Is it realistic to use water hyacinth for wastewater treatment and nutrient removal in Central Europe?

The use of Eichhornia crassipes (Mart.) Solms (water hyacinth) has been tested in experimental systems in South Moravia (Czech Republic). The results of these experiments showed that the maximum rate of dry matter production and water treatment capacity during the summer period attained values which were comparable to tropical and subtropical zones. However, the vegetative period within natural conditions in South Moravia (and probably in the lowlands of the whole of Central Europe) is approximately half the time of tropical and subtropical zones and is reflected in lower total yields. The main topics of experiments performed in 1991 were: an assessment of the temperature dependence of growth and reproduction ofEichhornia crassipes in conditions prevailing in South Moravia, and the possibility of extending the growing season. The experiments used effluent from the city of Brno municipal waste water treatment plant. A strong temperature limitation was ascertained on the growth of water hyacinth. The intense growth of Eichhornia was investigated after the average daily temperature had reached 18°C. It was possible to prolong the vegetative period of water hyacinth, and treatment of the effluent, by covering experimental basins with a polyethylene shelter.