Summary: | For future generations, securing nutrients and minimising the biochemical flows are significant challenges for humanity. Due to this, it is important to develop new phosphorous recovery methods from alternative sources to secure food production, reach sustainable development and circular economy. Secondary resources, such as sewage sludge, could compensate for the future limited supply of phosphate rocks. This essay, done by two students from KTH Royal Institute of Technology, Stockholm, Sweden, investigates various aspects of using sewage sludge as fertiliser as a substitute to artificial chemical fertilisers from mine phosphate rock. The study was performed during eight weeks in Cape Town, South Africa, where collection of data was done through interviews and literature. The study aimed to identify strength, weaknesses, opportunities and threats (SWOT) with focus on sustainability to recycle and recover phosphorus through faecal sludge. The SWOT-analysis was done by investigate the technology that was required in the management system, the authorisations and regulations that controls and enable the usage, the economic and socio-cultural approach and acceptance towards the usage of faecal sludge in agriculture. The technology that was investigated was decoupled sewage system with various treatment depending on the end-use. It was identified that the technology is existing and usable but wasn’t established on the market in the region in Western Cape, South Africa. The regulation and classification system that is used by the authorities allowed usage with some restrictions but was in the study identified as an opportunity to develop and reconstruct to adapt to the new technology available today. Acceptance and approach towards the usage of faecal sludge as fertilisers differed depending on the crops grown by the cultivator, but was in general positive. Due to the economic situation for agriculture and wine industry in South Africa, this was the most important factor for the users regarding if they would buy the product if it was available on the market. The conclusion of the study was that the recycling of phosphorus through faecal sludge has potential, but to make an impact on the environment both regional and global, big scale recycling with municipal systems is required.
|