Biochar is a super charcoal made by heating any biomass – for example, corncob, husk or stalk, potato or soy hay, rice or wheat straw – without oxygen. All of the cellulose, lignin and other, non-carbon materials gasify and are burned away. What remains is pure carbon – 40% of the carbon originally contained in the biomass.
You probably don't think much about where the water in your tap comes from, but odds are that it has come through a municipal water treatment plant. There are two main types of treatment plants: drinking water and wastewater. Both serve the purpose of cleaning the water, but in general, the output of wastewater plants are streams or rivers, and the output of drinking water plants are your city's pipe network distribution system.