The Estimation of Domestic Greenhouse Gas Potential from Sewer Pipeline and the Review on Reducing Technologies

The recent accelerating global warming and its consequent disasters call for the immediate greenhouse gas (GHG) reduction. In this regard, the time has arrived to consider applying global warming potential (GWP) value of 20 years’ time-scale rather than 100 years’ one, and the importance of reducing methane emissions has rapidly increased due to its short life span. Sewer pipeline is the source of emitting methane through biological anaerobic conversion. However, it is not recognized as the official source from IPCC due to lack of data and investigation. In Korea, to our knowledge, there has been no study on GHG emissions from sewer pipeline. In the present work, at first, the amount of methane potential from domestic sewer pipeline was calculated considering various parameters. Depending on the organic concentration of sewage and its degradation rate, the potential amount ranged 3.2-13.4 m ton CO2 eq./yr, when GWP100 value was considered. By using GWP20, this amount could reach up to 40.2 m ton CO2 eq./yr, which exceeds the current total domestic methane emissions (27.8 m ton CO2 eq./yr in 2019). The calculation results clearly tells the importance of developing technologies for reducing GHG from sewer pipeline. Later on, the former technologies were largely divided into chemical and physical methods, and reviewed by each. In addition, the limitation of current technologies were mentioned with addressing future works. In Korea, this is the first study regarding on GHG from sewer pipeline, which will be used for estimating the exact amount and establishing carbon neutrality.