Water hyacinths provide organic manure, cooking gas

Due to the efficient uptake of such nutrients as nitrogen and phosphorus by water hyacinths planted in polluted water to purify it, the plants become very rich in nutrients and very good as organic maure.

It is so used at the Songhai Centre in Port Novo, Benin Republic and other farms. Also, these nutrient-rich water hyacinths with other wastes are kept in a chamber to generate heat.

Even when the water is not re-used, the water hyacinths are planted in trenches where used water on the farm converges to prevent the odour that would have emanated from water used for purposes such as fish farming.

Farms, which have the information, thereby use water hyacinths to prevent offensive odour from waste or recycled water rather than chemicals that could be damaging to the environment.

The water hyacinths are also used as organic manure in the growing of vegetables and other crops, and when no longer needed, together with other wastes, the disposed hyacinth plants are used in generating electricity on the farm.

Digesters can be designed for batch-feeding or for continuous feeding. With batch digesters a full charge of raw material is placed into the digester, which is then sealed off and left to ferment as long as gas is produced. When gas production has ceased, the digester is emptied and refilled with a new batch of raw materials.