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AbstractThe 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 pointsIntegration 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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Immobilized phosphate‐binding protein can effectively discriminate against arsenate during phosphate adsorption and recovery
Abstract There is a strong impetus to establish a circular phosphorus economy by securing internally renewable phosphate (Pi) resources for use as agricultural fertilizers. Reversible Piadsorption technologies such as ion exchange can remove and recover Pifrom water/wastewater for reuse. However, existing reversible adsorbents cannot effectively discriminate against arsenate (As(V)) due to the similarity between As(V) and Pichemical structure. If As(V) is co‐recovered with Pi, the value of the recovered products for agricultural reuse is low. The objective of this study was to construct an immobilized phosphate‐binding protein (PBP)‐based Piremoval and recovery system and analyze its selectivity for Piadsorption in the presence of As(V). A range of conditions was tested, including independent, sequential, and simultaneous exposure of the two oxyanions to immobilized PBP (PBP resin). The purity of the recovered Piproduct was assessed after inducing controlled desorption of the adsorbed oxyanions at high pH (pH 12.5). Piconstituted more than 97% of the adsorbed oxyanions in the recovered product, even when As(V) was initially present at twofold higher concentrations than Pi. Therefore, PBP resin has potential to selectively remove Pi, as well as release high‐purity Pifree of As(V) contamination suitable for subsequent agricultural reuse. Practitioner pointsExisting reversible phosphate (Pi) adsorbents cannot effectively discriminate against arsenate (As(V)) due to the similarity in their chemical structure.Co‐recovery of As(V) with Pican reduce the recovered product's reuse as a fertilizer.An immobilized phosphate‐binding protein (PBP)‐based system can be highly selective for Pieven in the presence of As(V).Piconstituted more than 97% of the recovered product, even when As(V) was present at 2‐fold higher concentrations than Pi.Immobilized PBP offers advantages over existing Piadsorbents by providing high‐purity Piproducts free of As(V) contamination for reuse.
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- Award ID(s):
- 1554511
- PAR ID:
- 10449238
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Water Environment Research
- Volume:
- 93
- Issue:
- 8
- ISSN:
- 1061-4303
- Format(s):
- Medium: X Size: p. 1173-1178
- Size(s):
- p. 1173-1178
- Sponsoring Org:
- National Science Foundation
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