Home Home
Please choose your language:
domestic wastewater treatment plants
method ZebraFilter®
pilot plant
purification of lakes
business partners
press reports
contact & route + map
press reports

Dreissena polymorpha for water filtration
the bivalve reactor

Berlin . For the United Nations it's one of the dangerous alien (neozoon) species on earth. But for Barbara Ral it's a source of income. Dreissena polymorpha , a bivalve mussel waring characteristic zebra stripes, is able to adapt to foreign ecosystems and may cause damage there. If on the other hand this animal is held and bred under controlled conditions in aquaculture, it may be used to remove bacteria and other pollutants from water. It turns wastewater into bathing water. The idea of Barbara, to take advantage of the activity of the zebramussel, was developed at university. “I conducted a research project aiming to remove bacteria from water using these mussels,” she says. “This was successful, I decided bring this system to the market and filed a patent and a trademark called ZebraFilter®.”

The use of Dreissena for the purification of water works without external energy supply, because the mussels “feed on the dirt”, they do not pollute anything and it's a low-cost method compared to other ways of water disinfection. A container to filter the wastewater amount of 100 people is about one cubic meter in size and contains 2000 to 3000 mussels. Meanwhile, “ZebraFilter®” is a registered trademark and also the name of Barbara's own company.

Thanks to the experience in wastewater treatment, the company also offers advice on suitable methods for water treatment in special cases and it procures business partners for special purification systems. Amongst her clients is a local authority in the vicinity of Munich/Germany. “In the future I also want to sell my ZebraFilter in Russia and the Ukrain, the country of origin of Dreissena .”


sabato sera , Bologna / Italy , 09.10.2004
author: Ms Lorena Mirandola; translated by Ral