Innovative Norwegian technology from Guard Automation optimises wastewater treatment

”Thousands of litres of sewage are treated here every hour,” says Roger Engen, head of water and wastewater in Modum Municipality.

Engen explains that the sewage goes through a series of processes before the water is released back into nature. The goal is to remove environmentally harmful substances and convert sewage into water that is as clean as possible.

”To achieve that, we use large amounts of chemicals that, among other things, bind to environmentally harmful phosphorus,” Engen explains.

”But how many chemicals should be added to the treatment plant at any given time? That is the challenge we have been working to solve for many years, and which we are now ready to roll out across municipalities in Norway,” says Jon Egil Ek of Guard Automation.

The company specialises in automation and system integration, assisting nearly 40 per cent of Norwegian municipalities with systems related to critical infrastructure.

Cleaner water with fewer chemicals

Ek explains that factors such as snowmelt, time of day and precipitation have a major impact on how many chemicals should actually be used. In professional terminology this is called extraneous water.

”Our new solution is called Guard Treat Smart. Simply put, it is a predictive model that takes into account the amount of extraneous water in treatment plants to optimise the chemical dosage. If there has been a lot of precipitation and snowmelt, the amount of extraneous water is large and the concentration of sewage is lower than normal. In that case fewer chemicals are required,” he explains.

Preliminary results from the treatment plant in Modum show that the water has become cleaner with fewer chemicals.

”The pilot has demonstrated an improved purification rate over time, with an approximately 20 per cent reduction in chemical consumption. However, we expect the results to improve even further as the model trains itself with new data.”

This is supported by the head of water and wastewater in Modum Municipality:

”The new solution gives us cleaner water with fewer chemicals. It also saves us money, and the technology has made it easier to operate the plant,” says Engen.

He says that chemical dosing has been a manual process until now.

”It has been educated guesswork. And it is clear that with the help of new technology this can be done better. For example, the treatment plant is unstaffed on weekends,” Engen explains, adding that the municipality spends hundreds of thousands of kroner annually on chemicals.

More informed decisions

Ek says that the technology also provides better insight into matters such as the composition of the wastewater, pH levels and retention time in the treatment plant.

”Continuous measurements of the proportion of extraneous water can be used to analyse the development of the condition of the piping network over time, measure the effect of improvement measures, and not least serve as a basis for decision-making on whether to invest in expanded treatment capacity or pipe network upgrades,” he says.

In sum, the technology provides crucial information to ensure that treatment plants are operated within applicable regulations and specifications, without the installation of additional sensors.

Extensive development with virtual tests

Guard started developing the solution in October 2021. The company utilised empirical data from a wide selection of treatment plants across Norway, conducting advanced data analyses of the process variables of the plants and their correlation with external factors such as meteorological, hydrological and demographic data, as well as time, location and season. Based on this, a cloud-based and adaptive model for operational optimisation was constructed.

”The virtual tests have been important in the development and validation of the technology. We gathered real data from ten different treatment plants, each with its own characteristics, and ran the technology in shadow mode. This means we could see how the technology would have controlled the dosage, without it actually being done. These tests have taught us a lot and shown that we can significantly reduce chemical usage,” says Ek.

He believes the technology will mean a lot for how wastewater treatment plants in Norway are operated.

”The solution makes operations simpler, more cost-effective, and reduces environmental impact through both reduced chemical usage and an enhanced purification rate. This is a game changer for how treatment plants in Norway are operated,” concludes Jon Egil Ek of Guard Automation.