Estimation of greenhouse gas emissions from a wastewater treatment plant using membrane bioreactor technology.

A comprehensive mathematical model was developed for this study to estimate on-site and off-site GHG emissions from wastewater treatment plants (WWTPs). The model was applied to three different hybrid WWTPs (S-WWTP, J-WWTP, and T-WWTP) including anaerobic, anoxic, and aerobic process, located in Seoul City, South Korea. Overall on-site and off-site GHG emissions from S-WWTP, J-WWTP, and T-WWTP were <TEX>$305,253kgCO_2e/d$</TEX>, <TEX>$282,682kgCO_2e/d$</TEX>, and <TEX>$117,942kgCO_2e/d$</TEX>, respectively. WWTP treating higher amounts of wastewater produced more on-site and off-site GHG emissions. On average, the percentage contribution of on-site and off-site emissions was 3.03% and 96.97%. The highest amount of on-site GHG emissions was generated from anoxic process and the primary on-site GHG was nitrous oxide (<TEX>$N_2O$</TEX>). Off-site GHG emissions related to electricity consumption for unit operation was much higher than that related to production of chemicals for on-site usage. Recovery and reuse of biogas significantly reduced the total GHG emissions from WWTPs. The results obtained from this study can provide basic knowledge to understand the source and amount of GHG emissions from WWTPs and strategies to establish lower GHG emitting WWTPs.

Different environmental and social concerns can arise due to the generation of gaseous emissions during the treatment of urban wastewater. However, there is not an extensive knowledge about which are the main potential odour and greenhouse gas (GHG) emission sources in a wastewater treatment plant (WWTP) and their variability. In this study, a multipoint characterization of the gaseous emissions generated in a full-scale municipal WWTP located in Barcelona was conducted, aiming at identifying the main odour and GHG emission sources. The WWTP under study treats an average inlet flow of 33,000 m3 d−1 using a Ludzack-Ettinger system with Membrane BioReactor (MBR) technology, and it has installed a gas caption and treatment system consisting of a biotrickling filter followed by a conventional biofilter to treat part of the off-gases produced during the wastewater treatment. For this work, gaseous emissions characterization campaigns were conducted to assess the proper performance of the gas treatment unit and to estimate the emission factors referred to odorants and GHGs for the different emission sources and to assess the proper performance of the gas treatment system. Besides, a chemical characterization of the different volatile organic compounds (VOC) present in the gaseous emissions was performed through TD-GC/MS. The main potential odour sources were the reception tank, the barscreens building and the primary settler, where odour concentrations were in the range of 1300 and 2600 ou·m−3. Moreover, GHG emissions were found during the primary treatment and in the MBR units, ranging from 2.21 to 68,217.13 mg CO2eq·m−3. Different VOCs such as aromatic hydrocarbons, alkanes and ketones were found in the gaseous emissions with a high variability among all the emission sources. The results obtained are valuable indicators that can be used to develop odour and GHG mitigation strategies in WWTPs and to estimate the environmental impact of these facilities.

Modeling greenhouse gas emissions from biological wastewater treatment process with experimental verification: A case study of paper mill

Understanding the greenhouse gas emissions from China’s wastewater treatment plants: Based on life cycle assessment coupled with statistical data

Estimation of greenhouse gas emissions from a hybrid wastewater treatment plant

Assessment of greenhouse gas emission from A/O and SBR wastewater treatment plants in Beijing, China

Greenhouse gases (GHGs) emissions have been increasing, recently. One of the greenhouse gas emission resources is the anaerobic wastewater treatment process. The up flow anaerobic sludge bed (UASB) reactor is the anaerobic treatment unit located in a dairy wastewater treatment plant (WWTP) in Turkey. Greenhouse gases (GHGs) emission emits from the anaerobic reactor due to the biogas generation. In this study, the on-site greenhouse gas emissions from the anaerobic reactor with and without biogas recovery were estimated from biogas amount and content using a developed model based on IPCC approach. Then, the off-site GHGs emissions were estimated from electricity consumption and chemical use. The biogas recovery reduced the greenhouse gas emissions. The highest reduction of the on-site GHGs emissions was 97%. Chemical use was the major source of the off-site GHGs emissions in this study. The main emission resource was chemical consumption for a UASB reactor located in a dairy WWTP.

Domestic wastewater management in Greece: Greenhouse gas emissions estimation at country scale

Municipal water and wastewater services have complicated sources of greenhouse gas (GHG) emissions, and quantifying their roles is critical for tackling global environmental challenges. In this study we provide a systematic review of the state‐of‐the‐art on GHG emission characterizations of China's urban water infrastructure with the aim of shedding light on global implications for sustainable development. We started by synthesizing a framework on GHG emissions associated with water and wastewater infrastructure. Then we analyzed the different sources of GHG emissions in drinking water and wastewater treatment systems. In drinking water services, electricity consumption is the largest source of GHG emissions. A particular concern in China is the common use of secondary pumping for high‐rise buildings. Optimized pressure management with an efficient pumping system should be prioritized. In wastewater services, non‐CO2 emissions such as methane (CH4) and nitrous oxide (N2O) emissions are substantial, but vary greatly depending on regional and technological differences. Further research directions may include GHG inventory development for urban water systems at the plant level, quantifications of GHG emissions from sewer systems, emission reduction measures via water reclamation, renewable energy recovery, energy efficiency improvement, cost–benefit analyses, and characterizations of Scope 3 emissions.This article is categorized under: Engineering Water &gt; Sustainable Engineering of Water Science of Water &gt; Water and Environmental Change Engineering Water &gt; Planning Water

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.

Aluminum production is a major energy consumer and source of greenhouse gas (GHG) emissions. The regional transfer of the primary aluminum (PA) industry, which mainly consists of the processes of electrolysis and aluminum ingot casting, is currently an important international trend in aluminum industrial development. However, the changes in GHG emissions from aluminum production for such transfers are unclear. This study has established a life cycle assessment model of aluminum industry based on regional transfers in the context of China, determined the GHG emissions of PA and secondary aluminum (SA) production, examined the GHG emission changes of PA production based on regional industry transfer between the years 2007 and 2017, and explored seven driving factors that affect GHG emissions in the aluminum industry. GHG emissions per unit PA and SA production in China decreased by 18.6% and 6.3%, respectively, but the total GHG emissions from aluminum industry still increased by 2.2 times between the years 2007 and 2017. The driving factor analysis showed that the major positive effects of GHG emissions from China's aluminum industry from 2007 to 2017 included the production scale effect of SA and the energy structure effect. Existing regional transfers (between the years 2007 and 2017) did not deliver significant annual GHG emissions reductions. Currently, Xinjiang, Henan, Shandong, and Inner Mongolia are the main PA production provinces in China, although regional transfers have been implemented. This study provides a basis for the improvement and sustainable development of the aluminum industry, suggests policies for regional aluminum development, and proposes a beneficial layout of the aluminum industry.

A procedure for estimating Greenhouse gas (GHG) emissions from a wastewater reclamation plant in Beijing was developed based on the process chain model. GHG emissions under two typical water reclamation treatment processes, the coagulation-sedimentation-filtration traditional process and advanced biological treatment process, were examined. The total on-site GHG emissions were estimated to be 0.0056 kg/m3 and 0.6765 kg/m3 respectively, while total off-site GHG emissions were estimated to be 0.3699 kg/m3 and 0.4816 kg/m3. The overall GHG emissions were 0.3755 kg/m3 under the type 1 treatment, which is much lower than that under the type 2 of 1.1581 kg/m3. Emissions from both processes were lower than that from the tap water production. Wastewater reclamation and reuse should be promoted as it not only saves the water resources but also can reduce the GHG emissions. Energy consumption was the most significant source of GHG emissions. Biogas recovery should be employed as it can significantly reduce the GHG emissions, especially under the type 2 treatment process. Considering the wastewater treatment and reclamation process as a whole, the type 2 treatment process has advantages in reducing the GHG emissions per unit of pollutant. This paper provides scientific basis for decision making.

Municipal wastewater treatment plants (MWWTPs) are considered significant artificial sources of greenhouse gas (GHG) emissions, in the forms of methane (CH4) and nitrous oxide (N2O), during their normal operations. In this study, we used an emission factor method to determine the spatial and temporal distribution characteristics of GHG emissions from MWWTPs in China during the period 2005–2014; influencing factors and uncertainties were also analyzed. Our results show that total GHG emissions from Chinese MWWTPs increased from 326.54 to 1294.03 Gg CO2‐eq between 2005 and 2014, and that regional distribution was extremely variable. During this decade, the proportion of CH4 in the total GHG emissions decreased from 74.1 to 59.4% while that of N2O increased from 25.9 to 40.6%. The observed increase in N2O was probably due to the enhancement of wastewater discharge standards for nitrogen discharge, resulting in lower waterborne but higher atmospheric levels of nitrogen oxides. Our comparison of GHG emissions from wastewater discharging directly to the aquatic environment with that treated at MWWTPs in 2014 indicate that the latter disposal method resulted in an 18‐fold drop in GHG emissions. Regional economic development level and wastewater treatment capacity were the factors most closely related to GHG emissions from MWWTPs; the per‐capita protein supply was closely related to N2O emissions.

Wastewater treatment plants (WWTPs) are one of the important sources of greenhouse gas (GHG) emission. There is a need for systematical tool that can be used to analyze GHG emission from WWTPs, and to evaluate the associated reduction strategies. In this paper, a systematic analysis methodology, called the greenhouse emission pinch analysis (GEPA), is developed for this purpose. GEPA is graphical in nature, and can be used to analyze the on-site and off-site GHG emissions of the WWTP. Furthermore, three GHG reduction strategies, i.e., increased aeration capacity, external carbon source controller, and reuse of biogas, are evaluated for their environmental load and operational cost reduction using the GEPA. A case study is used to elucidate the proposed method. In this study, the third strategy which reuses biogas from anaerobic digestion shows the largest reduction of GHG emissions.

Rice fields and cultivation activities are sources of greenhouse gas (GHG) emissions. Therefore, quantification of the baseline emissions is necessary to discover and implement the appropriate mitigation options for the transition to low-carbon rice production in order to achieve the Sustainable Development Goals (SDGs) by 2030. This study aimed to track and estimate the baseline GHG emissions and the carbon footprint (C-footprint) from rice cultivation in three farmer communities in Thailand. The SMART GHG mobile application (SGA) was used to calculate the GHG emissions from many cultivation activities and calculate the C-footprint of paddy rice production. The field activity data were collected from 71 farmer households with 134 ha of harvested areas in Muang Chang (MJ) sub-district of Nan province, Suan Taeng (ST) sub-district of Suphan Buri province, and Na Kham (NK) sub-district of Nakorn Phanom province. The results from SGA showed that the total GHG emissions of MJ, ST and NK communities accounted for 7.5, 6.3 and 2.9 tCO2e ha&minus;1, respectively. The mean of total GHG emissions from all communities accounted for 5.6 tCO2e ha&minus;1. During the rice growing period with flooded fields, the emission of CH4 contributed to 83.4% of the total GHG emissions. Whereas, the cultivation activities of fertilization, field preparation, harvest, and residue burning shared small emissions of 5.4, 4.4, 3.8 and 2.0%, respectively. The SGA also reported the C-footprint of paddy yields by 1.77, 1.10 and 1.09 kgCO2e kg yield&minus;1 in MJ, NK and ST, respectively. This study indicated that the SGA can effectively demonstrate and track the GHG emissions and C-footprint, which can be developed into a baseline emission and mitigation for low-carbon rice production. This is a challenge for agriculture and rural community development in Thailand.