Issue link: http://psai.uberflip.com/i/848539
W EEKLY EDITION JULY 12, 2017 Dispatch #3 from South Africa …continued Research Reveals New Ways of Extracting Value from Human Waste Developers of the DEWATS identify the following benefits of the system: • No energy input required; • Simple to operate and maintain; • Semi - centralized technology and small footprint; • Complies with effluent discharge standards; • Fails safely; • Can be placed in or near the community; • Minimal equipment with a scrap value to reduce the likelihood of theft; and • Potential to produce biogas and to reuse treated effluent for irrigation. Val orization of Urine Nutrients in Africa (VUNA) The term "valorization" is not one we often hear these days. Basically, it means finding a way to give value to something – and that is one of the important shifts in the international approach to handling and processing waste. Rather than seeing it as something bad to be gotten rid of, the vision is to view waste as something of value to be recovered or monetized. With that in mind, in 2010, eThekwini Municipality Water and Sanitation (EWS), teamed up with the Swiss Federal Institute of Aquatic Science and Technology (Eawag) to develop a new and improved sanitation system that allows for nutrient recovery from urine in order to promote toilet use. The project had three basic objectives: • Promote the use of toi lets by giving urine a value; • Produce a valuable fertilizer; and • Protect the environment by reducing pollution. Before the start of the VUNA Project, the urine from urine diversion toilets in eThekwini Municipality was not collected but was left to inf iltrate into the ground. To provide urine for the research on urine treatment a urine collection system had to first be established. Once this was established, the urine was processed into two types of fertilizer: a solid, phosphorus - rich fertilizer (struv ite) and a concentrated liquid containing all the nutrients. The process of producing struvite is initiated by adding a soluble magnesium source. The precipitation process produces solid struvite (MgNH4 PO4 ·6H2 O) from the urine solution during a chemic al reaction, and nearly all the phosphorus can be precipitated from stored urine. The concentrated liquid is produced via nitrification of the urine in a moving bed biofilm reactor (MBBR) followed by vacuum distillation. CONTINUED ON PAGE 5 P AGE 4