Water Hyacinth (Eichhornia crassipes) usually floats free in large masses but may be rooted in the mud. The plants may range from a few inches to as much as 90cm (3 feet) in height. They have slender rootstocks with rosettes of leaves and dark, fibrous, branching roots dangling beneath the plant. Flowers may be blue, violet, or white and are usually quite showy.
In many regions Water Hyacinth is regarded as being amongst the worst of aquatic weeds. However, there is a continued theme from some researchers that there is significant benefit to be obtained from seeing the Hyacinth a resource rather than a rogue.
In an abstract from 1985, Ricardo B. Jacquez and Walter H. Zachritz II report on Combining nutrient removal with protein synthesis using a water hyacinth-freshwater prawn polyculture wastewater treatment system. They report overall performance of the polyculture system for the removal of total COD, TSS, total coliforms (MPN), and turbidity (NTU) indicated removals of 58, 98, 99.9, and 94 percent, respectively. Other parameters for the two stage system were monitored including temperature, Ortho-P, biomass, productivity, alkalinity, pH, and specific conductance.
F. Shoeb and H. J. Singh (2000) have published Kinetic Studies of Biogas Evolved from Water Hyacinth. The paper deals with the kinetics of gas produced from Water Hyacinth. The study was done in a batch fed digester. Attempts have been made to reach an optimum condition for the production of maximum amount of gas by the addition of lower volatile fatty acids, cow dung and inoculums etc. The conclusions that were drawn from the study is that biogas plants can be run even on the cold winter nights by using certain additives. After digestion, Water Hyacinth inoculums can be used as good manure for soil fertility. They are free from harmful chemicals – a boon for sustainable agriculture practices.
firstname.lastname@example.org have captured information about Uses for water hyacinth – Las Gaviotas project from August 2002. The information lists two links which are now invalid. Sad, because it would be interesting to see how the information had updated over time. This focus of this research has taken a rather different approach:
Scientific research initiated by Margaret Tagwira for ZERI Foundation demonstrated that dried water hyacinth is the best substrate for farming mushrooms. This program directed by Prof. S. T. Chang, an authority on the matter, confirmed that the water hyacinth is a blessing in disguise. Sociological studies confirmed that nearly all African cultures had mushrooms as a part of their diet. The spent substrate after fungi harvesting is rich in protein from the mycelia of the mushrooms and are excellent feed for earthworms, which convert it all into humus and can be fed to chickens, ducks and pigs.
After only 30 days, the dried substrate from water hyacinth produced a variety of mushrooms. Once harvested, it did not take more than ten days to harvest a second and even a third flush. One hundred kilograms of dried water hyacinth generates more than 100 kilograms of mushrooms. The water hyacinth outperforms traditional substrate materials such as sawdust. In addition, since the substrate of water hyacinth is rich in minerals and nutrients, the oyster and straw mushrooms cultivated ended up enriched with potassium, magnesium, iodine and calcium, along with numerous other components that are critical to a healthy food diet. Much of what was lost in the form of washed away topsoil can be recovered in the mushroom. The water hyacinth can also recover harmful metals such as cadmium and lead and store them in their roots if these metals are found in the rivers or lakes.