

During the final plenary discussion, participants were certainly interested in the technologies and solutions presented to deal with this issue. The session drew to a close, leaving more than enough food for thought.

You can watch the entire webinar here (only for registered Holland Alumni).

One participant’s reaction

‘Major challenges remain’

“Major challenges remain, for instance in regard to de-centralizing water treatment plants. Several countries in the MENA-region currently place central plants far away from cities, because of the problem of bad odour. Also, there’s currently not enough know-how in the region to properly operate de-centralized plants in cities.”