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WO-2026096901-A1 - HYDROGELS FOR PHOSPHATE BINDING AND RELEASE

WO2026096901A1WO 2026096901 A1WO2026096901 A1WO 2026096901A1WO-2026096901-A1

Abstract

Hydrogels are provided formed from a first polymer comprising a plurality of amine moieties and a second polymer comprising a plurality of cyclic acid anhydride moieties. Water filtration systems comprising the hydrogels and methods for removing phosphate from a water source using the hydrogels are also provided.

Inventors

  • EFIMENKO, KIRILL
  • XU, Jiangfeng
  • GENZER, JAN

Assignees

  • NORTH CAROLINA STATE UNIVERSITY

Dates

Publication Date
20260507
Application Date
20251031
Priority Date
20241031

Claims (20)

  1. WHAT IS CLAIMED IS:
  2. 1. A hydrogel formed from:
  3. a first polymer comprising a plurality of amine moieties; and
  4. a second polymer comprising a plurality of cyclic acid anhydride moieties.
  5. 2. The hydrogel of claim 1,
  6. wherein the second polymer is crosslinked by the first polymer.
  7. 3. The hydrogel of claim 1 or claim 2, wherein the first polymer comprises a polyalkylamine.
  8. 4. The hydrogel of any one of claims 1-3, wherein the first polymer comprises polyethyleneimine (PEI).
  9. 5. The hydrogel of any one of claims 1-4, wherein the first polymer comprises branched polyethyleneimine (PEI).
  10. 6. The hydrogel of any one of claims 1-4, wherein the first polymer comprises linear polyethyleneimine (PEI).
  11. 7. The hydrogel of any one of claims 1-6, wherein the second polymer comprises a copolymer of at least one cyclic anhydride and one or more additional monomers.
  12. 8. The hydrogel of claim 7, wherein the copolymer is an alternating copolymer.
  13. 9. The hydrogel of claim 7, wherein the copolymer is a statistical or random copolymer.
  14. 10. The hydrogel of any one of claims 7-9, wherein the at least one cyclic anhydride comprises succinic anhydride.
  15. 11. The hydrogel of any one of claims 7-10, wherein the one or more additional monomers comprise a monomer having one or more alkenyl moieties.
  16. 12. The hydrogel of any one of claims 7-11, wherein the one or more additional monomers comprise a vinyl ether or a vinyl ester.
  17. 13. The hydrogel of any one of claims 7-12, wherein the one or more additional monomers comprise an alkyl vinyl ether. 14- The hydrogel of any one of claims 7-13, wherein the one or more additional monomers comprise methyl vinyl ether.
  18. 15. The hydrogel of any one of claims 7-14, wherein the one or more additional monomers comprise ethyl vinyl ether.
  19. 16. The hydrogel of any one of claims 7-15, wherein the one or more additional monomers comprise vinyl acetate or vinyl propionate.
  20. 17. The hydrogel of any one of claims 7-16, wherein the second polymer comprises a constitutional repeating unit having the structure:

Description

HYDROGELS FOR PHOSPHATE BINDING AND RELEASE CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to United States Provisional Patent Application No. 63/714,516, filed October 31, 2024, the disclosure of which is incorporated herein by reference in its entirety. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT This invention was made with government support under CBET2019435 awarded by the National Science Foundation. The government has certain rights in the invention. BACKGROUND Phosphorus is ubiquitous in vital biological processes, including the physiology of living organisms, plant growth and health, and photosynthesis. Over 95% of mined phosphate rock is used as fertilizers and animal feed supplements to support the food supplies in the increasing global population (see United States Geological Survey, "Mineral commodity summaries 2023" (Reston, VA), pp. 134). Unfortunately, the excessive application of fertilizers has resulted in runoff into waterways, leading to eutrophication and freshwater contamination, posing threats to drinking water sources and aquatic biodiversity (see: D. L. Correll, The Role of Phosphorus in the Eutrophication of Receiving Waters: A Review. J. Environ. Qual 27, 261-266 (1998); and Y. Zhang et al., Cause and effect of N/P ratio decline with eutrophication aggravation in shallow lakes. Sci. Total Environ. 627, 1294-1302 (2018)). Nearly 90% of the world's population faces risks associated with phosphorus-related pollution, where anthropogenic phosphorus inputs exceed basin waste assimilation capacity (see M. M. Mekonnen, A. Y. Hoekstra, Global Anthropogenic Phosphorus Loads to Freshwater and Associated Grey Water Footprints and Water Pollution Levels: A High- Resolution Global Study. Water Resour. Res.54, 345-358 (2018)). A viable economic and environmental solution is to recycle phosphate from P-excessive sources, such as eutrophic water bodies, to P-depleted agricultural fields, thereby reducing greenhouse emissions and lowering energy consumption (see S. R. Golroudbary, M. El Wali, A. Kraslawski, Environmental sustainability of phosphorus recycling from wastewater, manure and solid wastes. Sci. Total Environ. 672, 515-524 (2019)). Over half of the excessive phosphate in the soil eventually ends up in water bodies (see C. Alewell et al., Global phosphorus shortage will be aggravated by soil erosion. Nat. Common. 11, 4546 (2020)). Among various P sources in the water, soluble inorganic phosphate is directly available to capture, while organic phosphorus compound requires decomposition to inorganic phosphate before removal. Soluble inorganic phosphate accounts for >50% of phosphorus in wastewater phosphorus (see K. Venkiteshwaran, P. J. McNamara, B. K. Mayer, Meta-analysis of non-reactive phosphorus in water, wastewater, and sludge, and strategies to convert it for enhanced phosphorus removal and recovery. Sci. Total Environ. 644, 661-674 (2018)). Numerous approaches have been developed to capture inorganic phosphates and meet the quality standards. Chemical precipitation and enhanced biological phosphorus removal (EBPR) are two technologies applied in wastewater treatment plants. Nevertheless, the environmental instability of biological treatment and viable regeneration of phosphate precipitates requires a more environmentally friendly, cost-effective, and robust recycling process (see M. K. Perera, J. D. Englehardt, A. C. Dvorak, Technologies for Recovering Nutrients from Wastewater: A Critical Review. Environ. Eng. Sci. 36, 511-529 (2019)). The current strategies to recycle P are multifaceted and include a broad range of inorganic and organic chemical systems. Specifically, the inorganic sorbents include metal oxide-based materials, i.e., zirconium and lanthanum-based materials, showing high selectivity and capacity towards phosphate (see: Q. He et al., Phosphate removal and recovery by lanthanum-based adsorbents: A review for current advances. Chemosphere 303, 134987 (2022); R. Liu et al., Review of metal (hydr)oxide and other adsorptive materials for phosphate removal from water. J. Environ. Chem. Eng. 6, 5269-5286 (2018); and S. M. Ribet, B. Shindel, R. dos Reis, V. Nandwana, V. P. Dravid, Phosphate Elimination and Recovery Lightweight (PEARL) membrane: A sustainable environmental remediation approach. Proc. Natl. Acad. Sci. U.S.A. 118, e2102583118 (2021)). For these metal-based systems, phosphate adsorption relies on the high binding affinity between sorbent and phosphate, the same as chemical precipitation, relying on the insolubility of metal phosphate salts. However, the desorption of captured phosphate is complex. High affinity and insolubility guarantee high P removal capacity but restrict bonded and precipitated phosphate from being recovered. The release of bonded phosphate on metal oxide typically requires high concentrations (>1 M) of alkaline or acidic conditions at high processing temperatures (see: J. Li