Water hyacinth biogas production units at wastewater treatment facility

INVASIVE AQUATIC PLANTS IN FLORIDA and the rest of the world, plants such as water hyacinth, salvinia, azolla, giant reed and hydrilla, are being studied for their potential beneficial uses. For the most problematic of these plants, there are a number of challenges that must be overcome.

Plants are being considered for use as nutrient-rich compost and animal feed. Yet, the plants' high water content (90-95%) and their heavy weight makes them cumbersome and expensive to harvest, transport, dry and prepare in large quantities. Depending on the water quality of the waterbody, hydrilla and water hyacinth may also have a too-high mineral content or traces of toxic elements that can prevent their use in agriculture as soil supplements and feed.

Researchers have considered the use of aquatic weeds to make paper and insulation boards. However, quality paper requires a high fiber content and paper products developed by researchers using water hyacinth are brittle, wrinkle and darken upon drying, and possess poor tear properties.

Water hyacinth is used in some places to make cottage industry goods

The potential for using aquatic plants as a source of biogas has been and is being explored by researchers in Florida, India, and China. The production of methane from decomposing plant material in marshes prompted scientists to investigate aquatic weeds as an alternate fuel source. China has made considerable progress in the field of developing water hyacinth biogas equipment. Yet, the process requires a constant supply of water hyacinth plants. Once a waterbody is cleared of the invasive species, the equipment would need to be shifted to a new site.

And in Thailand, Africa and elsewhere, water hyacinth is dried and used to make furniture and curiosity items. See this article.

However, as of now, very little market exists for harvested aquatic weeds. Although aquatic plants may have less commercial potential than do terrestrial plants, future advances in technology may open promising doors for the economic use of harvested aquatic weeds in Florida and elsewhere.

To learn more about what's been done to utilize harvested aquatic plants, go to the APIRS Database. You will find more than 5,500 citations on the subject.