The Indus tile system uses the principle of microalgal bioremediation to clean polluted water. The ability of microalgae to convert complex organic and inorganic waste into less toxic products is the basis of this modular bioreactor – and has clear applications in developing countries, such as the textile industry. The surface was inspired by the veins on a leaf that have evolved to uniformly distribute water. Microalgae are grown on the tile using a novel seaweed-based hydrogel and are secured to the surface’s vein-like channels. Wastewater that flows down the wall is purified as the microalgae isolate heavy metals and degrade compounds from the dyes. The tiles can be used as a façade cladding element or can be tessellated to stand-alone vertical surfaces. The Indus tile system targets small-scale artisanal industries such as those in rural India that lack access to on-site wastewater treatment infrastructure – but with broad applicability in diverse geographies. The innovative building component would enable water regeneration and reuse within manufacturing processes, avoiding dangerous contamination of soil and natural water bodies. The tiles can be made from locally available materials and fabrication methods. Local communities can engage in the manufacturing process as well as in the maintenance operations, contributing to a circular economy.
The LafargeHolcim Awards jury Europe commended the project’s low-tech but high-impact approach. The bio-based technology with an extremely simple production not only makes it widely accessible but also promotes social sustainability through local skills. Based on careful research work, the multilayered and multipurpose character of the project was particularly appreciated: the tile not only purifies the water but can also initiate virtuous economic and social cycles in the communities that adopt this device. In addition, it offers the buildings a beautiful expression that changes over time – showing that a tile can do much more than what we might first think.