Up to 50 million litres of drinking water per day: microfiltration at Constance waterworks modernised with three HUBER Disc Filter RoDisc®

Lake Constance, with a water surface of about 536 km² the largest lake in Germany and the largest freshwater reservoir in Central Europe, has been used for the drinking water supply of the city of Constance for more than 110 years. Due to the already excellent quality of Lake Constance water, the waterworks can provide up to 50 million litres of drinking water for the Constance region every day with comparatively few treatment steps.

Excellent drinking water quality through microfiltration, ozonation and sand filters

The raw water is pumped out of Lake Constance from a depth of 40 metres. First, all coarse pollutants are removed by microfiltration and then any germs are killed by treatment with ozone. In the final step, the water flows through a sand filter that retains all remaining particles. Afterwards, the excellent drinking water can be distributed through the water network in the city and region.

Use of reliable and innovative HUBER Disc Filter RoDisc^® technology

A challenge in water treatment at Lake Constance are the approx. 50 µm small larvae of the Quagga mussel. The mussel, which originates from the Black Sea region, was first detected in Lake Constance in 2016 and has been spreading rapidly since then. In order to prevent a high cleaning effort in the downstream systems, it must be ensured that the mussel larvae do not impair the operation of the waterworks. To ensure this in the long term, the now 50-year-old drum filters are replaced by reliable and innovative HUBER Disc Filter RoDisc^® units.

HUBER SE is responsible for the complete renewal of the micro-screening system. Together with the company Sülzle Kopf GmbH from Sulz am Neckar, the machines will be replaced step by step from the beginning of 2022 to mid-2023 to ensure that the drinking water supply remains continuously guaranteed. In the course of this, HUBER will supply three size 8 RoDisc^® disc filters. Equipped with a special filter fabric, the disc filters reliably remove particles > 20 µm and thus all mussel larvae.

The HUBER Disc Filter RoDisc^® 8 consists of eight filter discs each, the wastewater flowing through the screen from inside to outside by gravity. If the permeability of the filter fabric decreases due to retained particles, the machine switches on automatically. Then the filter discs rotate and are cleaned by means of a high-pressure pump. As the filtrate from the machine itself can be used for cleaning, no additional fresh water connection to the machine is necessary.