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عنوان فارسی مقاله:
گازهای گلخانه ای بیوراکتورهای غشایی بسته توالی: مطالعه موردی بوته آزمایشی
عنوان انگلیسی مقاله:
Greenhouse gases from sequential batch membrane bioreactors: A pilot plant case study
سال انتشار : 2016
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مقدمه انگلیسی مقاله:
1. Introduction
During the last years the main goal of wastewater treatment plants (WWTPs) has become broader than simply to meet effluent standards for receiving water body protection: many efforts were spent with the aimto include reduction/control of greenhouse gases (GHGs) emission [1,2]. Indeed, WWTPs can produce GHGs such as nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4) [2]. GHG emissions from a WWTP can have a triple nature: direct, indirect internal and indirect external [3]. Direct emissions are mainly related to the biological processes (biomass respiration; biological nitrogen removal, etc); indirect internal emissions are associated with the electric consumptions and indirect external emissions are related to the other sources not directly controlled inside the WWTP (e.g., disposal of the excess sludge). Among the GHGs produced in a WWTP, N2O plays a key role in terms of climate change. Indeed, the global warming potential (GWP) of N2O is 298 times higher than that one of CO2 based on a time horizon of 100 years [4,5]. It is therefore crucial to identify potential anthropogenic sources of N2O in order to evaluate their relevance in the global N2O budget. The IPCC reports [6] have established that N2O emissions from WWTP account for approximately 3% ofthe total anthropogenic sources. Furthermore,the global N2O emissions from WWTP are expected to increase by approximately 13% between 2005 and 2020 [2]. Thus, it is imperative to better understand the core mechanisms connected with the N2O production and emission inWWTPs and identify the main operating conditions affecting its formation. During the last years, several efforts have been spent by the scientific community (inter alia Law et al. [2]; Kampschreur et al. [7]) with the aim to better understand processes and key operating factors promoting the N2O emission in WWTPs. The processes associated with biological nitrogen removal have been reported to be the key source of N2O emission [2,7,8]. Indeed, N2O can be produced during both nitrification (only by the ammonia oxidizing bacteria – AOB) and denitrification processes (during the NH2OH pathways of nitrifier denitrification and/or the heterotrophic denitrification pathway). In detail, N2O is an intermediate of the heterotrophic denitrification but it can also be produced during the ammonia oxidation process (nitrification) [9]. However, N2O formation mechanisms have not been completely elucidated yet [2,10]. Contrasting opinions have been reported in the technical literature regarding the prevalent pathway in N2O formation [2]. Furthermore, large variations in terms of measured N2O emissions have been reported for different WWTPs ranging between 0.01% and 1.8%, and in some cases even higher than 10% referring to the N-loading rate [7,11–14]. These variations have been mainly ascribed to the different operational conditions (e.g.,dissolved oxygen (DO) concentration, C/N-ratio, pH level, ammonium (NH4 +) loading rate, and NO2− accumulation) applied to the plants and also in different zones of the same plant [15,16]. Therefore, the fixed emission factors, applied to estimate N2O emissions from WWTPs, as suggested by the IPCC [6,17], may drive to erroneous quantifications. Indeed, fixed emission factors do not take into account the interrelationship between the process configurations and operating conditions. Therefore, the understanding of the key operating conditions or plant configurations affecting or promoting the N2O emissions is imperative for the reduction of N2O emissions.
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کلمات کلیدی:
Greenhouse Gas (GHG) Emissions | US EPA https://www.epa.gov/ghgemissions Feb 14, 2017 - molecule of gas Overview of Greenhouse Gases » Learn about the most important GHGs and opportunities for reducing emissions. What are greenhouse gases? | What's Your Impact whatsyourimpact.org/greenhouse-gases Greenhouse gases are a group of compounds that are able to trap heat (longwave radiation) in the atmosphere, keeping the Earth's surface warmer than it would be if they were not present.1 These gases are the fundamental cause of the greenhouse effect.2 Increases in the amount of greenhouse gases in the atmosphere ... Top stories Beans over beef: Cutting greenhouse gases starts on the plate, study shows National Post · 1 day ago Local View: Greenhouse gases not abundant, but potent Duluth News Tribune · 1 day ago More for Greenhouse gases Greenhouse Gas Emissions: Causes & Sources - Live Science www.livescience.com › Planet Earth Feb 10, 2015 - Behind the struggle to address global warming and climate change lies the increase in greenhouse gases in our atmosphere. A greenhouse ... Greenhouse Gases: Introduction | Monitoring References | National ... https://www.ncdc.noaa.gov/monitoring-references/faq/greenhouse-gases.php An introduction to the major greenhouse gases in the earth's atmosphere. The FAQ discusses the relative potency, concentration and expected atmopsheric ... Images for Greenhouse gases Image result for Greenhouse gases Image result for Greenhouse gases Image result for Greenhouse gases Image result for Greenhouse gases Image result for Greenhouse gases More images for Greenhouse gases Report images Greenhouse Gases - American Chemical Society https://www.acs.org/content/acs/en/climatescience/greenhousegases.html by ACS Home - Cited by 2 - Related articles What are “greenhouse gases?” The transparent windows of a greenhouse (or a car parked in the sunlight) transmit the warming visible rays of the sun, prevent ... Which Gases Are Greenhouse Gases? - American Chemical Society https://www.acs.org/content/acs/en/climatescience/greenhousegases/whichgases.html Some greenhouse gases occur naturally and enter the atmosphere as a result of both natural processes (such as decomposition of organic matter) and human ... Searches related to Greenhouse gases greenhouse gases list greenhouse gases effect examples of greenhouse gases greenhouse gases definition types of greenhouse gases is oxygen a greenhouse gas greenhouse gas emissions by country what causes greenhouse gases
