Flush with success

Chinese companies have devised green, low-cost toilets to be used in dry, underdeveloped areas of Africa

Ning Jing and his team are all specialists in the disposal of nuclear materials, but their current challenge focuses on a far more common waste issue.

The 53-year-old is a co-founder of Beijing Xuri Qingfeng Technology Co, a startup that for five years has been developing an innovative toilet that can be used in areas in Africa with no access to sanitation.

He recalls a visit to Dakar, the capital of Senegal, several years ago that left a deep impression, not least for the toilet used by many locals.

"It was actually just a hole in an open piece of land," Ning says. "Human waste ran out whenever there was rain and went everywhere. Some of the toilets were even close to wells, which poses a severe health risk."

In 2011, Xuri Qingfeng Technology, which is based in Beijing, received $50,000 in funding from the Bill & Melinda Gates Foundation to design an eco-friendly, low-cost sanitation system that can collect and sterilize human waste to be used as natural fertilizer.

Ning explains that volume reduction lies at the core of all waste-disposal, be it nuclear or human. For the latter, however, the biggest challenge is dehydration, as more than 90 percent of excrement is water.

"If you don't count the cost involved, dehydration is no big deal. However, realizing a low-cost, eco-friendly sanitation system (as set out by the Gates Foundation) is not easy," he says.

The foundation's Reinvent the Toilet Challenge, launched in 2011, encourages inventors worldwide to come up with innovative prototypes to be used in adverse conditions. According to the rules, the product must be affordable, working out at no more than 5 cents a day per person.

The toilets, sewers and wastewater treatment facilities used in the developed world require vast amounts of land, energy and water, and are expensive to build, maintain and operate. "The less-expensive alternatives that exist now are often unappealing because they don't kill pathogens that can cause disease, have impractical designs or are smelly," says Li Zifu, an expert in environmental science and waste management at Beijing's University of Science and Technology.

Xuri Qingfeng Technology's sanitation system separates urine and excrement, with the former sent into a purification tube that has thousands of small, ceramic balls, which act as a filter. The prototype also has two containers affixed to the roof where the feces is reduced and sterilized using heat.

"The biggest hurdle in the regions worst hit by poverty is a lack of water or underground sewerage systems," Ning says. "So our sanitation system has to be able to run independently and treat the waste.

"To be eco-friendly, the system needs to run on clean energy, and it also needs to be small and easy to use, otherwise no one will want to use it," he says, adding that his team chose to power its design on solar energy, which is abundant in Africa. "The lack of sanitation is often the cause of epidemics in Africa, such as diarrhea. With high-temperature sterilization (as used in his design), the risk of any disease spreading can be better controlled."

The entire system covers 2 square meters and is designed to handle the waste produced by an average family of eight to 10 people. The two containers run alternatively and need to be emptied once a week. The contents can then be used to fertilize farmland, Ning adds.

In May, Xuri Qingfeng Technology's design was awarded the prize for best innovative idea at China's inaugural National Toilet Innovation Technology Contest. It was among 52 entries submitted from around the world.

Another winner in the contest was Eco-san, a company based in Jiangsu province that has already received orders from Africa for its novel design.

Like Ning's company, the Eco-san sanitation system also runs on solar power and can recycle human waste, although it uses electro-catalytic oxidation to treat it. Eco-san says its system can be used on a larger scale, too.

The system, which costs about $50,000, will be fitted at four primary schools in South Africa this year, serving 300 to 400 students at each, according to Zhou Xiaokang, the company's manager.

"We've visited South Africa several times over the past months to test and improve our design," he says, adding that the schools currently all have poor sanitation conditions. "The areas are short on water, while the traditional flush toilet is not very useful because of a lack of any underground sewer system.

"In addition to a bad odor, the toilets the students use now increase the risk of spreading disease. I hope our design can give the children a better experience as well as inspire new ideas that can change the world."

For Zhang Jian, president of EnviroSystems Engineering and Technology Co, which specializes in wastewater treatment, reinventing the toilet could ultimately prove to be a breakthrough in finding solutions to other pollution problems caused by human activities.

He says human waste contributes more than 90 percent of the nitrogen and phosphorus released into the world's lakes, rivers and oceans. High levels of these chemicals causes algae to grow faster than ecosystems can handle, damaging the water quality, food resources and habitats, and depleting the oxygen aquatic life needs to survive. Some algal blooms also produce toxins and bacteria that can cause a range of illnesses in humans.

"Other wastewater, such as from washing clothes or bathing, is much less harmful and can be described as 'clean'. But nitrogen and phosphorus are like two drops of ink in a pool of water," Zhang explains.

He says the biggest challenge for modern sewage disposal is the amount of polluted water is beyond capacity. "A next-generation toilet that can deal with human waste independently and prevents it from mixing with an underground sewer system will help to expel the 'two inks' from water and reduce the unnecessary side effects," he adds.

Experts also believe the next generation of sanitation will provide a chance to promote and utilize the next generation of urbanization.

Brian Arbogast, director of the Water, Sanitation and Hygiene Program at the Gates Foundation, says, "China has vast potential in this area, as the country boasts unique advantages in technology innovation, research and development, urban planning and construction, and exploration and promotion of new service models.

"We look forward to seeing the award-winning designs put into use and inspire more innovators to help realize a 'toilet revolution'. We also hope China can export its advanced products, technologies and expertise, contributing to improved sanitation for the world's poor."

Contact the writers though yangwangli@chinadaily.com.cn

Fact box

The need for better sanitation in the developing world is urgent, according to the World Health Organization. Its data show that 40 percent of the world's population, 2.5 billion people, lack adequate sanitation facilities, and the consequences can be devastating for human health as well as the environment.

Even in urban areas, where household and communal toilets are more prevalent, more than 2 billion people globally use toilets connected to septic tanks that are not safely emptied or use other systems that discharge raw sewage into open drains or surface waters.

WHO says poor sanitation results in about 700,000 children dying from diarrhea every year worldwide. Chronic diarrhea can hinder child development by impeding the absorption of essential nutrients and reducing the effectiveness of lifesaving vaccines.

( China Daily Africa Weekly 06/24/2016 page30)