A new start-up enables innovative wastewater treatment

The Belgian nuclear research centre SCK CEN is hidden in the forests of Mol (Belgium). Experts from all over the world work together here on innovative nuclear solutions to societal challenges: from the decommissioning of installations to effectively fighting cancer through the production of medical radioisotopes.


It is here that we find Kristof Gladinez. He recently founded the company Olpas: this start-up wants to revolutionise the water purification sector with an entirely new designed sensor. Next to him is Joris Van den Bosch. The business developer at SCK CEN encouraged the young engineer to bring this sensor to the market.



"You are a researcher at the nuclear research centre SCK CEN, but you have invented something for water purification. Tell me about it"


Gladinez (Olpas): "Since my graduation as an engineer, I have been working on the MYRRHA project at SCK CEN. I focused specifically on lead bismuth, a new coolant that will cool the reactor core of the MYRRHA research infrastructure. A peculiar characteristic of this coolant is that it can be polluted by small oxidation particles that can form in it. Therefore, there was a need for a sensor to detect the contamination in this fluid. I also have a doctorate in this field. But such sensors do not exist yet."


Van den Bosch (SCK CEN): "Using liquid metal as an innovative coolant, as is the case with MYRRHA, obviously has major advantages. Think, for example, of the very high thermal conductivity and the very high boiling point. In addition, liquid metal also provides a wide range of issues that require a different solution than is typically the case when using traditional coolants such as water or thermal oils. Within the R&D developments around MYRRHA, this has led to research into seals, flanges, valves, pumps, new materials and, of necessity, innovative sensors. These sensors must be able to carry out the required accurate measurements and, at the same time, be able to withstand the extreme conditions in which they have to be used. Lead-bismuth is more or less corrosive to most types of steel."

"And so you decided to make such a sensor yourself?"

Gladinez: "During my PhD research, I realised the importance of a reliable sensor for future nuclear applications. That is why I started developing it. Now, two years later, the results are promising and we can see the great advantages of this sensor compared to other measurement methods.

Traditional methods that measure impurities in a liquid do so 'by sight'. A light source is placed in the liquid and a sensor looks to see how much light is still visible or reflecting a little further down the liquid. The incident light on the sensor determines the contamination of the liquid. Suppose you use this method in white or yellow lemonade: the transparency of both liquids will be completely different, while they probably contain the same amount of impurities. Even if you test this with different types of wastewater, you will get different results depending on the nature of the impurities in the water. Other methods without these drawbacks, such as measurements based on microwaves, are very complex and therefore far too expensive to apply everywhere in a flexible way. So we had to find a new solution, and we found it in the use of ultrasonic signals. This technique is similar to its optical counterpart: one sends out a signal and looks a little further into the liquid to see how much of that signal has been received. However, I found a solution that works with the echo that is sent back. You can compare it to an ultrasound during pregnancy: here you also look at the signal that comes back. The gynaecologist's equipment then makes an image of the baby. We use the echo of the signal to determine an image of the impurities or solids in a fluid."


"Why is this method better and such an important step for wastewater treatment?"

Gladinez: "Currently, impurities or solids in water treatment are best measured by taking a sample of the water, leaking that sample through a filter and then weighing the weight of the contaminated filter. This method is frequently used in large wastewater treatment plants for domestic wastewater.

Of course, such a measurement takes time, sometimes up to 24 hours per sample. This makes it impossible to quickly follow up and adjust the purification process. For water purification to be efficient, it is important that we measure correctly and know continuously how well the purification process is working. With our ultrasonic sensors, we can do this quickly and reliably."

"Currently, an accurate measurement of impurities in wastewater takes up to 24 hours. Our sensors do this measurement immediately."

"Are there still a lot of efficiency gains to be made in water treatment?"


Gladinez: "Pure water is of great importance to our health and the environment, and is indispensable for important processes in the food or pharmaceutical industries. There are therefore very strict rules that water must meet before it can be consumed or disposed of in nature, for example.

When purifying wastewater, the water goes through a whole series of steps in order to meet these strict requirements. These range from aeration and settling of activated sludge to filtration with very fine membranes. All these steps cost a lot of energy.

Aquafin, the company responsible for water treatment in Flanders, consumes approximately 290 GWh of energy (Energy Barometer Flanders, VEB, 2016), which corresponds to the consumption of almost 20.000 households! It is clear that every efficiency gain in this sector means a net gain for our environment and climate.

Aquafin, the company responsible for water treatment in Flanders, consumes approximately 290 GWh of energy, which corresponds to the consumption of almost 20.000 households! It is clear that every efficiency gain in this sector means a net gain for our environment and climate.

A new evolution in water purification is also to purify directly at the polluter and to reuse the wastewater as much as possible. More and more farms have their own water purification and factories purify their own water and reuse it in their processes. There are specialised installations for this purpose that can hardly be compared with the large communal water purification installations. The focus here is also on the removal of very specific substances, such as nitrogen at chicken farms or PVC pellets at a chemical plant. Often, this specialised water treatment fits into a container and is controlled remotely. It is necessary to be able to measure every small change in order for the process to run smoothly: a perfect application for the Olpas sensors."

"And now you are going to build a company around it?


Gladinez: "That's right. SCK CEN was very enthusiastic about my project, but wastewater treatment does not fit within the range of applications of SCK CEN. That is why I decided to set up a new company.


Van den Bosch: "This does not change the fact that SCK CEN in the meantime remains a good and interested discussion partner. And who knows, maybe some cross-pollination will be possible in the future."

Olpas technology could also be used to measure high concentrations of sludge in the dredging world or to check whether there isn't too much sediment in wine.

"What are the future plans for Olpas?"


Gladinez: "Currently we are with 2 people, my co-founder Jo Wouters and I, and our sensors are being built. This is done in Belgium, by the way. During our research, we were repeatedly pleasantly surprised by the expertise in high-tech development that is available here.

In this first phase, we are focusing on wasterwater treatment, but we feel a lot of interest from other sectors. For example, our technology could also be used to measure high concentrations of sludge in the dredging industry or to check whether there is too much sediment in wine. We also see possibilities in the chemical sector or even in medical processes. Certainly when we have fully developed the technology to measure through steel tubes, we can make a breakthrough there too.”


Van den Bosch: "We believe in the ambitions of Olpas. We wish the founders every success and tremendous growth."