Utilization of water hyacinth relevant in water treatment and resource recovery with special reference to India

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, (v) 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.