Search results for "greenhouse gases."

Biotic oxidation of methane in landfills in boreal climatic conditions

2010

 This study focused on the biotic oxidation of methane in landfill covers as a technology for reducing greenhouse gas emissions from landfills, particularly those located in the boreal climatic zone. First, methane oxidation was studied in laboratory batch assays in a landfill cover soil consisting of a composted mixture of sewage sludge and chemical sludge which had been installed on the landfill surface 4-5 years earlier. Second, methane oxidation was studied using mechanically-biologically treated municipal solid waste (MBT residual) as a material for methane-oxidizing landfill covers both in continuously methane-sparged laboratory columns and in an outdoor pilot lysimeter. Finally, meth…

Editeur. Special Issue Strategies for Nitrous Oxide Emission Mitigation in Agrosystems". Agriculture-Basel

2022

Minimizing membrane bioreactor environmental footprint by multiple objective optimization.

2020

This paper presents a modelling study aimed at minimizing the environmental foot print of a membrane bioreactor (MBR) for wastewater treatment. Specifically, an integrated model for MBR was employed in view of the management optimization of an MBR biological nutrient removal (BNR) pilot plant in terms of operational costs and direct greenhouse gases emissions. The influence of the operational parameters (OPs) on performance indicators (PIs) was investigated by adopting the Extended-FAST sensitivity analysis method. Further, a multi-objective analysis was performed by applying the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The results show-up that the sludge …

Mathematical modelling of greenhouse gas emissions from membrane bioreactors: A comprehensive comparison of two mathematical models.

2018

Abstract This paper compares two mathematical models (Model I and Model II) to predict greenhouse gases emission from a University Cape Town (UCT) – membrane bioreactor (MBR) plant. Model I considers N 2 O production only during denitrification. Model II takes into account the ammonia-oxidizing bacteria (AOB) formation pathways for N 2 O. Both models were calibrated adopting real data. Model comparison was performed in terms of (i) sensitivity analysis (ii) best fit and (iii) model prediction uncertainty. On average 6% of factors of Model I and 9% of Model II resulted to be important. In terms of best fit, Model II had a better capability of reproducing the measured data. The average effici…

Comprehensive dataset of shotgun metagenomes from oxygen stratified freshwater lakes and ponds

2021

Stratified lakes and ponds featuring steep oxygen gradients are significant net sources of greenhouse gases and hotspots in the carbon cycle. Despite their significant biogeochemical roles, the microbial communities, especially in the oxygen depleted compartments, are poorly known. Here, we present a comprehensive dataset including 267 shotgun metagenomes from 41 stratified lakes and ponds mainly located in the boreal and subarctic regions, but also including one tropical reservoir and one temperate lake. For most lakes and ponds, the data includes a vertical sample set spanning from the oxic surface to the anoxic bottom layer. The majority of the samples were collected during the open wate…

Comparison of the greenhouse gas emissions of a high-rise residential building assessed with different national LCA approaches– IEA EBC Annex 72

2020

Introduction: The international research project IEA EBC Annex 72 investigates the life cycle related environmental impacts caused by buildings. The project aims inter alia to harmonise LCA approaches on buildings. Methods: To identify major commonalities and discrepancies among national LCA approaches, reference buildings were defined to present and compare the national approaches. A residential high-rise building located in Tianjin, China, was selected as one of the reference buildings. The main construction elements are reinforced concrete shear walls, beams and floor slabs. The building has an energy reference area of 4566 m2 and an operational heating energy demand of 250 MJ/m2a. An ex…

Comparison of Two Mathematical Models for Greenhouse Gas Emission from Membrane Bioreactors

2017

In this study two mathematical models (Model I and Model II), able to predict the nitrous oxide (N2O) and carbon dioxide (CO2) emission from an University Cape Town (UCT) – membrane bioreactor (MBR) plant, have been compared. Model I considers the N2O production only during the denitrification. Model II takes into account the two ammonia-oxidizing bacteria (AOB) formation pathways for N2O. Both models were calibrated adopting real data. Results highlight that Model II had a better capability of reproducing the measured data especially in terms of N2O model outputs. Indeed, the average efficiency related to the N2O model outputs was equal to 0.3 and 0.38 for Model I and Model II respectively.

Towards a new protocol for field measurements of greenhouse gases from wastewater treatment plant

2016

Emissions into the atmosphere of greenhouse gases (GHGs), i.e., carbon dioxide, methane and nitrous oxide from wastewater treatment plants are of increasing concern in the water industry. In order to produce useful and comparable information for monitoring, assessing and reporting GHG emissions from wastewater treatment plants, there is a crescent need for a general accepted methodology. This paper aims at proposing the first protocol for monitoring and accounting GHG emissions from wastewater treatment plants taking into account both direct and internal indirect emissions focusing on sections known to be major responsible of GHG emissions i.e. oxidation tanks and sludge digestion. The main…

Uncertainty and sensitivity analysis for reducing greenhouse gas emissions from wastewater treatment plants.

2020

Abstract This paper presents the sensitivity and uncertainty analysis of a plant-wide mathematical model for wastewater treatment plants (WWTPs). The mathematical model assesses direct and indirect (due to the energy consumption) greenhouse gases (GHG) emissions from a WWTP employing a whole-plant approach. The model includes: i) the kinetic/mass-balance based model regarding nitrogen; ii) two-step nitrification process; iii) N2O formation both during nitrification and denitrification (as dissolved and off-gas concentration). Important model factors have been selected by using the Extended-Fourier Amplitude Sensitivity Testing (FAST) global sensitivity analysis method. A scenario analysis h…

Origin of methane and light hydrocarbons in the gas manifestations of Greece.

2017

The geologic emissions of greenhouse gases (CO2 and CH4) give an important natural contribution to the global carbon budget. However, the contribution of these emissions to the global carbon cycle and their possible role on the climate change remain still poorly quantified (Guliyev and Feizullayev, 1997; Milkov, 2000; Etiope et al., 2015 and references therein). Methane, the most abundant organic compound in Earth's atmosphere, may be created either from existing organic matter or synthesized from inorganic molecules. Accordingly, it can be differentiated in two main classes: a) biotic (either microbial or thermogenic) and b) abiotic. For this study, 115 gas samples of fumarolic, thermal an…