Increased population, higher water flows and demands for stricter effluent limits are some of the challenges that Gryaab handles in the Nya Rya project.
The existing Rya WWTP in Gothenburg, Sweden, with 800 000 connected inhabitants (2021), is about to expand to a much larger WWTP with 1.35 million connected inhabitants in 2055. This is equivalent to an increase of the average influent flow from 4.5 cubic meter per second to 6.5 cubic meter per second. In addition to new water treatment processes this project also includes a new huge pumping station and considering a new tunnel for effluent wastewater. The project, called Nya Rya, started in 2021 and will be finalized in 2036.
The prerequisites are set: the most sustainable technology is to be chosen. So how do we decide what is most sustainable? By performing a full multicriteria analysis developed by Gryaab’s industrial phD student. Considering 16 different criteria, we will be able to make a conscious choise of process technology, that will last for a long period of time.
This year we investigate and design three different possible technical solutions, either on activated sludge, aerobic granular sludge or membrane biofilm reactors.
The investigations during the first year of the project, 2021, led to the decision to test three different technologies in pilot scale: