Excreta reuse in dry sanitation systems The recovery and use of urine and feces in "dry
sanitation systems", i.e. without sewers or without mixing substantial amounts of water with the excreta, has been practiced by almost all cultures. The reuse was not limited to agricultural production. The
Romans, for example, were aware of the
bleaching attribute of the
ammonia within urine and used it to whiten clothing. The value of "
night soil" as a fertilizer was recognized with well-developed systems in place to enable the collection of excreta from cities and its transportation to fields. The Chinese were aware of the benefits of using excreta in crop production more than 2500 years ago, enabling them to sustain more people at a higher density than any other system of agriculture. In Peru, the Incas had a high regard for excreta as a fertilizer, which was stored, dried and pulverized to be utilized when planting maize. In the Middle Ages, the use of excreta and
greywater in agricultural production was the norm. European cities were rapidly urbanizing and sanitation was becoming an increasingly serious problem, whilst at the same time the cities themselves were becoming an increasingly important source of agricultural nutrients. The practice of directly using the nutrients in excreta and wastewater for agriculture therefore continued in Europe into the middle of the 19th century. Farmers, recognizing the value of excreta, were eager to get these fertilizers to increase production and urban sanitation benefited. KNO3 was also responsible for the discovery of
nitric acid in the 17th century. Traditional forms of sanitation and excreta reuse have continued in various parts of the world for centuries and were still common practice at the advent of the Industrial Revolution. Even as the world became increasingly more urbanised, the nutrients in excreta collected from urban sanitation systems without mixing with water were still used in many societies as a resource to maintain soil fertility, despite rising population densities. A publication by Sida called "Ecological sanitation" in 1998 compiled the knowledge generated to date about ecosan in a popular book which was published as a second edition in 2004. French and Spanish. The German government enterprise
GIZ also had a large "ecosan program" from 2001 to 2012. Whilst the term "ecosan" was preferred in the initial stages of this program, it was from 2007 onwards more and more replaced by the broader term "
sustainable sanitation". In fact, the
Sustainable Sanitation Alliance was founded in 2007 in an attempt to broaden the ecosan concept and to bring together various actors under one umbrella. Research into how to make reuse of urine and feces safe in agriculture was carried out by Swedish researchers, for example Hakan Jönsson and his team, whose publication on "Guidelines on the Use of Urine and feces in Crop Production" was a milestone which was later incorporated into the WHO "Guidelines on Safe Reuse of Wastewater, Excreta and Greywater" from 2006. The multiple barrier concept to reuse, which is the key cornerstone of this publication, has led to a clear understanding on how excreta reuse can be done safely.
Workshops and conferences Initially, there were dedicated "ecosan conferences" to present and discuss research on ecosan projects: • A first workshop on ecological sanitation was held in Balingsholm, Sweden in 1997, where all the then established ecosan experts, such as Håkan Jönsson, Peter Morgan (winner of the 2013
Stockholm Water Prize), Ron Sawyer, George Anna Clark and Gunder Edström participated. • Workshop in Mexico in 1999 with the title "Closing the Loop - Ecological sanitation for food security" • Ecosan conference in Bonn, Germany in 2000 • First international ecosan conference in Nanning, China in 2001 • Second ecosan conference in Lübeck Germany in 2003 • Third ecosan conference in Durban, South Africa in 2005 • Ecosan conference in Fortaleza, Brazil called "International Conference on Sustainable Sanitation - Water and Food Security for Latin America" in 2007 Since then the ecosan theme has been integrated into other
WASH conferences, and separate large ecosan conferences have no longer been organised.
Disputes amongst experts During the 1990s, when the term ecosan was something new, discussions were heated and confrontational. Supporters of ecosan claimed the corner on containment, treatment and reuse. The proponents of conventional sanitation systems on the other side defended
pit latrines and waterborne
sewage systems. Ecosan supporters criticized conventional sanitation for contaminating waterways with nutrients and pathogens. Since about 2007, the two opposing sides have slowly found ways of dealing with each other, and the formation of the
Sustainable Sanitation Alliance in that year has further helped to provide a space for all sanitation actors to meet and push into the same direction of sustainable sanitation. ==Examples==