Mobile phosphorus stratification in sediments by aluminum immobilization

Juan Lin, Qin Sun, Shiming Ding, Dan Wang, Yan Wang, Musong Chen, Lei Shi, Xianfang Fan, Daniel C.W. Tsang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

54 Citations (Scopus)


In this study, the effects of aluminum sulfate (ALS) on P immobilization were investigated via a 60-day microcosm experiment using sampled sediment cores. The high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) techniques were first employed to establish the profiles of soluble reactive P (SRP) and DGT-labile P in aluminum-amended sediments at 2 and 1 mm resolutions, respectively. Both concentrations of two mobile P forms decreased with increasing ALS dosages. The static layers with extremely low P concentrations (≤0.060 mg L−1for SRP and ≤0.024 mg L−1for DGT-labile P) were observed in the upper 6–16 mm sediment layers at 6–15 ALS/Pmobiletreatments (mobile P is the sum of NH4Cl-P, BD-P, and NaOH-nrP; mol mol−1). The static layer was followed by an active layer in which the upward release potential (RAL) decreased from 33.4 to 21.9 for SRP and from 92.2 to 51.0 for DGT-labile P, respectively. As the formation of the static layer is a key to sustaining P immobilization in sediments, the minimal dosage of 9 ALS/Pmobileis required for ALS capping. Modeling with DGT Induced Fluxes in Sediments (DIFS) showed a greater increase in adsorption rate constant (k1, maximum 7.2-fold) compared to adsorption rate constant (k1, maximum 2.2-fold), demonstrating that the release of P from sediment solids became increasingly difficult after ALS amendment.
Original languageEnglish
Pages (from-to)644-651
Number of pages8
Publication statusPublished - 1 Jan 2017


  • Aluminum sulfate
  • High resolution
  • Immobilization
  • Phosphorus
  • Sediment

ASJC Scopus subject areas

  • Environmental Chemistry
  • General Chemistry


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