Agricultural waste management pellets. Polymer gel pellets containing nitrifying bacteria that are used to remove ammonia from swine wastewater. The clean-up and disposal of manure from wastewater produced by swine-production is a huge environmental problem. These pellets use large populations of bacteria to break the ammonia down into nitrite, then nitrate, a process known as nitrification. Then the nitrate is converted to nitrogen (denitrification), an odourless gas that is the main component of air. Photographed at the Coastal Plains Soil Water and Plant Research Center in Florence, South Carolina, USA.