We concluded that a water hyacinth system was effective
in treating wastewater from an intensive duck farm during
the water hyacinth growing season and that, after harvesting,
the water hyacinth was an excellent duck feed.
This study observed the treatment capacity of the CW
with water hyacinth during a 40-d period in autumn. Its
long-term capacity has not yet been studied. In future,
water hyacinth will be replaced by Potamogeton crispus
L. and grassleaf sweetflag rhizome (Rhizoma Acori
Graminei) as the CW aquatic plants during spring and
winter because the growth of water hyacinth stops if the
temperature remains under 0°C for a period of 24 h.
Another point is that the study planted only one type of
wetland plant in the CW. Other studies, however, have
reported that the integration of various plants enhances the
CW treatment capacity (Martin et al., 1996)