Knowledge Agora



Scientific Article details

Title Phosphorus recovery and reuse potential from smouldered sewage sludge ash
ID_Doc 6587
Authors Fournie, T; Rashwan, TL; Switzer, C; Gerhard, JI
Title Phosphorus recovery and reuse potential from smouldered sewage sludge ash
Year 2022
Published
DOI 10.1016/j.wasman.2021.11.001
Abstract Smouldering treatment of sewage sludge - and recapturing phosphorus - provides important steps towards a circular economy. This study reveals that bulking sludge with sand or another organic waste, e.g., woodchips, created a material that was readily converted to ash by self-sustained smouldering. Simultaneous phosphorus and regulated potentially toxic element releases from ash were evaluated using leaching methods from the USEPA Leaching Environmental Assessment Framework (LEAF). Extraction potentials were also determined to evaluate direct recovery as an alternative to land application. Compared to the parent sludge, post-treatment ash from smouldering sludge with sand contained higher quantities of inorganic phosphorus in sorbed and mineral phases, which can provide beneficial slow phosphorus release to plants and avoid early phosphorus washout during land application. Ash also released lower initial and total quantities of potentially toxic elements than virgin sludge. As an alternative to land application, approximately 42% of retained phosphorus can be recovered directly using acidic extraction, and an additional 30% from emissions. In contrast, co-smouldering sludge with woodchips was more suited for direct recovery with 78% of phosphorus potentially recoverable via emissions capture and yield increasing to 99% with acidic extraction of resulting ash. Co-smouldering also produces a single post-treatment ash and can be readily operated continuously, which aligns with current incinerator configurations at wastewater treatment plants and makes adaptation highly feasible. With phosphorus reuse opportunities for land application and direct recovery, smouldering sewage sludge creates an important opportunity for a phosphorus circular economy as part of wastewater treatment sludge management.
Author Keywords Phosphorus; Smouldering; Sewage sludge; Potentially Toxic Elements; Land application; Recovery
Index Keywords Index Keywords
Document Type Other
Open Access Open Access
Source Science Citation Index Expanded (SCI-EXPANDED)
EID WOS:000746706200005
WoS Category Engineering, Environmental; Environmental Sciences
Research Area Engineering; Environmental Sciences & Ecology
PDF
Similar atricles
Scroll