Engineering and characterization of gymnosperm sapwood toward enabling the design of water filtration devices

Nat Commun. 2021 Mar 25;12(1):1871. doi: 10.1038/s41467-021-22055-w.


Naturally-occurring membranes in the xylem tissue of gymnosperm sapwood enable its use as an abundantly-available material to construct filters, with potential to facilitate access to safe drinking water in resource-constrained settings. However, the material's behavior as a filter is poorly understood, and challenges such as short shelf life have not been addressed. Here, we characterize the operational attributes of xylem filters and show that the material exhibits a highly non-linear dependence of flow resistance on thickness upon drying, and a tendency for self-blocking. We develop guidelines for the design and fabrication of xylem filters, demonstrate gravity-operated filters with shelf life >2 years, and show that the filters can provide >3 log removal of E. coli, MS-2 phage, and rotavirus from synthetic test waters and coliform bacteria from contaminated spring, tap, and ground waters. Through interviews and workshops in India, we use a user-centric approach to design a prototype filtration device with daily- to weekly-replaceable xylem filters, and uncover indicators of social acceptance of xylem as a natural water filter. Our work enhances the understanding of xylem as a filtration material, and opens opportunities for engineering a diverse range of low-cost, biodegradable xylem-based filtration products on a global scale.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bacteriophages / isolation & purification
  • Cedrus / physiology*
  • Drinking Water / analysis
  • Escherichia coli / isolation & purification
  • Filtration / instrumentation
  • Filtration / methods*
  • Ginkgo biloba / physiology*
  • Humans
  • Pinus / physiology*
  • Rotavirus / isolation & purification
  • Water Purification / instrumentation
  • Water Purification / methods*
  • Xylem / physiology


  • Drinking Water