Date: 2024-12-21 Page is: DBtxt003.php txt00005578 | |||||||||
Environmental Degradation | |||||||||
Burgess COMMENTARY | |||||||||
News / World Poop power: Ghana turning human waste into energy Groundbreaking disposal methods, which have leapfrogged over Western technologies, transform human waste into valuable fertilizer, biofuel and biodiesel. Text size:IncreaseDecreaseResetShare via EmailPrint Report an Error Save to Mystar Fredrik Sunesson, founder of Slamson Ghana, poses in front his liquid waste storage container holding 'dewatered' fecal matter at his worksite in Accra, the country’s capital. JESSICA CAMPBELL / FOR THE TORONTO STAR Fredrik Sunesson, founder of Slamson Ghana, poses in front his liquid waste storage container holding 'dewatered' fecal matter at his worksite in Accra, the country’s capital. By: Jessica Campbell Mercydalyne Lokko Special to the Star, Published on Sun Sep 15 2013 ACCRA, GHANA—Standing on the beach, Fredrik Sunesson points to a thick, 100-metre-long brown line in the ocean. “Would you believe it?” he says. “That’s all human poop.” This is “Lavender Hill,” an unexpectedly pastoral name for an area that smells only of feces. For the past 20 years, 150 dump trucks, each full of human waste from Ghana’s capital city, have been unloaded here every day. The sewage goes directly into the ocean. “Sanitation is a challenge,” says Nuumo Blafo III, a spokesman for the Accra Metropolitan Assembly (AMA), the government organization in charge of the city’s waste management. Photos View gallery Trucks carrying fecal waste are seen at the Lavender Hill site. The channel in the foreground leads directly to the ocean.zoom But it might not be for long. Groundbreaking disposal methods, which leapfrog Western technologies, are now allowing human waste to be transformed into fertilizer, biofuel and biodiesel. The techniques have the potential to tackle Ghana’s sanitation issues while increasing food production and fuelling the nation. They could also provide other countries with a new approach to waste treatment, one that is cheaper and easier. Transforming waste The Swedish-born Sunesson is among those leading the way. He moved to Ghana six years ago with World Vision Canada. The global development group employed Sunesson for 15 years, six of which he spent working at its head office in Mississauga. But Sunesson says he just couldn’t ignore the city’s dumping grounds — deemed one of Africa’s most damaged wetlands by UNESCO. A year ago, he started a business creating fertilizer and biofuel out of human waste. “No one has ever done this with fecal sludge. The system simply does not exist anywhere else in the world.” PROF. KARTIK CHANDRAN OF NEW YORK’S COLUMBIA UNIVERSITY The company, Slamson Ghana Ltd., is now turning about 750,000 litres of Accra’s liquid waste a day into thousands of kilograms of fertilizer. In two months, the amount of waste being dumped into the ocean was cut in half, says Sunesson, who has partnered with the AMA. “Maybe in about six months or so, we can shut Lavender Hill down permanently.” The process is surprisingly simple. Trucks collect waste from around Accra — from public toilets, homes, hotels and businesses. Half is unloaded into holding tanks at Sunesson’s site, the rest is dumped into the ocean at Lavender Hill. Sunesson’s containers act as sieves, separating the solid garbage that people flush down toilets from the liquid waste. The liquid waste is sent through a pump containing five litres of polymer for every 9,995 litres of water. The polymer “dewaters” the waste. Like a magnet, it separates the feces from the fluid. The filtered water is recycled back into the ocean, although potential partners are now testing it for fish farming and drinking water conversion. The sludge is composted in drying beds and used as fertilizer on crops. Or it is put into an industrial oven and dried almost completely. “It’s like slow-cooking a chicken,” says Sunesson. The waste breaks into small pellets, which emit less carbon when burned as biofuel. Rival method Sunesson isn’t the only person in Ghana pushing innovative methods to clean up the country’s human waste. In the southern city of Kumasi, Prof. Kartik Chandran of New York’s Columbia University is creating biodiesel and other chemicals from fecal matter. He has found a way to extract methane from sludge and chemically convert it to methanol. Isolating methane from feces is common. “It is the biochemical conversion to methanol that is novel,” says Chandran, who says he has filed patents for the process. “No one has ever done this with fecal sludge. The system simply does not exist anywhere else in the world.” That’s because fecal matter can be as challenging to manipulate as it is to smell. Chemicals are best extracted when the sludge is concentrated. Although Chandran’s waste trucks collect the feces before it enters waterways, the texture of sludge is inconsistent. This delays the methane-to-methanol process. As a result, Chandran says his biodiesel is expensive because methanol conversion, a crucial component to biodiesel synthesis, becomes difficult. Producing Chandran’s biodiesel costs about $1.60 (U.S.) a litre, triple the expense required to create the fuel from other organic sources. But his goal is sanitation — keeping fecal sludge out of the ocean — not power. Limiting public exposure to human waste would reduce fecal-borne diseases such as cholera, says Dzido Tawiah-Yirenya, a fish and water specialist at the University of Ghana. About 40 per cent of Ghana’s reported health problems are linked to the illness, she says. Chandran is looking for someone to back his discovery before his funding from the Bill and Melinda Gates Foundation ends in December. Expansion possibilties Slamson Ghana is also looking for more funding. It currently operates at capacity, which is why the AMA still dumps waste into the ocean. The World Bank recently approved a $155-million grant for better sanitation and water supply in Ghana. Adu-Gyamfi Abunyewa, a World Bank procurement specialist, visited Sunesson’s site to discuss a $5-million allocation to Slamson Ghana. “The World Bank is interested in investing in anything that will resolve the problem here,” says Abunyewa. Sanitation isn’t a selling point for all investors. But with waste showing promise as a resource, throwing it in the ocean may be like flushing money down the toilet. In addition to methane, Chandran’s process recovers nutrients such as phosphorous to use in fertilizers. Sunesson’s fertilizer is a direct compost of human waste. Still, Sunesson’s method concerns some, because pathogens in feces can transfer to fertilizer. Amit Pramanik, program director at the Water Environment Research Foundation and an environmental engineer, says this method is “very viable,” as long as the fertilizer is dried properly. And Sunesson says he can scale down his fertilizer production if he ups his biofuel conversion; he just needs more buyers. Burning biofuel cannot spread pathogens, says Akua Nkrumah, a process engineer with Waste Enterprisers, an organization testing Sunesson’s fuel. Outdated processes Chandran’s approach could allow Ghana and other African countries to “leapfrog” waste-management processes used in the West. Western countries mainly use aerobic approaches to treat waste water, adding expensive chemicals for purification. The process requires a lot of energy and expensive infrastructure. But Chandran’s method is anaerobic; no additional resources are needed to manipulate the sludge. The technology can fit in the basement of a multi-storey building, he says, reducing the need for large treatment plants. Pramanik says 70 per cent of the United States is locked into aerobic infrastructure. “It is difficult to abandon (existing technology) overnight.” But some growing cities have reached building limits, says Chandran. Additional waste treatment plants cannot easily be constructed. “It looks like we are putting this more in developing countries, but ultimately it is going to come back here,” Chandran says over the phone from his office in New York City. Aerobic infrastructure is outdated, agrees Pramanik. Anaerobic treatment will be considered in cities, he says, in addition to towns using septic tanks. In Canada, Scott Thurlow, president of the Canadian Renewable Fuels Association, is similarly bullish on turning waste into fuel. “Biodiesel, or renewable content like methanol, has a place in Canada,” he says, adding it’s just a matter of finding a market. The waste epiphany Chandran first visited Ghana in 2010 for a workshop organized by the Gates Foundation. He recalls feeling ecstatic when he saw the Jamestown waste water treatment plant in Accra, a Western-style facility built in 2002. He didn’t expect to find such modern technology in the country. “It was like giving a child new toys,” says Chandran, who hoped to use the plant. But the toys had no batteries. With little explanation, city officials told Chandran he couldn’t have access to the plant. Today, it sits idle, just steps from Lavender Hill, because of high operating costs. That day, as Chandran peered across the street to the ocean, he stared at the same brown line that motivated Sunesson to start Slamson Ghana. In that moment, he decided to do what all African children do when they can’t access toys from the West. He made his own. Read more about: Africa |