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Title: Enhanced adsorption and slow release of phosphate by dolomite–alginate composite beads as potential fertilizer

The recovery and reuse of phosphorus (P) from wastewater treatment process is a critical and viable target for sustainable P utilization. This study explores a novel approach of integrating ultrafine mineral particles into hydrogel matrixes for enhancing the capacity of phosphate adsorption. Dolomite‐alginate (DA) hydrogel beads were prepared by integrating ball‐milled, ultrafine dolomite powders into calcium cross‐linked alginate hydrogel matrix. The adsorption isotherms followed a Langmuir–Freundlich adsorption model with higher specific adsorption capacity than those reported in literature. The kinetics of phosphate adsorption suggest that the adsorption is diffusion controlled. Investigation of adsorption capacity at differentpHshowed a maximum adsorption capacity in thepHrange of 7–10. Lastly, we demonstrated that theDAbeads are capable of slowly releasing most of the adsorbed phosphate, which is an important criterion for them to be an effective phosphorous fertilizer. This study, usingDAcomposite hydrogel as an example, demonstrates a promising strategy of immobilizing ultrafine mineral adsorbents into biocompatible hydrogel matrix for effective recovery of phosphorous resource from wastewater.

Practitioner points

Integration of dolomite and alginate hydrogel beads is demonstrated using ball milling.

Ball milling process increases the specific adsorption capacity of dolomite on phosphorus.

Adsorption isotherms, kinetics, andpHeffects of the dolomite–alginate beads are investigated.

The dolomite–alginate beads can be used as slow‐release phosphorus fertilizer.

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Award ID(s):
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Water Environment Research
Page Range / eLocation ID:
p. 797-804
Medium: X
Sponsoring Org:
National Science Foundation
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