The Use of HF Constructed Wetlands in the World

Haberl et al. (1998) reviewed the situation concerning the use of constructed wetlands in Austria. They pointed out that due to lack of proper wastewater treatment plants in rural and mountain area CWs had been in discussion as an appropriate option for about 15 years in Austria. Several people promoted CW as on-site plants for these areas but at the same time regulatory authorities did not approve the CW technology. The major objections were the lack of long-term experience, winter operation, hygienic problems and clogging of the substrate. After emotional discussions several experimental CWs were built. One of the most extensively studied experimental plant of all times was CW at Mannersdorf built in 1982 (Fig. 7-1) - it had been monitored for 7 years (e.g., Haberl and Perfler, 1989, 1990). At the same year, HF system in Lainzer Tiergarten was put in operation.

The HF constructed wetlands turned out to be a very appropriate technology providing high stability in its efficiency with low levels of operation and maintenance. Removal of organics and suspended solids was efficient, however, HF CWs often proved insufficient as far as the removal of nutrients was concerned.