Denitrifying sulfide removal (DSR) process simultaneously removes nitrate, sulfide and organic matters in the same reactor. This study isolated eight DSR strains and composed a microbial consortium to reveal the stoichiometry and kinetics of autotrophic, heterotrophic and mixotrophic denitrification (DSR). A novel kinetic diagram based on mass and electron balances was proposed to graphically interpret the system kinetics and identify the accessible regime where DSR reactions can be applied. Demonstration of the use of the proposed diagram showed the easy assessment of DSR system performance by the status on the diagram. (C) 2014 Elsevier Ltd. All rights reserved.