Contribution of prokaryotes and eukaryotes to CO2emissions in the wastewater treatment process

Reduction of the greenhouse effect is primarily associated with the reduction of greenhouse gas (GHG) emissions. Carbon dioxide (CO 2 ) is one of the gases that increases the greenhouse effect - it is responsible for about half of the greenhouse effect. Significant sources of CO 2 are wastewater treatment plants (WWTPs) and waste management, with about 3% contribution to global emissions. CO 2 is produced mainly in the aerobic stage of wastewater purification and is a consequence of activated sludge activity. Although the roles of activated sludge components in the purification process have been studied quite well, their quantitative contribution to CO 2 emissions is still unknown. The emission of CO 2 caused by prokaryotes and eukaryotes over the course of a year (taking into account subsequent seasons) in model sequencing batch reactors (SBR) is presented in this study. In this work, for the first time, we aimed to quantify this contribution of eukaryotic organisms to total CO 2 emissions during the WWTP process. It is of the order of several or more ppm. The contribution of CO 2 produced by different components of activated sludge in WWTPs can improve estimation of the emissions of GHGs in this area of human activity.