Reaction sequences in the thermochemical treatment of sewage sludge ashes revealed by X-ray powder diffraction – A contribution to the European project SUSAN

Phosphorus bioavailability of sewage sludge‐based recycled fertilizers

“…Pyrolysis coal was produced from sewage sludge in an oxygen‐free atmosphere at 500°C by Pyreg GmbH (Dörth, Germany). Prior to thermal treatment, calcium chloride (15%, based on the ash content) was added to the sewage sludge in order to increase the plant P availability of the produced coal ( Peplinski et al, ). The production of Mg‐containing sewage sludge ash (Mg‐SSA) from mono‐incineration of sewage sludge was conducted based on the ASH DEC® process (Outotec, Finland).…”

Chemical State of Chromium, Sulfur, and Iron in Sewage Sludge Ash based Phosphorus Fertilizers

“…This was also detected by XRD measurements. 15 In SSA-Na1, small amounts of FeS and Na 2 SO 4 were detected besides CaSO 4 (see for comparison the XANES spectra of reference compounds in Figure 4). Because of the strong white line of the samples, a LCF with the references was very difficult.…”

“…Linear combination fitting indicates Fe 3 (PO 4 ) 2 as a major Fe compound and some Fe 2 O 3 (see Figure 8a). Previous XRD measurements 15 determined Fe 2 O 3 (hematite) as a major iron compound in the SSA. Normally, during sewage sludge incineration, the precipitated iron phosphates from the wastewater treatment plant react with calcium compounds to Fe 2 O 3 and calcium phosphates.…”

Phosphorus in Agriculture: 100 % Zero

“…1). The use of MgCl 2 as a chlorine donator resulted in the formation of two P-phases, chlorapatite and Ca 4 Mg 5 (PO 4 ) 6 (stanfieldite; Peplinski et al 2009). 1 Some of the mineral phases detected by XRD in a raw ash and in the same ash after being thermochemically treated with the chlorine-donor CaCl 2 (a) and MgCl 2 (b) Peplinski et al (2009) different phases is significantly influenced by temperature and chlorine donator used (CaCl 2 or MgCl 2 ).…”