Water Filtration using Plant Xylem in Northern India

Abstract

Currently, the world is facing scarcity of clean and potable drinking water. We have investigated whether the xylem (a porous conducting tissue) of a plant could be used as a filter to obtain drinking water. Firstly, we chose the appropriate plant for filtration based on our experimentation. Secondly, we used xylem to make a simple water filter and carried out experiments under the pressure head of the pump. Experiments were conducted using xylems of both angiosperms and gymnosperms. Freshly cut xylems of Ashoka tree, Silver Oak, Neem, Mango and Guava trees were screened for filtration. Filtration rate was measured for each plant and they were simultaneously checked for filterability of blue dye water solution. We found that sharp-edged, waxy leaf trees such as Ashoka and Silver Oak can filter water. These belong to the class of gymnosperms. Trees that bloom and give fruit (such as Neem) cannot purify water and remove impurities. The measured flow rate under a pressure of 2.5 psi was about 0.083 ml/s, which corresponds to a filtration rate of 7 litres per day or more and is sufficient for two people.