A new inventory system to estimate greenhouse gas emissions from domestic wastewater treatment plant

Domestic wastewater treatment plant (WWTP) is one of the entities that emit the greenhouse gas (GHG) to the environment because of microbial breakdown of the organics in human waste, and the use of electricity to operate the treatment plant itself. The first GHG inventory in Malaysia has provided a good foundation for the development of a more comprehensive national inventory. However, due to the lack of detail data from actual plant, Malaysia can only produce imprecise estimates for domestic wastewater. Therefore, there is a need to develop a proper database since based on various real plant characteristics and operating conditions, the actual values of GHG emissions from domestic wastewater in Malaysia could be different from other countries. In this study, a new inventory system has been developed to estimate GHG emissions by domestic WWTP, resulting from direct and indirect activities. Referring to the Intergovernmental Panel on Climate Change approach in 2006, the inventory is started for Imhoff tanks, which constitute 12 percent of all domestic treatment plants in Malaysia. The inventory gives preliminary overview on estimation of GHG emissions from onsite domestic treatment plant when treating wastewater for different Population Equivalent (PE) and Biological Oxygen Demand (BOD) loading.