Low-Cost Water Filtration Inspired by Non-Flowering Trees

Innovation: Academia

MIT

2021

Image: Constantin Popp / Unsplash / CC BY SA - Creative Commons Attribution + ShareAlike

Capture, Absorb, or Filter Organisms

Many living systems must secure organisms for food. But just as one living system must capture its prey to survive, its prey must escape to survive. This results in capture and avoidance strategies that include trickery, speed, poisons, constructed traps, and more. For example, a carnivorous plant called the pitcher plant has leaves formed into a tube that collect water. Long, slippery hairs within the tube face downward. When insects enter the tube seeking nectar, they lose their footing and slide inside, unable to climb out and escape being eaten and digested by the plant.

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Detoxification/Purification of Air/Water/Waste

Ecosystems must be effective at cleaning air, water, and waste because so much of what is in the air, water, and waste is valuable to organisms as resources. In contrast to functions that detoxify or purify at the organism level, this is at a larger scale. To be effective at the ecosystem level, it isn’t the individual efforts of a few organisms that detoxifies and purifies, but the actions of a wide diversity of organisms each contributing to the whole. For example, as water flows through an ecosystem, either aboveground or in the soil, a diversity of organisms take different actions to slow it down, capture excess nutrients from it, and break down harmful chemicals into more benign ones.

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Patents

WO2018013593A1
198.9 KB PDF

Simple filtration system from MIT contains an abundantly available resource, xylem tissue from native trees, that naturally filters pathogens from water.

Benefits

Low cost
Biodegradable
Reduced waste

Applications

Water filtration

UN Sustainable Development Goals Addressed

Goal 3: Good Health & Wellbeing
Goal 6: Clean Water & Sanitation

Bioutilization

Xylem
Gymnosperm sapwood

The Challenge

Water is essential for human survival, and access to clean drinking water is critical for good health. Contaminated drinking water can cause numerous health concerns, including diarrhea and exposure to viruses. Wastewater treatments systems can be expensive to build and require specialized parts from around the world, making the systems inaccessible to many countries.

Innovation Details

The water filtration system is made from the branches of native non-flowering trees, such as pine and ginkgo. These branches contain sapwood lined with interconnected conduits and thin tissue that serves as a sieve, known as xylem. Plants transport water from their roots to the leaves through the xylem. As the water travels through the xylem, pathogens and bacteria are removed. The natural filter, which is made from peeled cross-sections of sapwood branches, is able to produce purified water at a rate of 1 liter per hour. It can also remove 99% of E. coli and rotavirus, the most common cause of diarrheal disease.

Learn more about the use of low-cost xylem filters in India

Learn more about how xylem filters work

Biological Model

Plants contain a tissue called xylem that consists of many small transport tubes. These tubes help transport water and nutrients from the roots to the leaves.

See Related Strategy

pink microscopic image of plant cells with against white background

Biological Strategy

How Trees Lift Water With Little Effort

Plants

The structure of the cells in xylem passively moves water from roots to leaves through a system of chambers and valves, and filters out pathogens.

References

Journal article

Engineering and characterization of gymnosperm sapwood toward enabling the design of water filtration devices

Nature Communications

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