Long-term experimental study of the aquatic plant system for polluted river water.

Water purification using artificial wetlands and aquatic macrophyte is attracting attention as a purification technology that can create rich ecosystems while imposing a minimal load on the environment. Because an aquatic plant system requires a large surface area, design specifications and maintenance methods that can obtain the optimum purification effect per unit surface area must be established. Large experimental facilities have been constructed beside a polluted river flowing into Lake Kasumigaura and have been used for a three-year experiment using several kinds of aquatic plants. This report summarizes the characteristics and the design load of the aquatic plant system based on this study and results from other aquatic plant facilities.