Compost from human excreta and organic waste
In many rural areas of South Africa, people still dispose of their human excreta in pit latrines. This poses a great challenge for municipalities as the latrines fill up quickly. It also increases people’s risk of coming into contact with pathogens.
Benjamin Wilde, a native of Texas and a postdoc at the Chair of Sustainable Agroecosystems, is trying to solve this problem together with local partners in the Msunduzi municipality: “We’re working with the local company Duzi Turf, a public utility, and the municipality to produce compost from sewage sludge and urban green waste. This is then used as fertilizer,” Wilde says. He coordinates RUNRES from Zurich.
While the municipality supplies the green waste and the public utility company the sewage sludge, the company is responsible for the composting. This collaboration of public and private actors, however, does more than just empty latrines: the organic fertiliser also enhances soil fertility and thus increases local farmers’ crop yields. The compost is used to fertilize green spaces as well as the fields of a neighboring farmers' cooperative, increasing its agricultural yields. What’s more, the local company creates new jobs by selling the compost.
Similar to South Africa, the Runres project in Bukavu, a city in the eastern Democratic Republic of Congo, is about producing compost from organic waste. To improve the collection of this waste in the city, Runres social scientist Leonhard Spaeth worked with researchers from the International Institute of Tropical Agriculture (IITA) to conduct an education campaign that encouraged residents to better separate household organic waste. “Sorting behavior at household level is essential for getting an efficient and cost-effective process-chain from waste to usable input for the agriculture”, Spaeth explains. This work is not only improving waste management in the city, but also public health. The compost is then sold to local coffee farmers, where it is used as fertilizer.