Wednesday, 16 December 2009

Finding Uses for a Pest - Water Hyacinth

Water Hyacinth - its the scourge of the waterways of the warmer bits of the planet, including Kenya.

As I have posted in a previous blog, while I was in Kenya, we had a day trip to Bungoma - it should have been longer, but the car hire charges didn't allow us to stay - and I was amazed at what these people are doing with this weed.

But our visit was to advise them on the use of water hyacinth as a feed stock for a methane generator. Of course, any organic matter can be used, but some are easier to use than others.

The problem with water hyacinth is that it is a floating weed, so if it is put into an anaerobic digester untreated, it will just float. It is also full of water, being an aquatic plant.

It floats because, on the leaf stem, under the leaf, there is a bulb which is hollow and filled with gas (air?). These have to be burst or removed. Crushing the plant seems like a good idea. Then not only would these little gas bulbs be burst, but some of the water would be expelled as well.

So, to my mind, to make water hyacinth suitable for anaerobic digestion, it needs to be crushed and chopped up.  This can be done manually, but wouldn't it be good if we could devise a machine to do it? Or better still, to reduce costs, use or adapt an existing machine to do the job!

This has been on my mind since my visit to Bungoma, where I was shown a press to make briquettes for cooking. They now have three presses and I started imagining putting two of them together and adding some sort of press across the two of them which would crush the plants, bursting the bulbs and squeezing out excess water. Hopefully, I will soon be able to put ideas to paper.

While I was cogitating on the weed problem, I was contacted by someone in the USA who pointed me to a YouTube video. This showed how to prepare water hyacinth for human consumption. Apparently, it is very nutritious, and as there is an abundance in countries where there are food shortages (e.g. Kenya), I am now wondering if there is a way to use the plant as a regular food source. After all, there is a lake full of the stuff in SW Kenya - and I am sure it exists in other lakes and slow-running water as well.

Water hyacinth apparently makes a very good fodder for cattle. In Florida, USA, they spend millions on removing and destroying the weed. They also spend millions on cattle feed - well, there's a no-brainer!

If you have first-hand knowledge as to where water hyacinth is prevalent in Kenya, please let me know in the comments. In fact, if you have any experience in the use of water hyacinth for anything, please contact me.


Wyndago said...

Hyacinth for human consumption? Great.

Baba Mzungu said...

We have to be careful. Water hyacinth picks up toxins and heavy metals from the water it lives in. So we have to make sure that any harvested for human consumption is tested to make sure that we don't poison anyone