R3WATER

Getting all the value from waste water

Removing pollutants is of course a priority at waste water treatment plants, yet there is a growing awareness that they could also act as production units, providing energy, nutrients and other valuable resources. Uwe Fortkamp and Klara Westling tell us about the R3 Water project’s work in developing innovative technologies to support the development of waste water treatment plants

The core function of a waste water treatment plant is to remove emissions and pollutants from waste water, yet they could potentially play a broader role, including in nutrient recovery, energy production and water re-use. Based at the Swedish Environmental Research Institute, Uwe Fortkamp is the Principal Investigator of the R3 Water project, an EC-backed initiative developing innovative solutions to support the development of waste water treatment plants. “We want to support the transition from being purely a treatment plant towards a production facility,” he explains. The aim is for plants not to focus solely on treating water and meeting quality thresholds, but also to develop usable products, covering three main areas. “One is re-using water. We are treating water, so why not re-use it?” points out Fortkamp. “The second is to recover valuables, we have looked at sludge treatment and phosphorous recovery. The third is resource efficiency – there is a strong focus on energy issues in the project, on using the incoming energy with the water in a positive way as well as being resource efficient and saving energy in each treatment step.”

WWTP Antwerp-Zuid

Re-using water

This research centres around modifying and upgrading existing waste water treatment plants with new solutions rather than creating an entirely new process. One aspect of this work is developing technologies to disinfect and monitor water for reclamation; while some treatment plants already do this, Klara Westling, project manager at IVL Swedish Environmental Research Institute says there is still scope for improvement. “With the technologies that we are

developing, we aim to ensure that the water system is much safer than it is today. At the moment, the drinking water supply can still get contaminated,” she stresses. Researchers are developing several different technologies, including an advanced online monitor for levels of micro-biological infectious pollutants in water. “These technologies are designed to monitor water quality, which is particularly important if you want to re-use it – a typical way of re-using water is in agriculture, for irrigation,” continues Klara.

Increasing the ratio of water reuse is one of the key priorities for the EC in the upcoming years. In this context, the online monitoring of microorganisms can provide

important benefits, including efficient production of reclaimed water

Nutrient recovery

A second major area of the project’s research relates to nutrient recovery. Sludge is a byproduct in the waste water treatment process, originating from both incoming particles as well as from microbiological sludge generated in the process; handling this sludge efficiently is an important issue for many waste water treatment plants. “This sludge is a cost factor for the plant. What we’re asking is – can we do something more with it? Can we produce value out of it?” continues Fortkamp. “Phosphorus is one target, and we are also looking at using a process called Hydrothermal Carbonization (HTC), which allows us to produce a biochar. This biochar could then be used for other purposes as well – for example, depending on how you operate the process and how the parameters are set, you might get a type of activated carbon.”

A number of countries prohibit the re-use of sludge in agriculture however, in which case it is often incinerated. Nutrients can again be recovered following this process. “When sludge is incinerated, ashes are produced, and it is possible to recover valuable nutrients from these ashes. The first target is to look for phosphorous, which would otherwise be lost if the ashes were put into landfill,” explains Fortkamp.

Depuradora d’Empuriabrava.

Location of R3water technologies at the WWTP.

Resource efficiency

Researchers are also developing techniques for resource efficiency, one aspect of which is looking at the operation of a waste water treatment plant as a whole. “One of our project partners has set up a model of a treatment plant to see how it performs. From there they can make recommendations on improving the operation through changes in the control system,” says Klara. “Another part of the project is the development of a model predictive control technology. This model learns from results gathered from sensors, which can then influence the overall settings in the control system.”

This means that the operation of the control system could potentially be modified and adapted in line with local circumstances. Data on key parameters like the flow-rate and quality of incoming water can be incorporated within the model, allowing staff to identify ways in which operational efficiency could be improved. “The model will help you to identify whether you need to increase pumping for instance, or the oxygen supply, or other variables,” explains Klara Westling, a scientist at the Swedish Environmental Research Institute who is coordinating the project alongside Fortkamp.

One area in a treatment plant where efficiency could be improved is in the aeration step, in which air is circulated to allow aerobic bio-degradation of pollutants, another topic that the project is addressing. “Up to 50 percent of the total energy demand in a treatment plant comes from the aeration step,” says Fortkamp. “The project is developing a technology which improves aeration efficiency by using fluidic oscillation to create microbubbles of air, to get a better transfer rate from the air into the water phase.”

This means that less energy would be required to pump air into the water, leading to cost and energy savings, which is always an important issue for waste water treatment plants. The technologies developed within the project are demonstrated at sites in Spain, Belgium and Sweden, chosen specifically to assess their effectiveness in different climates and with different levels of water availability. “In Southern Europe the climate is quite warm and water scarcity is an increasingly prominent issue. In central Europe, the climate is quite temperate, then it’s colder in northern Europe,” says Fortkamp. The current focus is on demonstrating the technologies developed in the project, but if they prove effective then Fortkamp says there are wider commercial opportunities, beyond the existing sites. “We are starting with Europe, and at waste water treatment in a number of countries, but we have also looked into operational requirements in Asia, in particular China,” he outlines.

While the project’s research is exploratory in nature, and not all of these technologies and solutions being developed will reach the market, Fortkamp is confident that their research will have a wider impact. “It varies really across the different technologies, but certainly the aim is to get some of them to the market. Hopefully several more will be commercially available at a later stage, after additional development work,” he says.

Full Project Title

Reuse of water, Recovery of valuables and Resource efficiency in urban wastewater treatment (R3Water)

Project Objectives

The main objective of R3 Water is to support the transition from an urban wastewater treatment plant to a production unit of different valuables by demonstrating new solutions to address main challenges. Objectives are to: Demonstrate technologies and solutions for increased efficiency in Urban wastewater treatment. / Demonstration of innovative wastewater technologies that enable reuse of water and recovery of valuables such as nutrients Facilitate market uptake in the European Union and on a global market.

Project Funding

This project has received funding from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement No 619093.

Contact Details

IVL Swedish Environmental Research Institute Vallhallavaegen 81 11427 Stockhom, Sweden M.Sc. Uwe Fortkamp, T: +46 (0) 8598 56304 E: uwe.fortkamp@ivl.se M.Sc. Klara Westling T: +46 (0) 8598 56431 E: klara.westling@ivl.se W: http://r3water.eu/

M.Sc. Klara Westling M.Sc. Uwe Fortkamp

M.Sc. Klara Westling, has a degree in Environmental and Aquatic Engineering and is project manager at IVL Swedish Environmental Research Institute, has more than 10 years of experience of working with process operation, optimisation and evaluation of innovative wastewater treatment technologies for both municipal and industrial wastewaters. M.Sc. Uwe Fortkamp, has a degree in Process Engineering, and is assistant Unit director at IVL Swedish Environmental Research Institute. He has more than 20 years’ experience of innovations for resource efficient processes including recovery and valorisation of water and resources, and is project leader including EU projects.