Final thesis in dual study programme at HUBER SE: HUBER Pile Cloth Media Filter RotaFilt® to meet the requirements of Norway's future wastewater directive
I began my dual Bachelor's degree in Biological and Environmental Process Engineering at HUBER and the East Bavarian University of Applied Sciences in Amberg-Weiden in September 2021. The degree programme focuses primarily on natural sciences and engineering subjects such as fluid mechanics, mechanical and thermal process engineering, and water and wastewater treatment. In addition to theory, several practical projects must also be completed during the study-free periods.
Practical experience at the HUBER Technology Centre
I had the advantage of being able to gain practical experience at the HUBER Technology Centre as a dual student. I supported the product managers with various projects, familiarised myself with the machines through a series of tests with different demonstration plants, and gained new insights. The 3.5-year degree programme concludes with a bachelor's thesis. The project for this thesis took me to Norway, more specifically to Øystese.
A picturesque destination and a technical challenge
Øystese is a small town with around 2,000 inhabitants in south-western Norway. It is located directly on the Hardangerfjord, Norway's second-longest fjord, which is surrounded by large green spaces, mountains and glaciers.
Norway's new wastewater directive requires action
As Norway wants to protect its environment even better, a new wastewater directive has been drawn up that affects the sewage treatment plant I visited.
Previous plant operation without biological treatment stage
Previously, wastewater from the treatment plant, which is designed for a population equivalent (PE) of 10,000, first passed through the mechanical treatment stage, a HUBER Micro Strainer ROTAMAT® Ro9 500, then a HUBER Circular Grit Trap HRSF 2 and finally a flotation unit. As is common for many wastewater treatment plants in Norway, no biological treatment stage has been used to date.
New requirements necessitate retrofitting
The new Wastewater Directive will tighten the limits for wastewater discharge in the future, and the current effluent values of the wastewater treatment plant show that compliance with these values is not possible with the technology currently installed on site. According to a market analysis by our colleagues at HUBER Technology Nordic, several hundred wastewater treatment plants in Norway will have to retrofit their machinery and plants in order to comply with the new regulations.
Visit to the Øystese wastewater treatment plant
As part of a project, I travelled to Norway in March 2024. I visited the Øystese wastewater treatment plant for the first time and presented the HUBER product portfolio to the local staff. We then agreed that a series of tests with the HUBER Pile Cloth Media Filter RotaFilt® should be carried out on site to find out whether the RotaFilt® is a suitable technology for complying with future limit values.
Test series with the HUBER Pile Cloth Media Filter RotaFilt® on site
At the end of August, the time had come. I boarded the plane to Norway and made my way to Øystese. Meanwhile, a RotaFilt® demonstration machine was also on its way north. After our Norwegian colleagues and I had assembled the machine and prepared it for the test series, I began varying the amount of coagulant and flocculant in the laboratory to produce flocs and transferred the best result to the demonstration plant.
Very good results
The pile fabric used on the cloth filter was able to reliably retain the flocs. In the on-site laboratory, I sampled the inflows and outflows of the wastewater treatment plant. The evaluation of the results shows that the HUBER Pile Cloth Media Filter RotaFilt® can comply with the future limit values for COD, BOD and phosphate. Very good separation performance was also achieved for filterable solids and turbidity across a wide throughput range.
Foundation for future solutions in Norway
The series of tests were the basis for adapting the plant, and our colleagues at HUBER Technology Nordic received training in the new machine technology. This demonstrates to the Norwegian market that our products can make many wastewater treatment plants in Norway fit for the future again.
Experiencing nature in my free time
In addition to the test series, I had the opportunity to hike to the famous Trolltunga rock formation at the weekend. I enjoyed beautiful views of mountains, glaciers, waterfalls and fjords.
