LifeStraw and plant water tube water filtration are affordable ways to provide clean drinking water in water-scarce countries. They utilize a portable filter and a tree filter to purify contaminated water, respectively.

What happens if I drink contaminated water?

We drink and use clean water every day. It’s hard to believe we’re a water-scarce country, with taps everywhere and stores selling filtered drinking water. But there are still people around the world who are dying because they don’t have access to clean drinking water. Drinking contaminated water can lead to diarrheal diseases and infectious diseases, especially dehydration from frequent diarrhea, which often kills people. According to UNICEF statistics, approximately 1.3 million children under the age of five die from diarrheal diseases each year, making it the second leading cause of death among infants and young children. To combat this problem, it is important that filters that can purify water are distributed to areas with contaminated water. In this article, we’ll introduce two water purification technologies designed to address water scarcity.

LifeStraw, a portable water purification device

LifeStraw is a portable water purification device developed by Vestergaard Frandsen. Designed to be used anywhere, the straw-like device removes bacteria and parasites from water by sucking it through a straw. Inside the LifeStraw are porous fibers with holes measuring 0.002 µm. Drinking water flows through them, filtering out bacteria, parasites, and other organisms larger than the size of the pores. In fact, tests have shown a filtration rate of more than 99.9999% for 23 types of bacteria and 99.9% for 7 types of parasites. One LifeStraw can filter about 1000 liters of contaminated water.
In 2005, the LifeStraw won several awards, including “Innovation of the Year” from Esquire and “Best Invention of the Year” from Time. In addition to the portable LifeStraw, VF has developed several other models, including a family LifeStraw that can be used by more people. Designed to require no electricity, the LifeStraw Family can filter about 18,000 liters of water using only gravity. That’s enough drinking water to meet U.S. Environmental Protection Agency (EPA) water quality standards for a family of five for three years.
However, critics argue that LifeStraws are not a radical solution to water scarcity. The $3 price tag makes it prohibitively expensive for people without access to aid, and the fact that LifeStraws are filters for bacteria means that they can’t filter out chemicals, heavy metals, and other chemicals present in drinking water.

Plant Xylem Water Purification Technology

Is it possible to filter water through plants that we see all around us? Boutilier et al. (2014) found that the pit structures present in water pipes can filter pathogenic bacteria from water. Plants move the water they need to survive through their xylem. In the tracheid, a type of water tube, pit structures exist to prevent air bubbles from clogging the water tube. These pores are called pit membranes, and in this study, we used them as filters to filter out bacteria in the water.
The coniferous wood filter used in the experiment had a filtration rate of more than 99.9% against E. coli, and a 1 cm² wood filter can filter 4 liters per day. That’s enough for one person to drink in a day. Since the filter only requires the bark of a tree branch to be peeled off, the technology is expected to be utilized in areas of the world where water is scarce. Existing water purification devices like the LifeStraw have to rely on external support. However, this technology does not require external support as it only requires the water tube of the tree.
This technology is not yet commercialized. It requires research on the tree species that exist in water-scarce countries and the development of a device that can actually use the tree filter. Also, the lifespan of the tree filter is still unknown. If these points are overcome, we could see people in water-scarce countries purifying their water through trees in the future.

What is appropriate technology?

Appropriate technology is technology that takes into account the cultural and environmental aspects of the place where it is used. The two water purification examples above showcase technologies that people in water-scarce countries can easily use to get clean drinking water. They are helping to save lives and improve the quality of life for many people.