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'Plastic' from hyacinth: how can the problem of water hyacinth be turned into an advantage?

The plant that takes over freshwater lakes around the world, and harms the flora and fauna in them, can be used as a green raw material to replace plastic

It originates in the Amazon, where its growth is balanced by animals and parasitic insects that feed on it. Photography: Yaffe Keder Levy
It originates in the Amazon, where its growth is balanced by animals and parasitic insects that feed on it. Photography: Yaffe Keder Levy

Anyone who has ever been on the giant wheel at Superland enjoys a view of Rishon LeZion's lake. But today the blue spot in the landscape has been replaced by a green spot, due to the takeover of an invasive and deadly plant known as the water hyacinth. This is not the hyacinth flower that we know from the land. The "water hyacinth" is given as a nickname for the foot thick Ichhornia plant - a beautiful but deadly plant that takes over freshwater lakes all over the world and destroys the life in them.

Quick takeover

Water hyacinth Effectively absorbs substances dissolved in water, includes oxygen, and does not leave nutrients for the animals in its environment. Its reproduction rate is extremely high and the plant doubles every 5 days; This rapid takeover pushes out the rest of the water plants, the fish and the birds and leaves them no living space. It originates in the Amazon, where its growth is balanced by animals and parasitic insects that feed on it. It was never supposed to leave there, but its beauty led to humans bringing it to other places, and since then it has done tremendous damage all over the world. 

In Israel, the damage of the plant remains only ecological, but in countries around the world where freshwater reservoirs serve as a main source of nutrition and a route of movement and trade, the water hyacinth directly harms the lives of the residents and even eliminates the fish population and causes food shortages. For example, in Lake Victoria, which covers the territories of Uganda, Kenya and Tanzania on the African continent, the water hyacinth taking over led to a mortality of 30 percent of the fish which the residents of the countries rely on as a main source of nutrition. In Indonesia, the plant's takeover of Lake Rawa Penning Almost preventing fishermen from moving in the water and fishing with nets, the fish has dwindled in the meantime.

The blooming of the water hyacinth in the spurland garden in Rishon Lezion. Photography: Yaffe Keder Levy

in Ghana וin Kenya Chemical-free ecological paper is produced from it, which is used in notebooks, covers and paper packaging. Photography: Yaffe Keder Levy

Turn the disadvantage into a solution

The pesky plant has already taken over about 50 large lakes in the world, but thanks to resourcefulness in some countries they have found creative ways to utilize it. in Ghana וin Kenya it produces chemical-free ecological paper that is used in notebooks, covers and paper packaging; and in Cambodia Women weave household products from its stems and fashionable products such as handbags. On top of that, ways have been found in the world to use water hyacinth as biofuel nee, as a fertilizer for plants And even as food for cattle

A particularly surprising use of the dominant plant is in the production of a biodegradable substitute for plastic. Bio-plastic is a vegetable plastic substitute, which to produce it requires a large amount of Cellulose, a substance found in the cell wall of plants. Today, bioplastics are produced mainly from corn starch and sugar cane, and thus hundreds of thousands of dunams of agricultural produce important for nutrition are wasted on the production of material thatSometimes it is not even perishable. 

Water hyacinth has several advantages over corn and sugarcane: Its growth rate is faster than corn And there is no need to allocate expensive agricultural land to it, on the contrary - it is necessary to evacuate it on a regular basis from the water sources it controls.  25 percent of the biological material that makes up the water hyacinth It is cellulose, therefore it is possible to produce the "cellulose gum", the intermediate material from which the bio-plastic, also known as CMC, is produced. With minimal chemical intervention, it is possible to produce a polymer that is not soluble in water and to produce a biodegradable plastic substitute without the release of toxic chemicals into the environment. 

Experiments to produce bioplastics from the water plant have become especially popular in the countries of the Asian continent, where students conduct various experiments with the plant as scientific projects. In an article published in the Journal of Physics of Thailand, a complex experiment was described to create a stronger and fully biodegradable bioplastic that could be used in the food packaging industry. In the study, the water hyacinth powder undergoes a process in combination with caustic soda , sodium chloride and natural plastic material. Drying the solution under gamma rays (radioactive waves used for research and also for radiation of cancer cells) produces a flexible and durable plastic material. The conclusions of several studies What has been done on the subject is that bio-plastic made from the water hyacinth plant can replace food packaging made of plastic.

First lake will remain green?

Attempts have also been made in Israel to solve the problem of the lake in Rishon Lezion and to make positive use of the water hyacinth, but to date no suitable solution has been found. "The plant was not found suitable as food for livestock because it contains a lot of potassium - it is not tasty and in large quantities can even be toxic, and attempts to make fertilizer from it have also failed," says Prof. Avital Gazit, an expert in the ecology of streams and an Israel Prize laureate. "The water hyacinth is one of the plants that grows very quickly and creates green biomass that can be easily harvested, and although it is an excellent plant for water desalination, we found that it is not suitable for use in Shapadan (the Institute for the Treatment and Rehabilitation of Gush Dan Wastewater)."

Although, according to Gazit, today there is a new Israeli method that knows how to produce plastic from organic waste, the amount of water hyacinth that grows in Israel is not enough for this. "In terms of the use of water hyacinth, we are in a problem because even if there is a person who wants to use it for the production of 'plastic', there is not enough of the plant in the small lake of Rishon Lezion to open a factory; A plant needs serious biomass. We do not have such areas in Israel, we are not a country rich in water", he concludes.