Article by Annuja Anandaradje(JIPMER)
“Concrete is the second-most consumed on earth after water”. The global cement production in recent years has amounted to 2.8 billion tons, with equivalent quantities of CO2 released into the atmosphere. The energy intensive series of processes, ranging from extracting of the raw material, transportation, and fuel sources for heating kilns, contribute to the fact that 40% of global carbon dioxide emissions are linked to the construction industry.
This adds burden to environmental pollution.
A type of living concrete made from bacteria could one day help to reduce the environmental impact of the construction industry. Wil Srubar at the University of Colorado Boulder and his colleagues have used a type of bacteria, Synechococcus, to create building blocks in a variety of shapes.
The Research team combined the bacteria with gelatin, sand and nutrients in a liquid mixture then placed this in a mould. With heat and sunlight, the bacteria produced calcium carbonate crystals around the sand particles, in a process similar to how seashells form in the ocean. When cooled, the gelatin solidified the mixture into a gel form. The team then dehydrated the gel to toughen it, with the entire process taking several hours. However, its mechanical properties are more similar to mortar, a weaker material usually made with cement and sand and found between the bricks of buildings. It is not yet as strong as regular bricks.
An advantage of using bacteria to create the concrete is that if they are not dehydrated entirely, they continue to grow. One brick can be split to create two bricks with some additional sand and nutrient solution. The team showed that one brick could yield up to eight in total after several divisions.
The process has the potential to make energy intensive concrete production more environment friendly because of its reliance on photosynthesis.
Let’s make “! GREEN HOUSES!”