The magnitude of the spread of the water hyacinth (Eichhornia crassipes) makes its extermination, either by physical or chemical methods, a costly and painstaking process. The exercise has to be repeated annually for an indefinite period, a burden that poorer nations are hardly equipped to support. The alternative is to find a use for this plant so that its eradication would entail some financial returns. A variety of studies have been carried out in this direction.
The manifold uses to which the plant has been put include principally: (i) a fertilizer, compost and mulch; (ii) fodder; (iii) a raw material for industry; (iv) a protein source and source for carotene and other chemicals; (v) a pollution control agent; and (vi) biomass for biogas production.
This paper represents a review of the past work on eradication and utilization of water hyacinth relevant in water treatment and resource recovery in the field of environmental engineering with special reference to India.