Wednesday,19 September, 2018
Current issue | Issue 1317, (27 October - 2 November 2016)
Wednesday,19 September, 2018
Issue 1317, (27 October - 2 November 2016)

Ahram Weekly

Water hyacinth— a national project

Eichhornia, the water hyacinth, has long plagued Egypt’s waterways, interfering with navigation and absorbing water. But there are solutions, writes Samir Sobhi

Water hyacinth
Water hyacinth
Al-Ahram Weekly

Water hyacinth on the River Nile has always been a source of concern because it absorbs large amounts of water and interferes with navigation.
However, a group of engineering students at Alexandria University has now invented a vessel that collects, drains, compresses and stores water hyacinth for later usage. It is fitted with a moving belt at the front that collects the plants before delivering them to another belt that pushes them through a compressing machine so that they take up only a small space.

The latest official announcement on water hyacinth, dating to this July, said that minister of irrigation Mohamed Abdel-Atti had given urgent directions to assign the cleaning up of the northern section of the Rashed branch of the Nile to the Public Works and Irrigation Company, an affiliate of the Holding Company for Irrigation and Drainage. This sent out a fleet of barges to clear the Nile of the water hyacinth.

But the brilliant engineering students of Alexandria University have come up with something different, and we should think more about such bold ideas and pay greater attention to the wealth of the River and the Mediterranean and Red Seas. There are around 160 islands, according to prominent scientist Suleiman Gouda, stretching over the 1,000km of the Nile and the same number in the Red Sea. While some of these are being used for military purposes, what about the rest? Do we have a clear conception of how these islands could generate wealth for Egypt?
We might perhaps ask the prime minister to put them to use and give the national economy a push, instead of leaving them as sanctuaries for outlaws as some of them are now. At present we don’t even deal with them using the same logic as we do the desert. If anyone comes to develop them, we even sometimes chase that person away instead of helping him.

Eichhornia, the water hyacinth, is a genus of aquatic flowering plant in the family Pontederiaceae. The genus is native to tropical regions in South America and is a seasonal plant that grows and floats on fresh water. It was named by German botanist Karl Sigismund Kunth in honour of the Prussian minister of culture (1840-1848) Johann Friedrich Olbricht Eichhorn.

This waterweed is a serious problem for the Nile Basin countries because it absorbs large amounts of water that could be used for agriculture and obstructs navigation and blocks waterways such as canals and drains. It also consumes the oxygen in the water, threatening marine life such as fish and other organisms. It can harbour snails that carry diseases such as bilharzia.

Although there have been attempts to put the water hyacinth in Egypt to good use such as in manufacturing or for fodder, there have been problems. The plant consumes about four litres of water a day and gathers in canals and drains, making it dangerous to work with.

Research recommends the eradication of water hyacinth since the harm caused by the plant far outweighs the benefits of using it in production. No one has thus far attempted to start a project using the plants, and the focus has been on eliminating it because of its many harmful effects. There has been some success in biologically controlling the plant in Lake Victoria in Africa by using Neochetina weevils, a beetle from South America.

According to Egyptian journalist Lina Alaa, the accumulation of water hyacinth in the Al-Mahmoudiya Canal has caused a severe drop in water levels, threatening the main source of drinking and irrigation water in the Al-Beheira and Alexandria governorates. Water hyacinth absorbs large amounts of water, causing a loss of about three billion cubic metres of Nile water annually. It also impacts fish because they are unable to breed as it blocks the sunlight from reaching deep into the water and absorbs oxygen from the water at night.

Water hyacinth has a very fast growth cycle, especially in the right conditions such as warm temperatures, low levels of sodium, and if accompanied by high levels of fertilisers and industrial waste in canals and drains, making them the ideal environment for this type of plant.

When the annual Nile flood ended in the early 1970s because of the building of the Aswan High Dam in Upper Egypt, water hyacinth proliferated. In the past, the floods naturally flushed away the remnants of the plant, along with waste and other waterweeds every year. Today, the absence of silt in the River Nile has enabled light to penetrate the water at greater depths, and this has helped all manner of weeds to multiply, especially water hyacinth.

Origins: Egypt’s 19th-century ruler Mohamed Ali is sometimes said to have introduced water hyacinth into Egypt as a decorative plant because of its pretty flowers and quick growth. Palace gardeners then threw out excess plants into the Nile, thus afflicting Egypt’s waterways with the weed.
The growth of water hyacinth now obstructs navigation, blocks canals, and prevents irrigation. The plant is also a breeding ground for snails, especially bilharzia snails that stick to the roots, and it is home to reptiles and snakes especially in summer. The plant also reduces oxygen in the water and raises the water’s alkalinity which threatens marine life such as fish.

But perhaps the major problem is the water hyacinth’s voracious appetite for water. The large surface of its leaves and the fact that it floats on the surface causes large losses of Nile water. A single plant can produce up to 48,000 offshoots in just one month, and the presence of so much vegetation in the water causes it to evaporate more quickly, wasting what some studies have claimed may be as much as three billion cubic metres of water, or enough to reclaim 100 feddans of land.

The Ministry of Agriculture spends enormous amounts every year trying to eradicate the weed. However, it can have some benefits, such as in the manufacture of fodder especially for domestic fowl in rural areas. However, the cost of this is high because the yield drops to 10 per cent after the plant is drained of water.
It can also be used as a fertiliser after turning it into compost. The Chinese have succeeded in using it to manufacture lumber and in purifying water from pollutants since it can absorb heavy metals from water and deposit them in its roots. It can also absorb biological pollutants and can spread quickly in polluted areas.

According to Fouad Shaaban, head of the Pesticides Department at the Faculty of Agriculture at Alexandria University, chemical treatment of water hyacinth using herbicides is a problem because though these kill the weed they then find their way to crops and seriously harm them, completely destroying rice crops, for example.

Meanwhile, the plant cannot be effectively combated using natural means such as animals or insects that might eat it, leaving the only effective solution to be mechanically clearing it from waterways, which, though efficient, comes at a high cost.
For Abdullah Mosaad, head of Agricultural Engineering at the Faculty of Engineering at Alexandria University, the mechanical clearance method is the best, and ways have been found to cut the plant’s roots underwater and remove it from waterways. Once this has been done, it can be dried and used in fodder, though this has not been done extensively in Egypt because of a lack of political will, he said.

Solutions: The General Authority for Fish Resources has used two methods to eliminate water hyacinth from Lake Mariout near Alexandria, one mechanical and the other biological.
The first method used crawlers to remove large amounts of weed from the water, and the second used a type of fish called grass carp which can eat its way through huge amounts of water hyacinth and help reduce weeds in fisheries. The carp can live in any area of fresh water, and they have been put in the Al-Mahmoudiya Canal to help eradicate water hyacinth.

But Ali Al-Magdoub, an agriculture professor at Alexandria University, believes water hyacinth is not such a problem and wonders whether there could be ways of taking advantage of it. In the Philippines, they see the plant as a source of wealth, he said, as they do in Bangladesh. “This plant has been sent from God to clean the rivers from dangerous elements including heavy metals that cause cancer. It can purify the water of lead, cobalt, nickel and arsenic,” he said. “And yet we attack the plant and want to destroy it.”

In the Philippines water hyacinth has been used in manufacturing rope, shoes, bags, pots and other products by extracting its fibres. In China, the weed is removed from the water and heavy metals extracted from it for industrial use. In India, water hyacinth is used to generate biogas by removing the plant from the water, partially drying it, and then putting it into tanks to ferment. Large volumes of biogas can then be collected from the fermenting mixture.

add comment

  • follow us on