Abstract
Municipal wastewater treatment plants (MWWTPs) are essential infrastructures in any urban context, but they may be considered as a potential source of greenhouse gas (GHG) emissions and should be coherent with European Union (EU) policy on energy efficiency. This study presents a sustainability evaluation of four Italian and Romanian MWWTPs in terms of energy efficiency and greenhouse gas emissions using Energy Performance and Carbon Emissions Assessment and Monitoring (ECAM) tool software. The obtained results indicated that biogas recovery improved energy performances, while the largest contributions in terms of GHG emissions were in all cases caused by energy consumption and methane produced during wastewater treatment. The Romanian plants exhibited higher GHG emissions, compared to the Italian plants, mainly because of the different values of national conversion factors for grid electricity (0.41 kg CO2/kWh for Italy and 1.07 kg CO2/kWh for Romania). Two scenarios aimed at enhancing the overall sustainability were hypothesized, based on increasing the serviced population or energy efficiency, achieving significant improvements. A sustainability assessment of MWWTPs should be adopted as a useful tool to help water utilities to introduce low-energy, low-carbon management practices as well as being useful for policy recommendations.
Highlights
Water is considered an important resource in the context of sustainable development, being vital for health, welfare, economic and social development, and conservation of ecosystems [1].Municipal wastewater treatment plants (MWWTPs) lead to the conservation of the aquatic environment by removing from wastewater the pollutants generated by municipalities and industries, andWater 2019, 11, 1611; doi:10.3390/w11081611 www.mdpi.com/journal/waterWater 2019, 11, 1611 minimizing the negative effects on environmental quality and human health [2]
MWWTP management costs may be reduced by ensuring an efficient design and operation of wastewater treatment stages and by generating electricity and heat through biogas valorization
The sustainability of four MWWTPs was investigated using the ECAM tool, permitting us to obtain an overview of the associated energy consumption and the corresponding greenhouse gas (GHG) emissions
Summary
Water is considered an important resource in the context of sustainable development, being vital for health, welfare, economic and social development, and conservation of ecosystems [1].Municipal wastewater treatment plants (MWWTPs) lead to the conservation of the aquatic environment by removing from wastewater the pollutants generated by municipalities and industries, andWater 2019, 11, 1611; doi:10.3390/w11081611 www.mdpi.com/journal/waterWater 2019, 11, 1611 minimizing the negative effects on environmental quality and human health [2]. Municipal wastewater treatment plants (MWWTPs) lead to the conservation of the aquatic environment by removing from wastewater the pollutants generated by municipalities and industries, and. Wastewater utilities can become engines for the circular economy, playing an important role in the water cycle that allows water sanitation and reuse, facilitating energy production and allowing the recovery of various products from wastes. The main identified negative impacts include sludge disposal, electricity and chemical consumption, and direct greenhouse gas (GHG) emissions. The main gases emitted from an MWWTP during the treatment processes are carbon dioxide (CO2 ), methane (CH4 ), and nitrous oxide (N2 O), while carbon dioxide is emitted from the production of energy necessary for the plant operation. By enhancing the energy efficiency of MWWTPs, the carbon dioxide release may be reduced, leading to a decrease in treatment costs and environmental impacts. The production of nitrous oxide is associated with biological nitrogen removal from wastewater as it is an intermediate product of the nitrification and denitrification processes [5]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
