The aquatic plants referred to as algae are single-celled, nonflowering organisms, untethered to the ocean floor beneath them. A phenomenon known as bioremediation allows these microorganisms to remove pollutants from their surrounding environment as they move—and a new project from the Bio-Integrated Design Lab at London’s Bartlett School of Architecture puts this natural process to work scrubbing polluted water.
Indus, a modular wall system created by Bartlett doctoral candidate Shneel Malik, is designed to clean water polluted with toxic dyes and heavy metals. The ceramic tiles, which are each inlaid with microalgae and a seaweed-based hydrogel, are assembled into exterior walls, so that contaminated water can enter the system and run off the other end clean and usable. After debuting the tiles at A/D/O in New York earlier this year, a wall made up of the Indus system was unveiled this fall in London’s Brompton Design District as part of curator Jane Withers’s Nature/Nurture program exploring how design is in conversation with our natural environment. The project’s broader, ongoing mission is to address water and soil pollution from textile dyes in India with affordable, l0w-tech infrastructure.
Indus‘s origins trace back to 2016, when Malik traveled to India as part of a project funded by the U.K. government aimed at solving global challenges, such as water pollution. Local, small-scale jewelry makers and textile dyers in India rely on water from natural streams nearby, which are heavily contaminated with cadmium, lead, and arsenic—thanks, in part, to the color dyes used on their fabrics. These toxic metals pollute the groundwater, soil, and air, which poses multigenerational health threats to the community.
“With the support of NGOs such as Pure Earth and CEE in India, who are involved in tackling pollution, we were able to visit multiple sites in Kolkata (bangle-makers) and Panipat (textile dyers) in India,” Malik says. “These site visits made us better understand the site- and context-specific constraints and challenges in wastewater treatment. Neither the artisan workers have any space available for Westernised high-tech water treatment solutions, nor do they have the economic capacity to get additional support. . . . Therefore, we started to design a system—which is both spatially compatible, but more importantly can be constructed and maintained by the artisans themselves.”
The trip made Malik and her collaborators interested in how low-tech, passive solutions—such as algae—could help absorb heavy, toxic metals from wastewater. The system they came up with imbues architectural tiles with algae hydrogel, which cleans water of pollutants and toxins thanks to their natural bioremediation capabilities. The tiles are made from clay because it is a locally available material in India; in fact, the first set of ceramic Indus tiles were fabricated by native artisans in Khurja, India’s ceramic capital.
To use the Indus system, individuals simply pour polluted water into inlets at the top of the modular wall, allowing the water to flow through the veiny, leaf-like channels of the inlaid tiles. The water gets purified and can be recirculated through the wall for further treatment, depending on its initial level of contamination.
“We conducted lab tests to understand the heavy-metal uptake by the microalgae when encapsulated within the biomaterial. This allowed us to identify certain design parameters allowing for optimum water-algae contact,” Malik says. “Further, while we were generating sets of computational simulations, we identified the similarity of the patterns generated to the veins of a leaf, which have evolved to equally distribute water and nutrients across the entire plant. We then amalgamated the two, into the leaf tiles that were exhibited at [London Design Festival]. The venations further add to the modularity of the system, where we can generate different venation systems specific to their heavy-metal contaminant.”
Right now, the hydrogel, which is embedded in each faux leaf mold, can be used for a couple of months. But once it’s saturated with toxic materials, it will need to be replaced. Malik and her team are still researching this aspect of the design, in an effort to “strike a balance between longevity and having a cue of when to replace the system,” she says.
Malik and her team’s next steps are to test a U.K. prototype wall in situ. And in the future, the designer hopes to conduct a pilot project in a textile courtyard in India. Eventually, she hopes to expand the project to include artisan communities who could test the system—and benefit from natural bioremediation.
“As a team of interdisciplinary design researchers, it’s extremely important for us to imagine ways with which we can already begin introducing artificially designed natural processes within today’s context,” Malik says. “Our vision is very much to make Indus available to the local communities in the coming years. In the process, we are hoping to develop a network of NGOs, government organizations, and local artisanal communities that can help us further our research in making possible the adoption of rather high-tech concepts in a low-tech manner, empowering the panchayat communities to leapfrog into the future by inculcating new forms of daily practice for the truly circular economy.”