A low tech water filter that was new to me recently:
https://www.youtube.com/watch?v=nSBwJNDDUfc
"...a research article from MIT (link below) that showed the xylem tissue of gymnosperms effectively filtered out all bacteria from contaminated water. In this video I set up a filter using those findings but also, using a never before seen method using grape vines as both a siphon and filter in one. A lab analysis confirmed the presence of e. coli bacteria in the water to be filtered. The water that passed through the grape vines had no detectable e. coli bacteri"
essentially it's using a tree branch as a filter ("the interiors of nonflowering trees such as pine and ginkgo contain sapwood lined with straw-like conduits known as xylem, which draw water up through a tree’s trunk and branches. Xylem conduits are interconnected via thin membranes that act as natural sieves, filtering out bubbles from water and sap.")
no subject
https://www.youtube.com/watch?v=nSBwJNDDUfc
"...a research article from MIT (link below) that showed the xylem tissue of gymnosperms effectively filtered out all bacteria from contaminated water. In this video I set up a filter using those findings but also, using a never before seen method using grape vines as both a siphon and filter in one. A lab analysis confirmed the presence of e. coli bacteria in the water to be filtered. The water that passed through the grape vines had no detectable e. coli bacteri"
https://news.mit.edu/2021/filters-sapwood-purify-water-0325
essentially it's using a tree branch as a filter ("the interiors of nonflowering trees such as pine and ginkgo contain sapwood lined with straw-like conduits known as xylem, which draw water up through a tree’s trunk and branches. Xylem conduits are interconnected via thin membranes that act as natural sieves, filtering out bubbles from water and sap.")