The article presents the results pertaining to the effectiveness of nitrogen removal from wastewater using glycerin as an external carbon source. The study was conducted during the process of municipal wastewater treatment in two independent chambers of activated sludge SBR. Glycerin was added to one of the chambers as a source of easily available organic compounds. The study showed that the use of glycerin as an external carbon source to wastewater treatment resulted in a positive influence on the reduction of nitrogen and phosphorus forms. The addition of glycerin contributed to an increase in nitrate removal rates in the denitrification process and to the accelerated removal of ammonium nitrate in the nitrification process; however, no significant relationship was found between the rate of phosphorus compounds removal and the addition of external carbon source in the form of glycerol.