Käthe Seidel

Käthe Seidel (1907-1990) was a German botanist. Seidel was the first researcher to incorporate vegetation into wastewater treatment wetlands, beginning in the 1950s. She was nicknamed "Bulrush Kate" ("Die Binzen Kaethe") for her use of the common bulrush, Schoenoplectus lacustris. For many years, she led the Limnological Station of the Lower Rhine (Limnologische Station Niederrhein) based in the city of Krefeld. Focusing on studies of the Lower Rhine, the Limnological Station was associated with various institutions that became part of the Max Planck Society. The approach to constructed wetlands that Seidel originated is variously referred to as the Seidel system, the Krefeld system, and the Max Planck Institute process (MPIP). Her work is the earliest example of vertical flow constructed wetlands, now used widely in Europe and elsewhere. Seidel was also the first to propose horizontal sub-surface flow systems, an area of research that was further explored by her student Reinhold Kickuth. She has been called the "Mother of constructed wetlands". Käthe Seidel was born in 1907 in Frankenstein, Saxony, Germany (now part of the town of Oederan) where she attended school. She trained as a gardener at the agricultural college in Halle, Germany, the Landwirtschaftlichen Hochschule, qualifying at the master's level in 1934. Next, she trained as a horticultural teacher at a college of teacher education in Leipzig, becoming qualified to teach biology, horticulture and plant education. In 1939 she began studying at the University of Greifswald, taking classes in art history and natural sciences. Her studies there were interrupted by World War II, but she had already written extensively, publishing 22 works between 1922 and 1945. In 1947, Seidel continued her studies at Kiel. At the age of 47, on 26 February 1951, Seidel received her doctorate for the dissertation Die Flechtbinse, a study of the plant Scirpus lacustris which lives in riparian zones with slow flowing water.