Search results for "GREEN"
showing 10 items of 1660 documents
Assessing changes in eco-productivity of wastewater treatment plants: The role of costs, pollutant removal efficiency, and greenhouse gas emissions
2018
Abstract Improving eco-efficiency of wastewater treatment plants (WWTPs) has been identified as being essential for achieving urban sustainability. Several previous papers have evaluated the eco-efficiency of WWTPs using data envelopment analysis (DEA) models. However, those models provided only a static assessment in that they ignored possible fluctuations over time within each plant. To overcome this temporal limitation, this paper evaluates dynamic eco-efficiency (changes in eco-productivity over time) of WWTPs using the dynamic weighted Russell directional distance model (WRDDM). This approach allows one to obtain an eco-productivity change index for each major component of the WRDDM mo…
Greenhouse gases from membrane bioreactors: New perspectives on monitoring and mathematical modeling
2020
Abstract The awareness that the wastewater sector represents a significant source of greenhouse gas emission has increased, and is the awareness is evident based on the numerous research papers published in technical literature in the last 10 years. This chapter is aimed at providing a timely overview on greenhouse gas production and emission from membrane bioreactors. Specifically, this chapter dedicates particular attention to nitrous oxide (N2O), considering both experimental and mathematical modeling approaches. Referring to the experimental data, the observed results highlighted the significant contribution of the aerated compartments toward nitrous oxide emission as well as the import…
Evaluation of energy performance of drinking water treatment plants: Use of energy intensity and energy efficiency metrics
2018
Abstract One of the United Nations Sustainable Development Goals is to provide access to safe and clean drinking water. However, treating raw water in facilities currently involves using a non-negligible amount of energy, and the fossil fuels used are both expensive and emit greenhouse gases when combusted. Previous studies have evaluated the energy performance of drinking water treatment plants by estimating the amount of energy consumed per volume of water. However, such studies have not accounted for differences between treatment technologies and have assumed a common standard water treatment technology. To overcome these limitations, this study employed metafrontier data envelopment ana…
Hydrogen Dark Fermentation for Degradation of Solid andLiquid Food Waste
2021
The constant increase in the amount of food waste accumulating in landfills and discharged into the water reservoirs causes environment pollution and threatens human health. Solid and liquid food wastes include fruit, vegetable, and meat residues, alcohol bard, and sewage from various food enterprises. These products contain high concentrations of biodegradable organic compounds and represent an inexpensive and renewable substrate for the hydrogen fermentation. The goal of the work was to study the efficiency of hydrogen obtaining and decomposition of solid and liquid food waste via fermentation by granular microbial preparation (GMP). The application of GMP improved the efficiency of the d…
Salt accumulation and effects within foliage of Tilia × vulgaris trees from the street greenery of Riga, Latvia
2020
International audience; Green infrastructures within sprawling cities provide essential ecosystem services, increasingly undermined by environmental stress. The main objective in this study was to relate the allocation patterns of NaCl contaminants to injury within foliage of lime trees mechanistically and distinguish between the effects of salt and other environmental stressors. Using field material representative of salt contamination levels in the street greenery of Riga, Latvia, the contribution of salt contaminants to structural and ultrastructural injury was analyzed, combining different microscopy techniques. On severely salt-polluted and dystrophic soils, the foliage of street lime …
The impact of landfills on the air quality of towns: A simple heuristic model for the city of Palermo
2009
In this study, the landfill of Palermo, is investigated as a potential source of the unusual methane concentrations found in the urban context. The source for these pollution episodes is identified by means of a simple heuristic method. A cross-correlation analysis between wind data and methane concentration levels is also used to confirm the hypotheses formulated. Doppler Sound Detection And Ranging (SODAR) measurements are used to investigate the air masses dynamics at the landfill, in order to better support the adopted assumptions. This interpretative method can be adopted in the first assessment stages of the environmental site performance in order to single out the candidate pollution…
Wave Energy Assessment and Performance evaluation in Mediterranean Sea
2020
The paper proposes a revolutionary device for the utilization of a new entry of renewable energy sources: sea wave. This technology is based on linear generators, able to converts directly a linear motion into electrical output, limiting to minimum the chain of energy conversion. A preliminary feasibility assessment considers a case study applied in Lampedusa, a small island in the Mediterranean Sea. Economic and environmental evaluations are here reported.
Optimizing Fuel Consumption and Pollutant Emissions of a Spark Ignition Engine for Eco-driving Applications
2018
VPPC 2018, Vehicle Power and Propulsion Conference, Chicago, ETATS-UNIS, 27-/08/2018 - 30/08/2018; The transportation sector is a major contributor to both air pollution and greenhouse gas emissions. While optimizing fuel consumption reduces CO2 emissions, it can increase fuel-rich operation and cause higher HC and CO emissions. A simplified emissions model is thus introduced in order to account for the impact of air/fuel ratio on both the exhaust concentration of regulated pollutants and the catalyst efficiency. This model is used to solve the eco-driving problem with dynamic programming and a weighted objective function. An emission-centered and a consumption-centered scenario are compare…
Arundo Donax Fibers as Green Materials for Oil Spill Recovery
2020
Oil spillage is considered one of the most devastating forms of pollution, for its effect on the environment, particularly on aquatic life. This kind of disaster can impact in two ways, directly caused by the polluting spilled oil or due to the cleanup process. In fact, oil floating on water does not allow sunlight to pass through and its toxicity puts the life of aquatic animals at risk. Furthermore, other factors can also contribute to this damage. In fact, a wrong oil recovery system can add a further pollution level. Polymer sorbents used for the oil spill recovery, if not properly treated, increase the level of marine and ground pollution. For this reason, in the last years, green mate…
Towards A New Decision Support System for Design, Management and Operation of Wastewater Treatment Plants for the Reduction of Greenhouse Gases Emiss…
2015
The increasing attention paid to the environment has led to a reduction in the emissions from wastewater treatment plants (WWTPs). Moreover, the increasing interest in the greenhouse gas (GHG) emissions from WWTPs suggests that we reconsider the traditional tools used for designing and managing WWTPs. Indeed, nitrous oxide, carbon dioxide and methane can be emitted from wastewater treatment, significantly contributing to the greenhouse gas (GHG) footprint. The reduction of energy consumption as well as GHG emission are of particular concern for large WWTPs which treat the majority of wastewater in terms of both volume and pollution load. Nowadays, there is an increasing need to develop new …