Details

Autor(en) / Beteiligte

• Kleemann, Rosanna
• Chenoweth, Jonathan
• Clift, Roland
• Morse, Stephen
• Pearce, Pete
• Saroj, Devendra

Titel

Comparison of phosphorus recovery from incinerated sewage sludge ash (ISSA) and pyrolysed sewage sludge char (PSSC)

Ist Teil von

• Waste management (Elmsford), 2017-02, Vol.60, p.201-210

Ort / Verlag

United States: Elsevier Ltd

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• •Sewage sludge P concentrations increase by a factor of 2.5 in PSSC and 8 in ISSA.•Whitlockite is present in both ISSA and PSSC, but PSSC contains more whitlockite.•% P extraction of ISSA and PSSC plateau at 0.6M and 0.8M H2SO4 acid, respectively.•PSSC achieved the highest% P extractions, due to its high whitlockite content. This research compares and contrasts the physical and chemical characteristics of incinerator sewage sludge ash (ISSA) and pyrolysis sewage sludge char (PSSC) for the purposes of recovering phosphorus as a P-rich fertiliser. Interest in P recovery from PSSC is likely to increase as pyrolysis is becoming viewed as a more economical method of sewage sludge thermal treatment compared to incineration. The P contents of ISSA and PSSC are 7.2–7.5% and 5.6%, respectively. Relative to the sludge, P concentrations are increased about 8-fold in ISSA, compared to roughly 3-fold in PSSC. Both PSSC and ISSA contain whitlockite, an unusual form of calcium phosphate, with PSSC containing more whitlockite than ISSA. Acid leaching experiments indicate that a liquid/solid ratio of 10 with 30min contact time is optimal to release PO4-P into leachate for both ISSA and PSSC. The proportion of P extracted from PSSC is higher due to its higher whitlockite content. Heavy metals are less soluble from PSSC because they are more strongly incorporated in the particles. The results suggest there is potential for the development of a process to recover P from PSSC.