hollywoodtone.blogspot.com Water filter made from sapwood provides amazing low-tech solution
hollywoodtone.blogspot.com Water filter made from sapwood provides amazing low-tech solution
Run out of drinking water during a lakeside camping trip? The simply break off a branch from a pine tree, peel away the bark, and slowly pour lake water through the stick.
That’s the solution according to a research team at MIT. The scientists are of the view that their improvised filter should trap any bacteria, producing fresh, uncontaminated water. It can also produce enough water for one person a day: scientists have discovered that this low-tech filtration system can produce up to four liters of drinking water a day. The researchers say this is because the size of the pores in sapwood -- which contains xylem tissue evolved to transport sap up the length of a tree -- also allows water through while blocking most types of bacteria. Xylem is a porous tissue that conducts sap from a tree's roots to its crown through a system of vessels and pores. Each vessel wall is pockmarked with tiny pores called pit membranes, through which sap can essentially hopscotch, flowing from one vessel to another as it feeds structures along a tree's length. To study sapwood's water-filtering potential, the researchers collected branches of white pine and stripped off the outer bark. Before experimenting with contaminated water, the group used water mixed with red ink particles ranging from 70 to 500 nanometers in size. After all the liquid passed through, the researchers sliced the sapwood in half lengthwise, and observed that much of the red dye was contained within the very top layers of the wood, while the filtrate, or filtered water, was clear. This experiment showed that sapwood is naturally able to filter out particles bigger than about 70 nanometers. Next the team flowed inactivated, E. coli-contaminated water through the wood filter. When they examined the xylem under a fluorescent microscope, they saw that bacteria had accumulated around pit membranes in the first few millimeters of the wood. Counting the bacterial cells in the filtered water, the researchers found that the sapwood was able to filter out more than 99 percent of E. coli from water. The findings might also have an industrial application for sapwood provides a promising, low-cost, and efficient material for water filtration. The researchers have published their novel findings in the journal PLoS ONE, in a paper titled “Water Filtration Using Plant Xylem”.
hollywoodtone.blogspot.com Water filter made from sapwood provides amazing low-tech solution