TY - CHAP A1 - Adam, Christian A1 - Krüger, Oliver ED - IWA Publishing, T1 - Wastewater as a resource: From rare earth metals to phosphorus N2 - Wastewater contains a diverse array of organic and inorganic compounds and its complex composition strongly depends on the location and the connected dischargers. However, municipal wastewater as a carrier of feces and urine generally contains considerable amounts of the main nutrients nitrogen and phosphorus. The latter is in the focus of the discussions about the recovery potential of wastewater due to the relatively high mass flows of phosphorus in wastewater and the finite nature and decreasing quality of phosphate rock reserves. But due to the presence of the whole periodic table of elements, wastewater might contain further valuable components of interest for recovery including those defined as critical raw materials by the European Commission. Phosphorus and most of the other critical raw materials are fixed in the sewage sludge and after incineration in the sewage sludge ash (SSA). This is accompanied by high concentration factors from wastewater via sludge to ash. However, the mass fractions of the majority of elements in sewage sludge are comparable to those of the earth crust, indicating no relative enrichment. Nevertheless, enrichment factors of 100 or higher are given for phosphorus, copper, zinc, cadmium, silver, tin, lead and the platinum group elements indicating an anthropogenic input. An economic value of sewage sludge was estimated to $460,-/t calculated on the basis of the respective market prices for high purity elements – a theoretical value. A German survey of sewage sludge ashes showed that the mass fractions and the mass flows of most of the elements present in SSA are probably too low for an economic recovery. In most cases the mass flows are rather small compared to the imports and the chemical forms are not suitable for recovery. An exception is phosphorus that is present in high mass fractions up to 13% and that bears a high substitution potential. If the application of P-recovery technologies lead to a further concentration of valuable elements e.g. as by-products in side streams of the process, it would probably make also the recovery of other elements of economic interest. KW - Wastewater KW - Sewage sludge PY - 2018 SN - 978-1-78040-835-4 SN - 978-1-78040-836-1 SN - 978-1-78040-954-2 U6 - https://doi.org/10.2166/9781780408361 SP - 241 EP - 252 PB - IWA Publishing CY - London AN - OPUS4-45679 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -