Algae and hydrogel coated tiles to clean water
The small-scale manufacturing of textiles and jewellery produces wastewater contaminated with dyes or heavy metals. In countries like India, this water has to be cleaned with limited resources, which means a lot of it ends up in the environment.
“Through our site visits, we realised that neither the artisan workers had any space available for westernised high-tech water treatment solutions, nor do they have the economical capacity to get additional support,” Shneel Malik, one of the researchers, says. “And the governments in these countries are increasingly imposing restrictions on their manufacturing capacity, without being able to provide them with a solution. Therefore, we started to design a system – which is spatially compatible and a system that can be constructed and maintained by them.”
The Indus project, as it is called, is a tile-based, modular bioreactor wall system that cleans water through bioremediation. The project focuses on the rural community of artisans in India, enabling them to regenerate water for reuse within their manufacturing processes.
The tiles are made of clay and are inspired by the architecture of a leaf. Water flows over a series of vein-like channels containing algae prepared in a seaweed-based hydrogel. Microalgae have several mechanisms through which they are able to remove heavy metal contaminants from their environment. While they can absorb heavy metals in low concentrations, when there is severe pollution, the algae start to detoxify their environment by transforming and storing the metals as nanoparticles.
The hydrogel is made from a seaweed derived polymer, which also has the affinity to capture heavy metals. The hydrogel allows the microalgae to continue growing and perform photosynthesis. The materials needed for the hydrogel can be supplied in powdered form, which makes them easy to prepare on site.
In later stages, the hydrogel can be treated to retrieve valuable nanoparticles like cadmium.
The Indus tiles have several advantages. Firstly, they can be made locally using traditional clay making methods. The modularity enables the artisans to construct the wall depending on the site availability as well as the amount of treated water needed. Broken tiles can easily be replaced without the need to dismantle the entire system.
The Indus project has won the A/D/O Mini Water Futures Design Challenge, in the Future Systems and Infrastructure category.
Shneel Malik, Dr. Brenda Parker & Prof. Marcos Cruz,
Bio-Integrated Design Lab, UCL
With support of:
Dr. Laura Stoffels
Photos: Bio-Integrated Design Lab