The Earth’s interior is still a mystery to us. While we have sent missions to probe the outer reaches of our Solar system, the deepest boreholes on Earth go down to only a few kilometres. The only way to learn what’s going on deep inside our planet, in the core and the mantle, is by indirect methods.
Refinery wastewater flowing through sand produced biofilms of pollutant-eating bacteria which inturn removed the harmful compounds from the water