Characterization and preservation techniques of plant xylem as low cost membrane filtration devices

Safe drinking water remains inaccessible for roughly 1.1 billion people in the world.³⁴ As a result, 400 children under the age of 5 die every hour from biological contamination of drinking water.³⁴ Studies have been done to show that plant xylem from the sapwood of coniferous trees is capable of rejecting 99.99% of bacteria from feed solutions.16 Additionally, 4 L/d of water can be filtered with a ~ 1 cm² filter area using a transmembrane pressure of 5 psi, an amount sufficient to meet the drinking needs of one person. However, the main drawback of xylem is that its permeability drops by a factor of 100 or more after being left out to dry for only a few hours. This paper seeks to characterize the performance of the xylem as a filter, determine the minimum length at which the xylem is effective for filtering bacteria, and increase the xylem's ability to rewet (retaining its permeability and rejective capabilities) after drying through the use of polymer coatings. Finally, potential techniques for decreasing the minimum particulate size the xylem can filter are discussed, with the aim of allowing the membrane to filter viruses.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2014

Author dc:creator

• Potash, Benjamin R

Advisor dc:contributor.advisor

• Rohit Karnik.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/92069

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/92069