Estimation of greenhouse gas emissions from a hybrid wastewater treatment plant

Wastewater treatment plants (WWTPs) using membrane bioreactor (MBR) technology have been considered a significant source of greenhouse gas (GHG) emissions. This study chose a small-scale wastewater treatment plant using MBR technology to estimate its potential for GHG emissions. The total GHG emissions from this wastewater treatment plant ranged from 2,802 to 11,946kg CO2 -eq/month within the 4-year study period, and they were mainly attributable to electricity consumption (79.94%) followed by chemical usages (17.13%) and on-site GHG emissions (2.93%). The on-site GHG emissions varied monthly, but most of them ranged from 80 to 160kg CO2 -eq/month. The aeration tank was an important operating unit for GHG emissions. Off-site GHG emissions mainly came from carbon dioxide (CO2 ) emissions resulting from electricity consumption. The results of this study provide useful information about the potential of GHG emissions from WWTPs using MBR technology and indicate that WWTPs can be sustainably managed. PRACTITIONER POINTS: Wastewater treatment plants have been considered a source of greenhouse gas emissions. Total greenhouse gas emissions from the wastewater treatment plants using membrane bioreactor were mainly attributable to electricity consumption. On-site greenhouse gas emissions were relatively insignificant in this study.

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.

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.

Greenhouse gas emission by wastewater treatment plants of the pulp and paper industry – Modeling and simulation

Global warming and the greenhouse effect are two of the most important environmental problems. Carbon dioxide, methane, and nitrous oxide emissions are the main greenhouse gas emissions in wastewater treatment plants. In this study, the greenhouse gas emission sources in a wastewater treatment plant were determined. Direct (from fossil fuel combustion, methane emissions, and process emissions of the other greenhouse gases) and indirect emissions (primarily from electricity use) in the plant were monitored. The optimum influent characteristics and operating conditions have been defined by using Monte Carlo simulation to minimize the emissions. The results revealed that the highest direct greenhouse gas emission was observed in August with the value of 23.328 kg CO2‐eq d–1 and the lowest emission was 7.56 kg CO2‐eq d–1 measured in January. The aeration tank is a major source of greenhouse gas emissions. Indirect emission has occurred because of the anaerobic digester but the biogas has been cogenerated in the plant, so it has been ignored for the calculation. According to the simulation study, if the plant is operated under optimum operating conditions, it can emit the lowest amount of greenhouse gas emissions. The optimum removal values required for the minimum greenhouse gas emissions are 79% for chemical oxygen demand, 75% for biochemical oxygen demand, and 82% for total suspended solid. The optimum operating conditions for the aeration tank, which is the major source of emission, are 5.33 h of hydraulic retention time, 0.215 d of solid retention time, and 0.999 for food/microorganisms. © 2019 Society of Chemical Industry and John Wiley &amp; Sons, Ltd.

One of the greenhouse gas (GHG) emission resources is industrial wastewater treatment plants. In this study, on-site and off-site greenhouse gas emissions of an extended aeration activated sludge process in a meat processing wastewater treatment plant were estimated using a new developed approach based on the IPCC method. On-site emissions were regarded as the emissions related to the biochemical treatment process and microbial activity in the wastewater. On-site emissions were estimated from organic materials removal from wastewater and microbial mass activity. Biological oxygen demand (BOD) and chemical oxygen demand (COD) removal were considered as pollutant resources of carbon dioxide (CO2) and methane (CH4), respectively. Off-site emission was estimated from electricity consumption, chemical use and the sludge stabilization process. This paper aimed to determine and reduce on-site and off-site emissions for the extended aeration process in an industrial wastewater treatment plant. Modification of operating conditions was applied to reduce GHG emissions. The results revealed that electricity consumption was the major source of the greenhouse gas emissions for this process with a value of 6,002.77 kg CO2e/d. The minimization of total GHG emissions reached up to 17.1% by modifying the treatment process conditions.

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

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.

Industrial activities are one of the most important emission sources of greenhouse gases at a global level. The process of production, transportation, electricity consumption, and industrial wastewater are the four major components in producing greenhouse gases. Industrial wastewater management (collection, treatment, and disposal) results in direct emission of greenhouse gases (including carbon dioxide, methane, and nitrous oxide). Also, energy consumption in the wastewater treatment process causes indirect carbon dioxide emissions. The present study aimed to estimate the contribution of industrial wastewater treatment plants in Iran from this emission, in addition to identifying sources of greenhouse gas emissions in the industrial wastewater treatment plant and estimating greenhouse gas emissions from the industrial wastewater sector in Iran. In this research, the emission calculations were conducted by using the methodology of Intergovernmental Panel on Climate Change (IPCC) guidelines for calculating greenhouse gases emission. Based on the estimations performed in this study, 1,305.98 kt of CH4 were emitted directly from wastewater in 2017 in the entire industrial wastewater sector. Further, the results indicated that industrial wastewater treatment plants in Iran’s industrial parks generate 46.53 kt of CH4 directly and 259.5 kt of CO2 indirectly. According to the studies, the food industry, especially the industries involved in processing agricultural products (with 48.74 % of total methane emissions) has the highest greenhouse gas emissions in the country, followed by the paper production industry (with 27.46 % of total methane emissions) in the second place. One of the best strategies for reducing greenhouse gas emissions in industrial wastewater treatment plants is energy production from methane produced in large treatment plants and implementing necessary amendments in production processes to decrease wastewater production.

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.

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

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.

The activity of exploration and production in oil and gas industry is significant greenhouse gas (GHG) emission source. PT. XYZ is one of upstream oil and gas industry in Indonesia and it have large crude oil and gas potential with it reserves that not manage yet. Therefore, GHG emission potential from the activity of exploration and production in PT. XYZ is very large. This study is done for estimate GHG emission reduction potential in PT. XYZ from various activities. Emission inventory is the first step to estimate GHG released to atmosphere. Method of estimation use the method developed by American Petroleum Institute (API). This study considers three types of mitigation measures options, including technical options (scenario 1), behavior option (scenario 2), and policy option (scenario 3). Based on emission inventory, flare and oil storage tank are primary source of GHG emissions in PT. XYZ. Scenario 1 prefers control of GHG emissions in flare and storage tank as primary emission source. While others scenario prefers to control GHG emission from transportation sector. Scenario 1 has potential to reduce emissions by 48.3 %. While scenario 2, and 3 in sequences have potential to reduce emissions by 0.15%, and 0.52%. Emissions flare and oil storage tank can be reduced through the installation of flaring gas recovery unit and vapor recovery unit. Both are effective and efficient in reducing GHG emissions in PT. XYZ. In addition, all mitigation measures of transportation sector provide benefits even though the amount of GHG that can be reduced is not significant.

Abstract. Conferences, meetings and congresses are an important part of today's economic and scientific world. But the environmental impact, especially from greenhouse gas emissions associated with travel, can be extensive. Anthropogenic greenhouse gas (GHG) emissions account for the warming of the atmosphere and oceans. This study draws on the need to quantify and reduce greenhouse gas emissions associated with travel activities and aims to give suggestions for organizers and participants on possible ways to reduce greenhouse gas emissions, demonstrated on the example of the European Geography Association (EGEA) Annual Congress 2013 in Wasilkow, Poland. The lack of a comprehensive methodology for the estimation of greenhouse gas emissions from travel led to an outline of a methodology that uses geographic information systems (GIS) to calculate travel distances. The calculation of travel distances in GIS is adapted from actual transportation infrastructure, derived from the open-source platform OpenStreetMap. The methodology also aims to assess the possibilities to reduce GHG emissions by choosing different means of transportation and a more central conference location. The results of the participants of the EGEA congress, who shared their travel data for this study, show that the total travel distance adds up to 238 000 km, with average travel distance of 2429 km per participant. The travel activities of the participants in the study result in total GHG emissions of 39 300 kg CO2-eq including both outward and return trip. On average a participant caused GHG emissions of 401 kg CO2-eq. In addition, the analysis of the travel data showed differences in travel behaviour depending on the distance between conference site and point of origin. The findings on travel behaviour have then been used to give an estimation of total greenhouse gas emissions from travel for all participants of the conference, which result in a total amount of 79 711 kg CO2-eq. The potential for reducing greenhouse gas emissions by substituting short flights with train rides and car rides with bus and train rides is limited. Only 6 % of greenhouse gas emissions could be saved by applying these measures. Further considerable savings could only be made by substituting longer flights (32.6 %) or choosing a more central conference location (26.3 %).

Greenhouse gas (GHG) emissions were a major causal factor of global warming that further impacts climate change. This study aimed to inventory the sources of greenhouse gas emissions from the livestock sector in Bangka Belitung. The GHG emissions in the livestock sector was calculated using the Tier-2 method based on guidance from IPCC 2006. Secondary data were collected from multiple sources, including livestock population, enteric CH4 emission factors, and the production and management of local livestock manure. The results of the calculation of GHG emissions in Bangka Belitung from 2018-2022 showed a significant increase from 25.54 to 33.32 Gg CO2 eq, with an accumulation of 139.43 Gg CO2 eq over five years. Beef cattle became the largest contributor to GHG emissions, with enteric fermentation CH4 emissions of 104.34 Gg CO2 eq, accounting for 91.90% of the total CH4 emissions from enteric fermentation sources and 74.84% of the total GHG emissions in Bangka Belitung. The largest contributor to GHG emissions was 78.62% or 109.62 Gg CO2 eq from enteric fermentation sources of ruminants, while N2O emissions from manure management reached 29.10 Gg CO2 eq, and the smallest CH4 emissions were 0.70 Gg CO2 eq, sourced from livestock manure