How many types of carbon sources are used on sewage?

At present, many sewage treatment plants use biochemical denitrification to deal with total nitrogen, the carbon source is a key link in the operation of denitrification, whether the total nitrogen can safely meet the standards. Denitrification denitrification can be used in more types of carbon sources, such as methanol, acetic acid, sodium acetate, composite carbon sources, etc., which carbon source in the actual use of acetic acid as a carbon source.