Carex of Sweden AB is a Swedish company with cutting-edge expertise in biological total solutions for individual wastewater and of contaminated water and soil recovery.

Our expertise is based on 100 years of combined interdisciplinary knowledge of processes in aquatic ecosystems, closed food webs, microbial cycles and plant physiology.


Pollution from individual sewers contributes to eutrophication of water systems and eventually the sea. Insufficiently purified sewerage destroys the already shrinking groundwater resources. At the same time, more than 2.5 billion people lack basic sanitation. Every third person on earth does not have access to a toilet. Without clean water it is impossible for communities to rise from poverty.

Therefore, we are obliged to convert invaluable international experiences from water projects and applied research into simple but robust solutions.

Carex of Sweden creates the conditions for continuous development of solutions for all societies. Our asset is people having interdisciplinary knowledge and a global vision.

Our business has its roots in an extensive wealth of practical experience and applied research, all stemming from a person from Lund, Stanislaw Lazarek. His scientific work has focused on microbial processes around the biofilm in water. He has researched the mechanisms causing eutrophication of lakes in Poland and Japan as well as in coastal lakes in South Africa. He has also studied acidified and oligotrophic lakes in Sweden, USA, Canada, Italy, England and France.

Dr. Stanislaw Lazarek

The original TreeWell concepts that have been developed by Dr. Stanilslaw Lazarek for more than 30 years (PhD in Marine Ecosystems, University of Lund, 1983), were already awarded a gold medal in 1997, at the World Innovation Exhibition in Brussels.

Dr. Stanislaw Lazarek has, since the early 1980s, worked together with colleagues in Poland, France, Italy, South Africa, USA and Canada.

Stanislaw is regarded as one of the world's leading scientists in the field of decentralised small-scale and biological treatment of sewage.

Carex of Sweden has a close cooperation with Dr. Stanislaw Lazarek.