Terms Of Environmental Impact Research Articles

Potential Impact of Municipal Solid Waste: Case Study of Bahir Dar City, Ethiopia

This study was carried out to determine the potential impact of municipal solid waste in Bahir Dar city. The disposal of municipal solid waste in an open dumpsite in Bahir Dar has an environmental impact in terms of greenhouse gas emissions, eutrophication, and leachate. The quantity of greenhouse gases emitted from the open dumpsite of Bahir Dar city was determined by using IPCC default method. Currently around 148 tons/day waste is generated from Bahir Dar city and from these waste 58% of the waste is disposed into open dump site. From the waste disposal site 46Gg/year of greenhouse gas is emitted. The molecular formula that was determined from organic waste of the city is C24H36O13N. By using this molecular formula of the organic waste, the theoretical oxygen demand becomes 38.75 and then the eutrophication potential of organic waste generated from Bahirdar city was 0.0594 Kg N-equivalent or 59.4g N-equivalent. The average annual leachate resulting from the waste reaches 1,112mm per day. Bahir Dar city should start to implement 3R (Reduction, Reuse and Recycling) solid waste management options in order to reduce potential environmental impacts. For more investigation quantification of the other impacts associated with municipal solid waste is recommended.

Environmental assessment of carbon dioxide methanation process using mixed metal oxide and zeolite-supported catalysts by life cycle assessment methodology

Carbon dioxide methanation process is a well-known carbon dioxide utilization technology, not only on account of its ability to subside carbon dioxide in the atmosphere but also to produce methane, which is of serious industrial significance. Although this process is promising in terms of tackling greenhouse gases and global warming, it can, on the other hand, release toxic emissions into the atmosphere, rivers and soil during the process. At this point, life cycle environmental assessment emerges as a crucial tool to reveal the overall effects of this technology. This paper presents a life cycle assessment case study for carbon dioxide methanation process to evaluate all aspects of its environmental impacts. Different scenarios for this purpose were considered by changing catalyst types, namely, mixed metal oxide and zeolite-supported metal catalysts. The results showed that the toxic wastes formed and emissions released when using the Ni/Al 2 O 3 catalyst were less compared to the other cases. Not only did the change in material type in the catalyst affect the total emissions, but the catalyst conversion and selectivity had an influence on the life cycle impact of the system as well. Various power generation alternatives considering renewable and non-renewable sources were evaluated, while a combination of natural gas and wind turbines for the initial sources of power generation was found to perform better in terms of environmental impact. • CO 2 methanation on Ni/Al 2 O 3 catalyst is more environmentally-friendly. • Using natural gas for CO 2 capture emits fewer pollutants than using coal. • Conversion and selectivity factors can affect LCA results of a reaction-based process. • A mixture of natural gas power plants and wind turbines can reduce environmental impacts. • Perovskite solar cells show toxic effects on climate change and metal depletion.

Effect of Image Segmentation Thresholding on Droplet Size Measurement

Droplet size spectrum is a key factor in pesticide application because it affects the biological efficacy of a treatment in terms of target coverage, environmental impact in terms of evaporation, drift and run-off, and operator’s safety in terms of inhalation and dermal exposure. Droplet measurement methods based upon image analysis have to face the “binarization” or “segmentation” process, by which the objects of interest (the droplets) are extracted from the background. Segmentation is carried out by choosing appropriate threshold values, mostly based on the operator’s experience. In this study, images of droplets of an air induction nozzle TVI 8002 at four pressures (0.3, 0.5, 1.0, and 1.5 MPa) were obtained using the liquid immersion method. Each image was processed multiple times, firstly by using a “reference” threshold value based on the operator’s experience and then by using 11 different threshold values, chosen in the range of around ±5% of the reference threshold and based upon the average gray level of the image. For each threshold value, the corresponding spray parameters (volumetric diameters, mean diameters, Sauter diameters, and numeric diameters) were analyzed. The results showed that spray parameters had a statistically significant linear trend with respect to the threshold values in most cases. However, in absolute terms, variations were almost always less than 1.0% of reference values. This result allows considering the image acquisition system used in the present study as an automatic tool able to select the threshold according to the gray level of the image, making the whole segmentation process faster, more objective, and less dependent on the operator’s experience.

Environmental Impact of Ground Source Heat Pump Systems: A Comparative Investigation From South to North Europe

Ground Heat Exchangers (GHEs), buried in the ground either horizontally or vertically (in a borehole), are coupled with a heat pump to form a Ground Source Heat Pump (GSHP) system, which is a type of Renewable Energy System that exploits geothermal energy for space heating and cooling. GSHP systems are proposed as an alternative to conventional Air Source Heat Pumps (ASHPs) as they exhibit a higher efficiency. In this study, this difference in efficiency is tested in order to determine how the systems perform in terms of environmental impact. Three types of GSHP systems (with different GHE configuration), each compared to ASHPs, undergo a Life Cycle Analysis using the ReCiPe method from both mid-point and end-point perspectives. The heating and cooling loads required for a single residential building of area 220 m2, with nearly Zero Energy Building technical characteristics, is used as a Functional Unit, for seven cases (locations/countries) from South to North Europe. Additionally, a Simple Payback Period method is employed to investigate the CO2 payback time for the GSHPs. It is concluded that the use of GSHP systems in residential buildings, even with nZEB (nearly Zero Energy Buildings) characteristics of low heating/cooling demand, can be a more environmentally friendly solution than that of an ASHP system, depending on the factors affecting the system, namely the ground thermal characteristics, the heating/cooling demand, the heating/cooling peak loads and electricity mix.

Effect of feeding fresh forage plantain (Plantago lanceolata) or ryegrass-based pasture on methane emissions, total-tract digestibility, and rumen fermentation of nonlactating dairy cows

Plantain (Plantago lanceolata) is an herb used to reduce the forage deficit of ryegrass-based pastures during the summer. This herb is being promoted for its reduced environmental impact in terms of nitrogen emissions, particularly reducing urinary nitrogen. However, the effect of plantain on emissions of enteric CH4, the main greenhouse gas produced from ruminant-based production systems, is not known. The aim of the present trial was to determine CH4 emissions and rumen fermentation characteristics of nonlactating dairy cows fed 100% plantain (PLT) or 100% perennial ryegrass (RG; Lolium perenne) in 2 experiments (E1 and E2). The forages were in a vegetative growth stage in E1 and were in a reproductive growth stage in E2. Methane emissions from 16 cows in each experiment were measured in respiration chambers for 2 d. Methane emissions per unit of dry matter intake (CH4 yield) were 15 and 28% less for cows fed PLT than those fed RG in E1 and E2, respectively. Dry matter digestibility of PLT was 7 and 27% less than that of RG in E1 and E2, respectively, and CH4 per unit of dry matter digested was similar for PLT and RG in both experiments. There were only minor (but some significant) differences in rumen fermentation characteristics between cows fed PLT and RG in both experiments. In conclusion, CH4 yield was lower for cows fed PLT compared with those fed RG in both experiments and this reduction was largely explained by the lesser dry matter digestibility of PLT.

Advances in the circularity of end-of-life fibre-reinforced polymers by microwave intensification

The growing use of fibre-reinforced polymer (FRP) composites and the increasing global generation of FRP waste implies an urgent need to develop a circular economy strategy to promote the recovery of fibres and the valorisation of resins. This review paper analyses the current scenario of FRP recycling technologies and evaluates the potentials of microwave-assisted heating as a technology to provide an intensification in terms of energy-efficiency, selective heating and processing speed, as well as an electrified thermal treatment for FRP recycling. The paper presents an overview of the estimated FRP production and waste generation per sector in the coming decennia and the current and envisioned international legislation related to the management of end-of-life FRP. The paper also discusses the strong and weak points of the existing FRP recycling technologies, their readiness level and overall environmental impact in terms of equivalent CO2 emissions. Furthermore, the emerging microwave-assisted FRP recycling technology is evaluated, showcasing the potentials and obstacles for its implementation and the potential end-use and characteristics of the recycled components. A literature survey on the existing prototypes, MW-assisted waste-to-value processes and reported energy demand is conducted. Finally, the required resources and framework for the consolidation of the MW-assisted FRP recycling as an alternative and economically viable technology are assessed.

Environmental and economic performances of incorporating Fenton-based processes into traditional sludge management systems

Municipal and industrial wastewater treatment plants produce a tremendous amount of sludge containing organic and toxic components. One of the advanced oxidation processes (AOP) - Fenton process has demonstrated great prospect in reduction of sludge organics and toxicity. Fenton pretreatment could ameliorate the sludge dewaterability and biodegradability for anaerobic digestion (AD) process, and enhance the sludge lower heating value for incineration process, thus stimulating sludge dewatering, reduction and energy recovery. However, doubts remain about whether the incorporation of the Fenton process into the traditional sludge management systems brings environmental benefits. Hence, a life cycle environmental impact calculation model was established for sludge with various organic contents (60%, 70%, 80%) under the effect of Fenton and US/UV/Electro-Fenton processes. Noteworthy mitigation of environmental load was observed for the Fenton process coupled with incineration system, which involves high dewatering demand. Conversely, as for the AD system with high biomass transformation rate, Fenton process failed to attain the assumed promotion of environmental benefit. Hydrogen peroxide (H2O2) prominently attributed to the weakness of Fenton process combined with AD (F-AD) scenario, compared with the AD scenario in terms of environmental impact. Summarily, the F-AD scenario acts as the preponderant system when weighing up the pros and cons of environmental impact, energy balance and life cycle cost. Contrary to the mainstream view, the proven technical advantages of Fenton process cannot compensate for the additional environmental loads in the life cycle of sludge. It provides valuable reflection for environmental managers and scholars that we should be more cautious in the application of cutting-edge technologies.

LCA to Estimate the Environmental Impact of Dairy Farms: A Case Study

Intensive farming is responsible for extreme environmental impacts under different aspects, among which global warming represents a major reason of concern. This is a quantitative problem linked to the farm size and a qualitative one, depending on farming methods and land management. The dairy sector is particularly relevant in terms of environmental impact, and new approaches to meeting sustainability goals at a global scale while meeting society’s needs are necessary. The present study was carried out to assess the environmental impact of dairy cattle farms based on a life cycle assessment (LCA) model applied to a case study. These preliminary results show the possibility of identifying the most relevant impacts in terms of supplied products, such as animal feed and plastic packaging, accounting for 19% and 15% of impacts, respectively, and processes, in terms of energy and fuel consumption, accounting for 53% of impacts overall. In particular, the local consumption of fossil fuels for operations within the farm represents the most relevant item of impact, with a small margin for improvement. On the other hand, remarkable opportunities to reduce the impact can be outlined from the perspective of stronger partnerships with suppliers to promote the circularity of packaging and the sourcing of animal feed. Future studies may include the impact of drug administration and the analysis of social aspects of LCA.

Life cycle assessment and circularity evaluation of the non-medical masks in the Covid-19 pandemic: a Brazilian case.

This paper aims to evaluate the life cycle impact and the circularity of face masks to support government public policies in extreme consumption of these products as in the case of the Covid-19. The reference case was the Brazilian context for using and consuming Personal Protective Equipment (PPE). Two types of face masks were defined for analysis: handmade reusable face masks made with cotton fabric and single-use face masks made with nonwoven fabric. To achieve this goal, the Life Cycle Assessment (LCA) steps following ISO 14040 and the Material Circularity Indicator (MCI) by the Ellen Macarthur Foundation were applied. The results obtained show that the reuse of face masks has a better environmental performance over five uses. The comparative analysis between the ReCiPe 2016 and IMPACT World+ methods shows that the impact categories linked to human health are the most important in terms of environmental impact. Nevertheless, the trend toward improved environmental performance for the handmade reusable face mask has continued. The possibility of recycling shows that the reintegration of material after the use of the product could improve the environmental performance of both face masks. Finally, the reuse increases the circularity of cotton fabric masks compared to nonwoven fabric masks according to MCI. In this way, it is possible to observe that the handmade reusable face mask has a better environmental performance and a higher circularity than the single-use face mask. Thus, the results of the environmental performance and circularity of the face masks may support the decision of government agents to guide the public in the use of face masks, not only contributing to the protection of health against Covid-19, but also reducing the environmental impact of PPE. Furthermore, the methodological steps adopted in the study gives greater reliability in the conclusions obtained.

Mechanical Characteristics of GGBFS/FA-Based Geopolymer Concrete and Its Environmental Impact

Geopolymer concrete is considered to be one of the best alternatives to portland cement concrete, partially or totally, not only because it decreases the CO2 emissions released during ordinary portland cement (OPC) production, but also due to its acceptable mechanical and durability properties. This study presents the experimental results of using fly ash (FA) and ground granulated blast-furnace slag (GGBFS) on fresh and hardened geopolymer concrete properties, considering the effects of several parameters such as binder type and content, alkaline binder ratio, molarity, Si/OH ratio, cement ratio in the binder, water addition, and curing temperature. These parameters were studied over a wider range than in previous research using local by-product waste to determine the validity of the additives for massive production of geopolymer concrete. The studied properties were the slump, 7- and 28-day cube compressive strength, tensile strength, and modulus of elasticity. For all studied mixes, the increase of the binder content, sodium hydroxide concentration, and cement ratio of the binder enhanced the concrete properties, whereas the increase of the alkaline binder ratio, Si/OH ratio in the solution, and additional water decreased the concrete properties. An increase of curing temperature from 30°C to 90°C improved the fly ash–based geopolymer concrete mechanical properties by an average of 35%; in contrast, the same increase in temperature decreased the concrete mechanical properties of GGBFS-based geopolymer concrete by an average of 22%. Equations for tensile strength and modulus of elasticity in terms of compressive strength were proposed and were compared with equations from standards and equations previously proposed in the literature. Finally, the environmental impact in terms of CO2 emissions was found to be on average 90% less than that of conventional concrete of the same grade.

Ductility Consideration for a Sustainable RC Building

In terms of sustainable and green society, a building structure needs to be functional, resilient, and environmental friendly at a post-earthquake event. During a seismic event, the performance of the building gets drastically deteriorated. In terms of safety and serviceability, it is required to evaluate actual capacity of the building at various levels of earthquake in terms of ductility and strength. In the present study, a five-storied residential building has been considered and pushover analysis has been performed to evaluate capacity of the building at various intensity of earthquake with return periods of 475 year, 950 year, 2475 year, and 4950 year. Both the ductility and strength of the building have been evaluated with variation of properties of materials. It has been observed that improvement of ductility can be suitably achieved by selecting a specific grade of steel and concrete. However, the same should also be judged in terms of post-earthquake repair consideration in terms of environmental impact.

Recent Advances in Greener and Energy Efficient Alkene Epoxidation Processes

The chemical industry is considered to be one of the largest consumers of energy in the manufacturing sector. As the cost of energy is rising rapidly, coupled with the increasingly stringent standards for the release of harmful chemicals and gases into the environment, more attention is now focused on developing energy efficient chemical processes that could significantly reduce both operational costs and greenhouse gas emissions. Alkene epoxidation is an important chemical process as the resultant epoxides are highly reactive compounds that are used as platform chemicals for the production of commercially important products for flavours, fragrances, paints and pharmaceuticals. A number of epoxidation methods have been developed over the past decade with the ultimate aim of minimising waste generation and energy consumption. In this review paper, some of the recent advances in epoxides synthesis using energy efficient processes are discussed. The epoxidation methods may provide sustainability in terms of environmental impact and energy consumption.

Applying principles of EIA post-project analysis in the context of suburban infrastructure development

Residential, commercial, and infrastructural construction is a worldwide phenomenon that is monitored and evaluated in various details in different countries in terms of environmental impact. The prediction verification approach in the sense of principles of post-project analysis (PPA) within the EIA process for a residential complex was performed in this study. Re-analyses for selected environmental factors were done, the results of which were compared with reference values measured, modelled, or predicted during the EIA process. Hydro chemical changes and noise levels were selected as the most important factors. The results of the comparison of individual predictions and measurements of noise levels indicate the accuracy of former EIA outcomes. However, it is possible to identify an ever-increasing rate of noise level loading, which is caused by an overall cumulative effect, due to which the predicted values will most probably be exceeded in upcoming years. The results of the comparison of hydro chemical parameters show certain changes after the implementation of the project for some measured factors, such as water saturation by oxygen or pH. In some parts of the monitored water profile, significantly higher values of chlorine ions, sulphates, or surfactants were measured. Results show that the prediction and conclusions regarding selected parameters of EIA evaluation were accurate for the construction phase and the first year’s use of the residential complex; however, they could not precisely identify medium to long-term cumulative effects. Similar studies in the sense of EIA PPA principles focuses on urban development are an opportunity for improving predictions within the EIA process and from the lessons gain more sustainable development could be achieved.

Life cycle assessment of a novel blast furnace slag utilization system

A novel system was proposed to realize the high value-added utilization of blast furnace slag. In this study, a comprehensive analysis concerning energy consumption, environmental impact and economic cost of the system was conducted based on the perspective of life cycle. Considering the serious situation of global warming, CO2 emission cost was also included. Main contributors in terms of environmental impact, energy consumption and economic cost were traced through contribution analysis. Global warming potential was the most prominent environmental issue (contributing 65.71% to total impact) and material cost offered the largest economic burden (contributing 90.57% to total cost). However, the adsorption capacity of two products offset total CO2 emission to −6103.62 kg·tslag−1 and decreased total economic cost to 352.26 $·tslag−1, turning the major limitation into a great opportunity. Most energy was consumed in upstream production of chemicals and only 3.18% of the total energy consumption came from the downstream utilization process. According to the sustainability evaluation among three processes, pretreatment performed worst and the hydrotalcite-like compounds synthesis process best. Additionally, sensitivity analysis indicated that overall performance of the system could be efficiently improved by reducing hydrochloric acid consumption. Analysis results in this study exhibited the huge potential of the system in emission reduction and could provide guidance for further improvement.

Environmental impact hotspots of an integrated wet anaerobic digestion through life cycle assessment for food waste management

Abstract Wet anaerobic digestion (AD) is one of the most widely implemented systems that valorize food waste (FW) for biogas production. Despite the undeniable AD benefits, the environmental impact of AD could differ depending on the biogas systems used. This article examines the hotspots on environmental impact of FW management such as global warming and ozone depletion based on integrated wet AD by utilizing a life cycle assessment approach. The integrated wet AD scenario in this study is a technology that combines wet AD, aerobic windrow composting and a landfill. The scenario modelling was accomplished by applying GaBi v6.0 software with 1 ton of pre-treated FW as a functional unit, and the analysis was based on the ReCiPe (H) v1.07 characterization technique. At the midpoint level, it was observed that the integrated wet AD presented the most significant environmental impact in terms of ionizing radiation (1.4×100 kg U235-eq), followed by water depletion (1.11×103 m3-eq), global warming (6.27×102 kg CO2-eq), fossil depletion (2.18×102 kg oil-eq) and human toxicity (2.89×101 kg 1,4-DB-eq). The disadvantages of the integrated wet AD in global warming were associated with CO2, CH4, and N2O emissions from the energy used for process treatment and fossil fuels during transportation, primarily in landfill activities, followed by wet AD and aerobic windrow composting stages. Regarding single-score indicators, integrated wet AD presented the most resource damaging impact (3.50×103 Pt), mainly due to fossil depletion. This study emphasizes the necessity of reducing the life cycle consequences related to CH4, N2O and NH3 emissions throughout the decomposition process in integrated wet AD, particularly landfill activities.

Partial replacement of soybean meal with soybean silage and responsible soybean meal in lactating cows diet: part 2, environmental impact of milk production

Soybean meal, the main protein source for livestock in Italy, is associated with high environmental impact in terms of land use change. Thus alternative protein sources are advisable. The study aimed to evaluate through a Life Cycle Assessment (LCA) approach the environmental impact of milk production systems characterised by different diets of lactating cows including different sources of soybean. Four scenarios were identified: (1) conventional soybean meal (CON), (2) conventional soybean meal and soybean silage (SBS), 3) responsible soybean meal defined by the FEFAC guidelines (CON + RSM), (4) soybean silage and responsible soybean meal (SBS + RSM). Inventory data were derived from a previous in vivo trial on lactating cows and farmer interviews. Secondary data were obtained from the ECOINVENT® and the Agri-footprint databases. The LCA was performed using the SimaPro V 8.3. Soybean silage showed higher global warming potential (GWP), marine eutrophication and human toxicity compared with lucerne hay, the most utilised self-produced protein feed, due to the high contribution of mechanical operations in the field. The GWP of milk (kg CO2eq/kg FPCM) decreased from 1.38 of the CON scenario to 1.17 of SBS and 1.13 of CON + RSM; the best result was obtained by combining soybean silage with responsible soybean meal: 1.01. Furthermore, the scenarios using RSM reduced agricultural land occupation and natural land transformation. The inclusion of SBS and RSM is an interesting option to reduce environmental impact of milk production, maximising yields of DM and CP per hectare and representing an alternative protein source. HIGHLIGHTS The ration of dairy cows represents one of the main causes of the environmental impact of the livestock sector due to the impact for feed production (forage and concentrate) Feeding soybean meal as protein source has high environmental impact since it is linked with deforestation in South America Alternative protein sources like soybean silage and soybean meal produced sustainably could reduce the environmental impact of the sector

A Comprehensive Survey on Climate Optimal Aircraft Trajectory Planning

The strong growth rate of the aviation industry in recent years has created significant challenges in terms of environmental impact. Air traffic contributes to climate change through the emission of carbon dioxide (CO2) and other non-CO2 effects, and the associated climate impact is expected to soar further. The mitigation of CO2 contributions to the net climate impact can be achieved using novel propulsion, jet fuels, and continuous improvements of aircraft efficiency, whose solutions lack in immediacy. On the other hand, the climate impact associated with non-CO2 emissions, being responsible for two-thirds of aviation radiative forcing, varies highly with geographic location, altitude, and time of the emission. Consequently, these effects can be reduced by planning proper climate-aware trajectories. To investigate these possibilities, this paper presents a survey on operational strategies proposed in the literature to mitigate aviation’s climate impact. These approaches are classified based on their methodology, climate metrics, reliability, and applicability. Drawing upon this analysis, future lines of research on this topic are delineated.

Understanding Sustainability of Construction Products: Answers from Investors, Contractors, and Sellers of Building Materials

Preventing environmental degradation and climate changes are some of the primary challenges of our civilization. Changes to the construction sector, which consumes vast amounts of raw materials, emits significant amounts of greenhouse gas and significant amounts of waste, are very important to reduce emissions and stop negative environmental changes. Regardless of the type of goal, an essential element to achieve it is understanding the purpose and tools necessary to implement appropriate and efficient solutions. This paper presents the survey results on understanding issues related to assessing construction products, including their environmental impact. The survey was conducted among professional groups related to construction, i.e., 181 investors, 522 contractors, and 116 sellers of construction products from various regions of Poland. Questions concerning thermal insulation materials and the external thermal insulation composite system (ETICS), the most widely used solution in the EU for the improvement of thermal performance of buildings, were asked. The obtained results indicate that the knowledge of the basic requirements of construction works under the Construction Products Regulation (CPR) is not too high (the share of correct answers was respectively 33.5%, 23.2%, and 16.2% in contractors, sellers, and investors groups). Similarly, the awareness of the tested, related to the environmental burden in terms of GWP of insulation materials and components of ETICS, should be assessed (49.7% of investors, 57.1% sellers of construction products, and 76.4% contractors indicated the thermal insulation material as the ETICS component with the highest environmental impact in terms of GWP). The obtained research results indicate the need for further education for evaluating construction products and sustainability.

Synergetic effect of UiO-66 and plasmonic AgNPs on PET waste support towards degradation of nerve agent simulant

• PET bottles served as substrate for UiO-66 growth and further Ag NPs deposition. • We optimized AgNPs deposition for pores availability for paraoxone adsorption. • Deposition of AgNPs provide plasmonic activity to PET@UiO-66. • PET@UiO-66Ag degraded quantitively paraoxone for 1 h under visible light. • AgNPs synergistically enhance Lewis’s acid centers of UiO-66 for degradation of paraoxon-ethyl. The combination of metal–organic frameworks (MOFs) possessing porosity and catalytic activity with plasmonic nanoparticles (PNPs) defines a new paradigm in photocatalytic degradation of ecotoxicants. Herein, we designed a novel composite derived from a polyethylene terephthalate (PET) waste, MOF – UiO-66, and silver nanoparticles (AgNPs) to degrade paraoxon as a nerve agent simulant under plasmon excitation. The prepared material was characterized by spectroscopic: XRD, UV–Vis, FT-IR, XPS, microscopic: SEM (EDX), TEM and ICP-MS, TGA, BET analysis, and NH 3 TPD techniques. We found the balance between pore availability of UiO-66 for paraoxon adsorption, plasmonic enhancement, and the cost of the final composite. In the case of PET@UiO-66-Ag25, paraoxon is degraded for 1 h with ∼ 95 % efficiency under 455 nm. The synergetic degradation mechanism of UiO-66 and AgNPs was proved by experiments with different wavelengths of illumination, PET@Ag, and control reaction of Fisher esterification. The synergetic effect is explained by weakening the chemical bonds in the transition state between the Zr site (Lewis’s acid centers) and paraoxon via plasmon excitation and energy transfer. Moreover, PET@UiO-66-Ag25 is overperforming other materials in terms of environmental impact, easiness of preparation, visible light usage, high apparent quantum yield, and recycling performance.

Environmental assessment of four waste cooking oil valorization pathways.

Global waste is expected to grow substantially by 2050, therefore, defining an effective waste management strategy is a crucial topic for both industry and academia. Nowadays, food and green waste, in particular, represent a large share of the total waste production. All this considered, effectively processing and eventually reusing materials such as waste cooking oil is of paramount importance. This study investigates the potential environmental impact and the primary energy consumption for three waste cooking oil valorization pathways i.e. biodiesel, direct burning fuel, additive for recycling aged-asphalt, as well as a new application, i.e. phase change material, compared to their specific more common alternative based on a cradle-to-gate approach. The aim is to identify and recommend the most advantageous alternative in terms of environmental impact. Results showed that the waste cooking oil has a lower impact in all comparisons made, except as phase change material. The less effective performance in some cases was compensated by the waste oil entry as a burden-free resource under an attributional model. The best profile of the waste cooking oil is as direct burning fuel. However, the binder asphalt substitution is highly recommended due to the nature of the application. The major obstacles to the waste cooking oil usage are the limited stock, composition and quality variability, and the difficulty of proper collection.