| Title | Efficient recovery of phosphorus in sewage sludge through hydroxylapatite enhancement formation aided by calcium-based additives |
| Authors | Chen, Jingjing Tang, Siqi Yan, Feng Zhang, Zuotai |
| Affiliation | Southern Univ Sci & Technol, Guangdong Prov Key Lab Soil & Groundwater Pollut, Sch Environm Sci & Engn, Shenzhen 518055, Peoples R China Harbin Inst Technol, Sch Environm, Harbin 150091, Peoples R China Peking Univ, Dept Energy & Resources Engn, Coll Engn, Beijing 100871, Peoples R China Southern Univ Sci & Technol, Key Lab Municipal Solid Waste Recycling Technol &, Shenzhen 518055, Peoples R China |
| Keywords | PYROLYSIS TEMPERATURE HEAVY-METALS ASH ISSA EXTRACTION WASTE BIOAVAILABILITY NITROGEN BIOCHAR IRON |
| Issue Date | 15-Mar-2020 |
| Publisher | WATER RESEARCH |
| Abstract | Reclaiming abundant phosphorus from sewage sludge (SS) via pyrolysis for use as a fertilizer has gained increasing attention owing to the rapid depletion of global P reserves. In this study, the enhancement effect of Ca-based additives on sludge P transformation to hydroxylapatite through pyrolysis was systematically investigated. Three Ca-based additives were added in the pyrolysis of SS, and they were found to promote the conversion of sludge P to hydroxylapatite, which is bioavailable to plants. The characterization of the sludge-derived pyrochars indicated that the addition of 10% CaO, 5% Ca(OH)(2), or 10% Ca-3(PO4)(2) facilitated peak hydroxylapatite production. The thermodynamic simulation of the production of hydroxylapatite during pyrolysis showed that these additives increased the enthalpy of the pyrolysis system. Furthermore, the pyrolysis with CaO addition had the lowest enthalpy, thereby suggesting that the addition of CaO during sludge pyrolysis was preferable for recovering sludge P in the form of hydroxylapatite. Moreover, the hydroxylapatite produced with these additives was unstable when the pyrolysis temperature was above 900 degrees C. The pot experiment demonstrated the feasibility using the sludge-derived pyrochars as P fertilizer for plant growth. Therefore, changing the Ca form and/or Ca/P ratio with the addition of Ca-based additives could be an effective strategy for reclaiming P from SS in the form of hydroxylapatite, and this demonstrates a pathway for global P sustainability by recycling P from P-abundant wastes. (C) 2020 Elsevier Ltd. All rights reserved. |
| URI | http://hdl.handle.net/20.500.11897/586271 |
| ISSN | 0043-1354 |
| DOI | 10.1016/j.watres.2019.115450 |
| Indexed | SCI(E) Scopus EI |
| Appears in Collections: | 工学院 |
