376 Organic waste recycling: technology and management
for certain plants but water lettuce seems to be the most common host, followed
by water hyacinth then Azolla and duckweeds.
An effective way to prevent breeding of mosquito in the pond is to stock fish
that feed on mosquito larvae. Successful control was reported by culturing fish
S. Mossambicus in water spinach ponds and Gambusia affinis in water hyacinth
ponds (Edwards 1980; Wolverton et al. 1975).
Biological accumulation in aquatic weeds will occur when wastewater
containing pesticides and heavy metals are treated, thus reducing their potential
as food and as for agricultural purposes. Wastewaters containing toxic materials
should be pretreated to remove these specific contaminants or other alternatives
for treatment and recovery has to be considered.
7.9 References
Bagnall, L.O., Furman, T.D.S., Hentges, J.F., Nolan, W.J. and Shirley, R.L. (1974) "Feed
and Fiber from Effluent-Grown Water Hyacinth". Environmental Protection
Technology Series: EPA-660/2-74-041, Washington, D.C.
Bagnall, L.O. (1979) "Resource recovery from wastewater aquaculture". In Aquaculture
Systems for Wastewater Treatment - Seminar Proceedings and Engineering
Assessment, Report No. EPA 430/9-80-006, pp. 421-439, US Environmental
Protection Agency, Washington, D.C.
Boyd, C.E. (1970) "Amino acid, protein, and caloric content of vascular macrophytes".
Ecology, 51 , 902-906.
Boyd, C.E. (1974) "Utilization of aquatic plants". In Aquatic Vegetation and Its Use and
Control. (Ed. D.S. Mitchell), pp. 107-115, UNESCO, Paris.
Cooper, A. (1976) Nutrient Film Technique of Growing Crops, Grower Books, London.
Cornwell, D.A., Zoltek, J., Jr., Patrinely, C.D., Furman, T.D.S. and Kim, J.I. (1977)
"Nutrient removal by water hyacinths". J. Water Pollut. Control Fed., 49 , 57-65.
Dassanayake, M.D. (1976) "Noxious aquatic vegetation control in Sri Lanka". In Aquatic
Weeds in South East Asia. (Eds. C.K. Varshney and J. Rzoska) pp. 59-61, Dr. W.
Junk B.V., The Hague.
DeBusk, T.A., Williams, L.D. and Ryther, J.H. (1977) "Growth and yields of the
freshwater weeds Eichhornia crassipes (water hyacinth), Lemna minor (duckweed),
and Hydrilla verticillata". In Cultivation of Macroscopic Marine Algae and
Freshwater Aquatic Weeds. (Ed. J.H. Ryther) pp. 275-295, Contract No. E (11-1)-
- US Department of Energy, Washington, D.C.
Dinges, R. (1979) "Development of water hyacinth wastewater treatment systems in
Texas". In Agriculture Systems for Wastewater Treatment - Seminar Proceedings
and Engineering Assessment, Report No. EPA 430/9-80-006, pp. 193-226, US
Environmental Protection Agency, Washington, D.C.
Edwards, P. (1980) "Food Potential of Aquatic Macrophytes". ICLARM Studies and
Reviews No. 5, International Center for Living Aquatic Resources Management,
Manila.