Kisumu youth turn invasive waterweed into a cash cow

By  Elizabeth Ojina

Reporter

Nation Media Group

For years, water hyacinth has been a serious menace for Lake Victoria and its users.

The obnoxious waterweed would choke the lake, hindering several economic activities such as fishing, lake transport and tourism, among others, from taking place in the world’s second-largest freshwater lake.

However, some youths at Dunga Beach in Kisumu County have decided to put into action the proverbial phrase 'When life gives you lemons, make lemonade'.

When the Nation visited them at the beach, Geoffrey Omondi and his colleagues were sorting out waste collected from the nearby restaurants, ready for biogas production.

From some blue plastic buckets, they removed plastic bottles, ropes, glasses and set them aside.

"We normally distribute the plastic buckets to the fishmongers and restaurants around the Dunga area for waste collection. This has helped in keeping the beach clean. Before this initiative they would throw the leftovers in the lake," he says.

Mr Omondi reveals that they usually mix the noxious hyacinth weed with kitchen waste to produce biogas energy for cooking and drying fish, Omena and vegetables.

Available materials 

While most biogas producers use animal waste such as cow dung, chicken and goat droppings, for the Dunga Beach youth they have chosen to use the readily available water hyacinth, fish waste and restaurant leftovers to produce the same gas.

"Considering we are at a fishing area, it is not easy to get cow dung. That's why we settled on the hyacinth and kitchen waste as our raw materials," explains Mr Omondi.

Fish intestine, vegetable waste, water hyacinth are blended using a shredding machine to form a thick paste. This happens inside some six huge biogas digesters caged in metal bars.

Through a funnel, the paste is channeled into the biogas digester for the process of gas formation to start.

Two wheels attached to the biodigester help to mix the paste. They turn the mixture at least three times daily.

"If we leave without turning the mixture several times, then liquids and solids will separate. The process of gas formation starts after three days," explains Mr Omondi.

The bacteria present in the digester is what breaks down the waste to produce biogas, which is a mixture of methane, carbon dioxide, hydrogen sulfide, water vapor, and other gases.

The liquid by-product left after the production of the biogas is called a slurry. The slurry is channeled and stored in a tank.

The liquid by-product from the digester is used as a natural fertiliser to improve crop production. They sell 20 litres of the slurry to farmers at Sh200.

They have fitted a piping system to collect the biogas from the digester. The pipes are connected to cooking appliances.

"We have fitted pipes and burners for the fishmongers to fry their fish. We charge them Sh100 Per day," says Omondi.

Mr Omondi discloses that they started the biogas project way back in 2017 to offer consumers an alternative source of energy other than charcoal.

"Another objective was environmental conservation. We were looking for a clean source of energy which does not harm the environment," he explains. 

Separately they have improvised a kiln for drying fish using a biogas burner.

The process involves cleaning the fish by removing scales, gutting and cutting the fish into pieces.

They apply oil on the racks where the fish will be placed.

Once the fish is placed on the rack they ignite the biogas burner at the base of the kiln.

Using a valve they control the flow of gas and adjust the heat in the kiln.

"Within three to four hours the fish are dried. It is a clean method of preserving Tilapia, Silver Cyprinid popularly known as Omena and Lake Shrimps," said Mr Omondi.

Margaret Ongoe, a fishmonger at Dunga Beach attests that the biogas provides clean energy.

"I have used biogas for years. It is a clean source of energy and cooks faster compared to firewood which is hazardous to human health and destroys the environment," said Ms Ongoe.