Wastewater treatment process impact on energy savings and greenhouse gas emissions

2014 ◽  
Vol 71 (2) ◽  
pp. 303-308 ◽  
Author(s):  
D. Mamais ◽  
C. Noutsopoulos ◽  
A. Dimopoulou ◽  
A. Stasinakis ◽  
T. D. Lekkas
Keyword(s):  
Wastewater Treatment ◽  
Energy Consumption ◽  
Greenhouse Gas ◽  
Energy Savings ◽  
Wastewater Treatment Plants ◽  
Specific Energy Consumption ◽  
Ghg Emissions ◽  
Wastewater Treatment Process ◽  
Conventional Activated Sludge

The objective of this research was to assess the energy consumption of wastewater treatment plants (WWTPs), to apply a mathematical model to evaluate their carbon footprint, and to propose energy saving strategies that can be implemented to reduce both energy consumption and greenhouse gas (GHG) emissions in Greece. The survey was focused on 10 WWTPs in Greece with a treatment capacity ranging from 10,000 to 4,000,000 population equivalents (PE). Based on the results, annual specific energy consumption ranged from 15 to 86 kWh/PE. The highest energy consumer in all the WWTPs was aeration, accounting for 40–75% of total energy requirements. The annual GHG emissions varied significantly according to the treatment schemes employed and ranged between 61 and 161 kgCO2e/PE. The highest values of CO2 emissions were obtained in extended aeration systems and the lowest in conventional activated sludge systems. Key strategies that the wastewater industry could adopt to mitigate GHG emissions are identified and discussed. A case study is presented to demonstrate potential strategies for energy savings and GHG emission reduction. Given the results, it is postulated that the reduction of dissolved oxygen (DO) set points and sludge retention time can provide significant energy savings and decrease GHG emissions.

scholarly journals Benchmarking of energy consumption in municipal wastewater treatment plants – a survey of over 200 plants in Italy

2018 ◽  
Vol 77 (9) ◽  
pp. 2242-2252 ◽  
Author(s):  
M. Vaccari ◽  
P. Foladori ◽  
S. Nembrini ◽  
F. Vitali
Keyword(s):  
Wastewater Treatment ◽  
Energy Consumption ◽  
Municipal Wastewater ◽  
Energy Savings ◽  
Wastewater Treatment Plants ◽  
Specific Energy Consumption ◽  
Oxygen Demand ◽  
Energy Performance ◽  
High Energy ◽  
Municipal Wastewater Treatment

Abstract One of the largest surveys in Europe about energy consumption in Italian wastewater treatment plants (WWTPs) is presented, based on 241 WWTPs and a total population equivalent (PE) of more than 9,000,000 PE. The study contributes towards standardised resilient data and benchmarking and to identify potentials for energy savings. In the energy benchmark, three indicators were used: specific energy consumption expressed per population equivalents (kWh PE−1 year−1), per cubic meter (kWh/m3), and per unit of chemical oxygen demand (COD) removed (kWh/kgCOD). The indicator kWh/m3, even though widely applied, resulted in a biased benchmark, because highly influenced by stormwater and infiltrations. Plants with combined networks (often used in Europe) showed an apparent better energy performance. Conversely, the indicator kWh PE−1 year−1 resulted in a more meaningful definition of a benchmark. High energy efficiency was associated with: (i) large capacity of the plant, (ii) higher COD concentration in wastewater, (iii) separate sewer systems, (iv) capacity utilisation over 80%, and (v) high organic loads, but without overloading. The 25th percentile was proposed as a benchmark for four size classes: 23 kWh PE−1 y−1 for large plants > 100,000 PE; 42 kWh PE−1 y−1 for capacity 10,000 < PE < 100,000, 48 kWh PE−1 y−1 for capacity 2,000 < PE < 10,000 and 76 kWh PE−1 y−1 for small plants < 2,000 PE.

scholarly journals Energy Benchmarking and Optimization of Wastewater Treatment Plants in Greece

2020 ◽  
Vol 2 (1) ◽  
pp. 36
Author(s):  
Popi Christoforidou ◽  
George Bariamis ◽  
Maria Iosifidou ◽  
Eri Nikolaidou ◽  
Petros Samaras
Keyword(s):  
Wastewater Treatment ◽  
Energy Consumption ◽  
Energy Savings ◽  
Wastewater Treatment Plants ◽  
Specific Energy Consumption ◽  
Water Environment ◽  
Organic Load ◽  
Technical Data ◽  
Environmentally Sustainable ◽  
Crucial Component

Wastewater treatment, as a crucial component of the urban water environment, consists of several energy-consumptive stages, therefore efficiency and energy savings measures are essential to maintain them as environmentally sustainable and economically viable. Operational and technical data from WWTPs in Greece have been collected as well as a sample from 61 facilities with key energy profile components. Energy consumption was assessed by specific key performance indicators (KPIs); specific energy consumption expressed per population equivalent (from 3 to 150 kWh/PE), per cubic meter treated (from 0.2 to 2.0 kWh/m3) and per unit of organic load removed (from 0.03 to 7.13 kWh/CODremoved).

scholarly journals Contribution of prokaryotes and eukaryotes to CO2 emissions in the wastewater treatment process

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9325
Author(s):  
Katarzyna Jaromin-Gleń ◽  
Roman Babko ◽  
Tatiana Kuzmina ◽  
Yaroslav Danko ◽  
Grzegorz Łagód ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Greenhouse Effect ◽  
Wastewater Treatment Plants ◽  
Ghg Emissions ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Wastewater Treatment Process ◽  
Eukaryotic Organisms ◽  
Quantitative Contribution

Reduction of the greenhouse effect is primarily associated with the reduction of greenhouse gas (GHG) emissions. Carbon dioxide (CO2) is one of the gases that increases the greenhouse effect - it is responsible for about half of the greenhouse effect. Significant sources of CO2 are wastewater treatment plants (WWTPs) and waste management, with about 3% contribution to global emissions. CO2 is produced mainly in the aerobic stage of wastewater purification and is a consequence of activated sludge activity. Although the roles of activated sludge components in the purification process have been studied quite well, their quantitative contribution to CO2 emissions is still unknown. The emission of CO2 caused by prokaryotes and eukaryotes over the course of a year (taking into account subsequent seasons) in model sequencing batch reactors (SBR) is presented in this study. In this work, for the first time, we aimed to quantify this contribution of eukaryotic organisms to total CO2 emissions during the WWTP process. It is of the order of several or more ppm. The contribution of CO2 produced by different components of activated sludge in WWTPs can improve estimation of the emissions of GHGs in this area of human activity.

Evaluation of specific energy consumption and GHG emissions for different drying methods (Case study: Pistacia Atlantica)

2020 ◽  
Vol 259 ◽  
pp. 120963 ◽  
Author(s):  
Mohammad Kaveh ◽  
Reza Amiri Chayjan ◽  
Ebrahim Taghinezhad ◽  
Vali Rasooli Sharabiani ◽  
Ali Motevali
Keyword(s):  
Energy Consumption ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Ghg Emissions ◽  
Drying Methods ◽  
Pistacia Atlantica

scholarly journals Estimation of greenhouse gas (GHG) emissions from natural lagoon wastewater treatment plant: Case of Ain Taoujdate-Morocco

2020 ◽  
Vol 150 ◽  
pp. 01012
Author(s):  
Yassine Bahi ◽  
Ahmed Akhssas ◽  
Mohamed Khamar ◽  
Lahcen Bahi ◽  
Hanane Souidi
Keyword(s):  
Wastewater Treatment ◽  
Greenhouse Gas ◽  
Wastewater Treatment Plant ◽  
Wastewater Treatment Plants ◽  
Ghg Emissions ◽  
Treatment Plant ◽  
Empirical Method ◽  
Monthly Basis ◽  
Total Contribution ◽  
Simple Modeling

The process of removing organic components from wastewater as BOD5 through wastewater treatment plants has been proven to be a significant source of greenhouse gas emissions, mainly methane CH4, carbon dioxide CO2 and nitrous oxide N2O. The reduction of these emissions has attracted more interest given their major contribution to global warming. This study was able to identify and estimate the amount of methane and CO2 emissions on a monthly basis by a simple modeling approach and an empirical method (IPCC) for N2O emissions, in the case of Ain-Taoujdate wastewater treatment plant, throughout the years 2013, 2018 and 2019. The results showed that anaerobic ponds were the main source of on-site emissions with 66% of total contribution and 33% for facultative ponds, followed by the energy consumption of the pumping station as off-site GHG emissions.

scholarly journals Environmental and Energy Assessment of Municipal Wastewater Treatment Plants in Italy and Romania: A Comparative Study

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1611 ◽  
Author(s):  
Daniela Fighir (Arsene) ◽  
Carmen Teodosiu ◽  
Silvia Fiore
Keyword(s):  
Energy Efficiency ◽  
Wastewater Treatment ◽  
Greenhouse Gas ◽  
Municipal Wastewater ◽  
Sustainability Assessment ◽  
Wastewater Treatment Plants ◽  
Ghg Emissions ◽  
Energy Performance ◽  
Municipal Wastewater Treatment ◽  
Municipal Wastewater Treatment Plants

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.

Reductions in greenhouse gas (GHG) generation and energy consumption in wastewater treatment plants

2013 ◽  
Vol 67 (5) ◽  
pp. 1159-1164 ◽  
Author(s):  
L. Yerushalmi ◽  
O. Ashrafi ◽  
F. Haghighat
Keyword(s):  
Wastewater Treatment ◽  
Energy Consumption ◽  
Greenhouse Gas ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Anaerobic Digester ◽  
Biological Processes ◽  
Ghg Emission ◽  
Physical Chemical ◽  
Co2 Equivalent

Greenhouse gas (GHG) emission and energy consumption by on-site and off-site sources were estimated in two different wastewater treatment plants that used physical–chemical or biological processes for the removal of contaminants, and an anaerobic digester for sludge treatment. Physical–chemical treatment processes were used in the treatment plant of a locomotive repair factory that processed wastewater at 842 kg chemical oxygen demand per day. Approximately 80% of the total GHG emission was related to fossil fuel consumption for energy production. The emission of GHG was reduced by 14.5% with the recovery of biogas that was generated in the anaerobic digester and its further use as an energy source, replacing fossil fuels. The examined biological treatment system used three alternative process designs for the treatment of effluents from pulp and paper mills that processed wastewater at 2,000 kg biochemical oxygen demand per day. The three designs used aerobic, anaerobic, or hybrid aerobic/anaerobic biological processes for the removal of carbonaceous contaminants, and nitrification/denitrification processes for nitrogen removal. Without the recovery and use of biogas, the aerobic, anaerobic, and hybrid treatment systems generated 3,346, 6,554 and 7,056 kg CO2-equivalent/day, respectively, while the generated GHG was reduced to 3,152, 6,051, and 6,541 kg CO2-equivalent/day with biogas recovery. The recovery and use of biogas was shown to satisfy and exceed the energy needs of the three examined treatment plants. The reduction of operating temperature of the anaerobic digester and anaerobic reactor by 10°C reduced energy demands of the treatment plants by 35.1, 70.6 and 62.9% in the three examined treatment systems, respectively.

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