Statistics South Africa published research in 2012 showing that just 43.3% of households accessed their water supply from inside their home. Most South African households get their water from other sources on site, from neighbours’ dwellings or from communal taps. The research also shows that access to clean, piped water presents a significant challenge for many other households. In 2012, 3.3% of households got their water from rivers, streams and dams.
Access to clean water is as important as access to water. In ever-growing urban populations, contaminated water significantly increases the spread of water-borne diseases.
Traditional filtration methods can take up large tracts of land, have limited capacity, are expensive to run, and often lack the last-mile infrastructure needed to supply water to the whole population. The need to create low-cost, sustainable water filtration systems remains an imperative for all designers.
Two projects exemplify what is possible in this crucial area.
Devised by John Todd, plant-based water recycling systems break down water contaminants, providing a natural and eco-friendly alternative to traditional water treatment plants.
This technology uses helpful bacteria, fungi, plants, snails, clams and fish to break down and digest pollutants in the water. In essence, the filtration units pulse water through at least three different ecosystems that each process and filter the water in different ways. Each ecosystem is isolated so it is able to interact with the pollutants in the right way to maximise absorption of the nutrients they love. The water is then cycled on to the next community until it is cleaned and ready for human consumption.
John Todd’s plant-based water filtration systems filter water through three different ecosystems to produce clean water fit for human consumption. Image credit: www.inhabitat.com
While these systems are more appropriate for larger scale applications than individual use, other researchers have begun to mimic natural processes to create products that can provide crucial water filtration at a more domestic scale.
Using biomimicry principles — in which design draws inspiration from natural processes — scientists have developed a process of filtering water through the xylem of pine wood. Xylem is the tube-like tissue that transports water from plant roots to leaves. The study showed that the xylem would filter at least 99% of bacteria from the water.
The filtration system is relatively simple. Peel the bark off a pine tree twig and attach the twig to the end of a tube. Seal the tube with epoxy to prevent leakage through any holes. The wood’s pits form a sieve, filtering out bacteria. At optimum pressure, the filter can process four litres of water each day.
Low-cost, small scale water filtration can be possible using pine wood. Image source: www.plosone.org
Are you inspired by what you’ve read in this article? Do you have an idea that can provide clean, drinkable, uncontaminated water for communities? Enter the Better Living Challenge by 31 May and stand a chance to see your product become available on the open market!