Water Hyacinth: Hardcore Heavy Metal Fan

Water Hyacinth (Eichhornia crassipes) (Source: Diszhal.info)

In 2014, Dr. Judilynn Solidum from University of the Philippines came out with a paper that showed heavy metal lead contaminants—in rice varieties and different types of fish—were beyond the acceptable limits in Metro Manila.  The parameters used were based on values from the Center for Disease Control. Although determining the definite cause of the lead contamination was not part of the scientific paper, it did indicate that water and soil contamination was present.

Fast forward to 2016, the problem has remained and although constant recommendations were made for environmental clean-up, more contaminants just kept piling up in our environs.

But the continuing saga of our aqua hero, the water hyacinth, is that it has been found to absorb a number of heavy metals such as nickel, copper, cadmium and mercury, including lead.  Scientific jargon calls it phytoremediation.

It can also sop up nutrient pollutants such as phosphorus.  Excess phosphorus from agricultural and industrial run-offs cause dissolved oxygen in the bodies of water to decrease.  And we all know what happens when life doesn’t get oxygen. Too much phosphorus can also cause algal blooms, better known for its resulting red tide.

Phenol from steel, plastic, aluminum, leather, iron and antiseptic manufacturing; as well as hydrocarbons from the processing of crude oil are common contaminants of today’s waterways.  Both are known to be carcinogenic.  Water Hyacinth rhizomes are known to sequester these pollutants.  Even mercury and methylmercury.

This aquatic marvel has a long list of achievements under its superhero skillset.

From China to Korea, from Bogota to India, Iraq to Israel, extensive studies have been accomplished utilizing this lilac-flowered wonder.  Instead of flushing more chemicals into waterways, water hyacinths have become the future of waste management.

But there’s more—

Where do all the nitrogen and hydrocarbon go? That too is another quality of our aqua hero!

Harvesting the water hyacinth—preferably before it dies because it returns the nutrient pollutants back into the water upon death—will yield even more of its benefits.

Its high-nitrogen content with at least 80% in protein form makes it good fertilizer material. As for the hydrocarbon, a study in India reveals another ecological use for this plant: a source of eco-friendly fuel.  Since water hyacinth’s hydrocarbon content is even higher than animal dung—pollution does have a place and time!—this fast producing plant can be turned into biogas. The initial trials show that 10kg of methane can be produced from just 1 kg of Water Hyacinth waste.

Enough said: One man’s villain can indeed be another man’s hero!


Click to access Understanding_Hydrocarbons.pdf



Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s