TITLE:
Carbon Footprint Analyses of Wastewater Treatment Systems in Puducherry
AUTHORS:
G. Vijayan, R. Saravanane, T. Sundararajan
KEYWORDS:
Greenhouse Gas (GHG), Intergovernmental Panel on Climate Change (IPCC), Global Warming Potential (GWP), Sequencing Batch Reactor (SBR), Upflow Anaerobic Sludge Blanket (UASB)
JOURNAL NAME:
Computational Water, Energy, and Environmental Engineering,
Vol.6 No.3,
July
27,
2017
ABSTRACT:
Carbon footprint analysis is a method to quantify the life cycle Greenhouse
Gases (GHGs) emissions and identify the measure to reduce climate change
impacts. The Intergovernmental Panel on Climate Change (IPCC) has identified
that the global warming and climate change which is one of the most important
issues in the domain of environment are caused by the excessive emission of
Greenhouse Gases (GHG) mainly constituting Carbon dioxide (CO2),
Methane (CH4) and Nitrous oxide (N2O). The municipal wastewater treatment
plant receives wastewater for treatment and finally discharges the treated
effluent. The emissions of GHG during the treatment of wastewater as well as
during the treatment process of sludge and also for energy generation are
known to be on-site GHG emissions. Off-site GHG emissions are generated
due to transportation and disposal of sludge, off-site energy and chemical
production. In Puducherry, the municipal wastewater is being treated using
oxidation ponds, Upflow Anaerobic Sludge Blanket (UASB) and Sequencing
Batch Reactor (SBR). Wastewater treatment using Sequencing Batch Reactor
(SBR) technology is one of the state-of-the art wastewater management
systems. In this technology equalization, biological treatment and secondary
clarification are performed in a single reactor in a time control sequence. The
emissions of GHG from the Oxidation ponds of 12.5 MLD, UASB reactor of
2.5 MLD and SBR of 17 MLD were assessed based on the IPCC guidelines and
the total emissions of GHG in terms of equivalent of CO2 were compared. The
performance of the SBR is more efficient and the emissions of GHG are less
than the emissions in the UASB as well as in oxidation ponds. The emission of
GHG in SBR is about 60% of the existing treatment systems of oxidation
ponds and UASB thus a reduction of 40% GHG emission could be achieved.