Algae-Based Walls that Purify Water

In 2016, Shneel Malik, a PhD student from Bartlett School of Architecture, travelled from Great Britain all the way to India within a government project focused on addressing global challenges as water pollution. There she noticed that the locals working in jewelry and textile fabric products used water from rivers and brooks highly polluted with cadmium, lead and arsenic, while their own dyes only contributed to aggravating the situation. This would be the starting point for Indus, a system the works with easily assembled tiles that enable the creation of walls that purify the water that flows through them. The interesting fact of this passive purification system is that it is based on low-cost and sustainable hydrogel made of microalgae and seaweed. By using cheap ceramics, its creators have been able to keep costs down.

To purify water, they leveraged a property of seaweed: bioremediation, that is, their ability to reestablish an environment to its natural state by metabolizing or filtering toxic pollutants. Malik decided to use both microalgae and seaweed to create her tiles after conducting lab tests to assess the optimal proportion. These components, however, har far from the only natural element of the design. Together with seaweed, while they were carrying out computer simulations, they discovered that the optimal structure was very similar to that of plant leaves, which have a network specially well suited to distribute water and nutrients. Hence, the final design resembles a prehistoric plant fossil. The veins of these tiles can be fine-tuned to filter different types of heavy metals.  

Another big advantage of the Indus tiles to purify water is their modular concept and the possibility of using them on top of existing structures. Any artisan can assemble them on the spot with little previous training. Once the tiles have been vertically assembled, the users only need to pour polluted water from above. The water runs down and is filtered until it reaches the bottom. If the water is heavily polluted, the water purification process can be repeated several times.          

Self-sustaining rural communities

This innovative technology project, which belongs to the Bio-Integrated Design Lab of Bartlett School is still a work in progress. Currently, these water purifying walls maintain their efficiency for two months, but Malik and her team are working on prolonging their efficiency and implementing an alert system to inform users when the tiles approach the end of their useful life. In the long run, the goal of this water purification project is to provide rural communities in India with the tools to make them self-reliant without the need of heavy investments on infrastructures. Along these lines, renewable energy, such as solar PV panels, are also poised to play an important role.

At I’mnovation-Hub we have already covered many of the promising applications of seaweed as a source of nutrients, as well as in the development of innovative materials or even renewable power generation systems. It looks like its applications are far from running out.

Source: Fast Company