Work

Multi-Method Fractionation of Phosphorus Forms in Dewatered Sludge: Implications for Phosphorus Release and Recovery

Year: 2026

Type: article

Abstract: Determining the distribution of phosphorus forms in dewatered sludge is crucial, as it directly impacts the choice and effectiveness of recovery strategies. Analyses using the Standards, Measurements and Testing (SMT) method, soluble/insoluble fractionation and extracellular polymeric substance (EPS)/EPS-residue fractionation revealed that sludge characteristics strongly influenced phosphorus speciation and content. Inorganic phosphorus (IP) was the dominant form in dewatered sludge, primarily regulated by the levels of Al, Fe, and Ca, while dissolved orthophosphate (ortho-P) constituted only 1% of the total phosphorus (TP). Notably, phosphorus exhibited a distinct distribution pattern between EPS and EPS residues: EPS comprised only 2.09% of TP, 74.19% of which was organic phosphorus (OP), whereas EPS residues contained 93.26% of TP, with a much lower OP proportion (15.04%). These results indicate that most phosphorus in dewatered sludge is retained in insoluble and residue-bound forms. Therefore, pretreatment strategies that promote the conversion of solid-phase phosphorus into dissolved ortho-P are necessary for improving phosphorus recovery from dewatered sludge, supporting waste valorization and more sustainable sludge management.

Source: Sustainability

DOI: 10.3390/su18136434

Authors: Zhigang Liu, Junjie He, Siqi Zhou, Xiaohu Dai

Institution: Tongji University

Language: English

Topic: Phosphorus and nutrient management

Subfield: Waste Management and Disposal

Field: Environmental Science

Domain: Physical Sciences

SDGs: Responsible consumption and production, Clean water and sanitation

Open Access status: gold

Estimated APC paid: $2,896