Point source pollution and climate change impact from sequential batch reactor wastewater treatment plant

Since sequential batch reactor (SBR) system is sequentially removes carbon, nitrogen and phosphorous in a single reactor by maintaining anoxic and aerobic stages, it recently has attracted a great deal of interest. This study evaluates the impact of wastewater treatment plant (WWTP) with a SBR system on a creek which is the influent tributary to Aegean Sea. Accordingly, this study demonstrates (1) the treatment efficiency of full-scale WWTP; (2) how WWTP influences creek’s water quality from 2012 to 2015; (3) how creek influences receiving body’s water quality; and (4) the potential climate change impact of a SBR treatment system. The study shows that SBR treatment plant complies with standards set by Turkish Legislations with 4-year average of 62 % SS, 71 %BOD, 62 % COD, 32 % TN and 31 % TP removal but the accumulation of pollutants occurs during low flows when point source is dominant. This is the case in the downstream of treated WWTP discharge point. The potential impact of treatment plant on climate change was calculated in terms of greenhouse gas emissions (GHG). The annual methane emissions from SBR alternated from minimum of 68.71 to maximum 248.99 tCO2e. Total emissions (CH4, N2O and emission due to electricity usage) from a full-scale SBR were calculated as 144.22 tCO2e, 318.34 tCO2e, 474.79 tCO2e and 996.62 tCO2e from 2012 to 2015, respectively.