Oxidant Formation Potential Research Articles

Predicting environmental impacts of smallholder wheat production by coupling life cycle assessment and machine learning

Wheat grain production is a vital component of the food supply produced by smallholder farms but faces significant threats from climate change. This study evaluated eight environmental impacts of wheat production using life cycle assessment based on survey data from 274 households, then built random forest models with 21 input features to contrast the environmental responses of different farming practices across three shared socioeconomic pathways (SSPs), spanning from 2024 to 2100. The results indicate significant environmental repercussions. Compared to the baseline period of 2018–2020, a similar upward trend in environmental impacts is observed, showing an average annual growth rate of 5.88 % (ranging from 0.45 to 18.56 %) under the sustainable pathway (SSP119) scenario; 5.90 % (ranging from 1.00 to 18.15 %) for the intermediate development pathway (SSP245); and 6.22 % (ranging from 1.16 to 17.74 %) under the rapid economic development pathway (SSP585). Variation in rainfall is identified as the primary driving factor of the increased environmental impacts, whereas its relationship with rising temperatures is not significant. The results suggest adopting farming practices as a vital strategy for smallholder farms to mitigate climate change impacts. Emphasizing appropriate fertilizer application and straw recycling can significantly reduce the environmental footprint of wheat production. Standardized fertilization could reduce the environmental impact index by 11.10 to 47.83 %, while straw recycling might decrease respiratory inorganics and photochemical oxidant formation potential by over 40 %. Combined, these approaches could lower the impact index by 12.31 to 63.38 %. The findings highlight the importance of adopting enhanced farming practices within smallholder farming systems in the context of climate change. Spotlights•China's smallholder wheat farming is increasingly exposed to climate threats, risking resource depletion and pollution•Increasing eco-impacts of smallholder wheat farming could be mitigated by regulated fertilizer use and straw recycling•Life cycle assessment combined with machine learning targets future environmental impacts in dynamic climate scenarios•The study offers actionable policy advice for sustainable smallholder wheat farming practices•Future work may probe machine learning's role in forecasting smallholder production behaviors and farming decision aid

Effect of diets with different crude protein levels on ammonia and greenhouse gas emissions from a naturally ventilated dairy housing

Less crude protein (CP) in the diet can reduce nitrogen excretion of dairy cattle and lower their ammonia (NH3) and nitrous oxide (N2O) formation potential. The diet composition might also affect emissions of methane (CH4) and carbon dioxide (CO2). However, previous studies did not investigate the effect of diets with different CP levels that are customary practice in Switzerland on NH3 and greenhouse gas emissions on a practical scale. In a case-control approach, we quantified the emissions (NH3, N2O, CH4, CO2) in two separate but identical compartments of a naturally ventilated cubicle housing for lactating dairy cows over six days by using a tracer ratio method. Cows in one compartment received a diet with 116 g CP per kilogram dry matter (DM), in the other compartment with 166 g CP kg−1 DM. Subsequently, diets were switched for a second 6-day measurement phase. The results showed that the diet, aside from outside temperature and wind speed in the housing, was driving NH3 and N2O emissions. NH3 and N2O emission reduction per livestock unit (LU) was on average 46 % and almost 20 %, respectively, for the diet with low CP level compared to the higher CP level. In addition, strong relationships were observed between the CP content of the diet, N excretion in the urine and the milk urea content. An increased temperature or wind speed led to a clear increase in NH3 emissions. Differences in CH4 and CO2 emissions per LU indicated a significant influence of the diet, which cannot be attributed to the CP content. Our herd-level study demonstrated that a significant reduction in NH3 and N2O emissions related to LU, energy-corrected milk as well as DM intake can be achieved by lowering the CP content in the diet.

Environmental assessment of road transport fueled by ammonia from a life cycle perspective

Renewable energy penetration into the electricity market has been increasing over the last decades; however, it is a different story in the transport sector. Fossil fuels are still predominant; therefore, several alternatives are being studied to attain a low-carbon, more sustainable transport and, consequently, a sustainable society. Ammonia has the potential to be a viable option, and it is critical to study its environmental profile in this early phase to appraise its sustainability as a fuel for passenger road transportation. This work aimed to develop a life cycle assessment of an ammonia-fueled internal combustion engine passenger car from the cradle to the grave, considering 1 km traveled as the basis for comparison. The product system under study included four stages: (i) vehicle, (ii) infrastructure, (iii) energy production, and (iv) operation. Life cycle inventory data related to vehicle operation, specifically ammonia combustion, resulted from various simulations of a model that considered the effect of different operation modes and vehicle emission control strategies, which resulted in nine configurations. The results show that rich mixtures (with an equivalence ratio of 1.1) help to reduce both nitrogen oxides (NOX) and nitrous oxide (N2O) emissions. As for unburnt ammonia (NH3), the after-treatment system drastically diminishes these and NOX emissions. Data on infrastructure and other upstream processes was taken from the Ecoinvent 3.7.1 database, and the ammonia production was based on the life cycle inventory from previous research. The life cycle impact assessment was performed on OpenLCA software implementing the ReCiPe2016 Midpoint (H) v1.13 methodology. On average, per 1 km traveled in an ammonia-based ICEV represents 0.098 kg CO2-eq for global warming potential (GWP100), 30.755 g oil-eq for fossil depletion potential (FDP), 38.974 mg P-eq for freshwater eutrophication potential (FEP), 8.907 μg CFC-11-eq for ozone depletion potential (ODP), 0.906 g NMVOC-eq for photochemical oxidant formation potential (POFP), and 1.029 g SO2-eq for terrestrial acidification potential (TAP). These results show a significant reduction, above −70%, for GWP100, FDP, and ODP compared with the same vehicle fueled on gasoline.

Template for Evaluating Cradle-to-Site Environmental Life Cycle Impacts of Buildings in India.

A massive amount of building construction is expected in economically developing nations such as India over the next few years. The first step in ensuring that the new construction takes place in a sustainable manner is the knowledge about the building's impact on multiple environmental domains. Life cycle assessment (LCA) is a promising tool for this, but its application in the Indian construction sector is hampered by a lack of access to detailed inventory data on amounts of all building materials used and the per unit environmental footprints of individual materials (characterization factors). Here, we overcome these limitations by proposing a novel approach that connects the building bill of quantity data with publicly available analysis of rate documents to obtain the detailed material inventory. The approach then combines the material inventory data with the newly available India-specific environmental footprint database of construction materials to calculate the impacts of a building during its different life cycle stages (cradle to site). We demonstrate the new approach through a case study of a residential building within a hospital in North-East India and quantify its environmental footprint on six domains of the environment: energy use, global warming, ozone depletion, acidification, eutrophication, and photochemical oxidant formation potential. Results show that out of 78 materials used, bricks, aluminum sections, steel bars, and cement are the major contributors to the building's total environmental impact. The material manufacturing stage is the hotspot in the building's life cycle. Our approach can act as a template for conducting "cradle-to-site" LCA of buildings for which BOQ data becomes available in India and other countries in the future.

Life cycle energy consumption, environmental impact, and costing assessment of coal to ethylene glycol processes via dimethyl oxalate and formaldehyde.

The popularization of conventional dimethyl oxalate to ethylene glycol (DMOtEG) has kept ongoing in the past decade in China. Recently, a northern China factory in construction attracts attention using alternative formaldehyde to ethylene glycol (FtEG) route. Thus, a question arises about the individual comparative advantages of these two processes. So, this paper conducts a systematic modeling analysis of DMOtEG and FtEG, and the life cycle assessment is performed by SimaPro v9 to compare their impact. The results indicate the inferiority of life cycle energy consumption and life cycle cost of FtEG to those of DMOtEG due to the high energy consumption and pollutant emissions. Moreover, most impact categories of FtEG are worse than the DMOtEG as global warming, and photochemical oxidant formation potential. Despite this, FtEG still wins for better potentials in ozone formation, fine particulate matter formation, and terrestrial acidification because of less nitride emissions. In addition, the decrease in energy consumption and external cost will significantly decrease the life cycle cost under controllable catalyst costs of FtEG. These results describe the impact categories of DMOtEG and FtEG and provide a basis to help decision-makers develop coal to ethylene glycol processes.

Regional comprehensive environmental impact assessment of renewable energy system in California

Fossil-fuel-based energy systems pose a significant threat to the climate and ecosystem. Renewable energy is considered key to achieving carbon neutrality and the Sustainable Development Goals. California is a forerunner in promoting renewable energy and sustainable development. However, regionalized renewable energy systems are accompanied by intensive material inputs and outputs, which undoubtedly have associated environmental impacts while mitigating climate change. It is necessary to measure the spatio-temporal distribution and the comprehensiveness of these impacts in order to plan renewable energy systems rationally. In this study, a life cycle assessment (LCA) on the renewable energy system of California between 2001 and 2019 was conducted to estimate the resulting diverse environmental impacts. The results show that solar energy and biomass and waste-to-energy are the main contributors to the comprehensive life-cycle impacts of the renewable energy system in California from 2001 to 2019, accounting for 62.7% ± 1.2% and 35.1% ± 1.2%, respectively. The most prominent source of environmental impact is AP, instead of the most attention-getting category, global warming potential (GWP). Geographically, Kern currently holds the highest generation of renewable energy (15.3 TWh in 2019) in the state. The corresponding normalized and weighted environmental impact is also most notable in Kern, reaching 1.7E-02 in 2019, twice as much as in Imperial, the second largest energy producing county. From 2001 to 2019, the per kWh weighted environmental impact of California's renewable energy system decreased, but the total effects increased sixfold with the promotion of renewable energy. Overall, renewable energy systems can reduce environmental impacts compared to conventional energy sources. It can help achieve some ambitious environmental goals. However, the results of this study remind us that in the renewable energy sector, we should not only focus on greenhouse gas emissions, but in the context of social development, this case shows that acidification potential (AP), ozone depletion potential (ODP) and photochemical oxidant formation potential (POFP) need to be managed more than GWP. Given the uneven distribution of natural resources, there is still room to improve further the environmentally friendly efficiency of California's renewable energy system, which will require technological advances and improved deployment of resource management.

Regional Environmental Impact Assessment of Renewable Energy System in California

Fossil-fuel based energy systems pose a great threat to the climate and ecosystem. Renewable energy is considered the key to achieve carbon neutrality and Sustainable Development Goals. California is a forerunner in promoting renewable energy and sustainable development. In this study, we conduct a life cycle assessment (LCA) on the renewable energy system of California between 2001 and 2019, assessing the abiotic resource depletion potential (ADP), global warming potential (GWP), ozone depletion potential (ODP), acidification potential (AP), photochemical oxidant formation potential (POFP), and eutrophication potential (EP), respectively . We show that solar energy and biomass and waste-to-energy were the main contributors to the overall life cycle impacts of California renewable energy system during 2001-2019, which accounted for 9.0%±1.2% and 90.7%±1.2%, respectively. Impacts on AP, POFP, EP and GWP from these two renewable sources are particularly evident. Geographically, Kern currently holds the most renewable energy generation (15.3 TWh in 2019) in the state, but Los Angeles has the highest environmental impact (1.2E-0.5 in 2019) due to a larger portion of waste-to-energy system. Renewable energy are essential for decarbonization, but the environmental impacts of certain sources, such as solar energy and waste-to-energy, demand further reduction through technology advancement and improved resource management.

Assessing suitability of commercial fibre reinforced plastic solar still for sustainable potable water production in rural India through detailed energy-exergy-economic analyses and environmental impacts

Fibre reinforced plastic (FRP) basin solar still is manufactured and marketed commercially in developing/underdeveloped nations. Unfortunately, these commercial units have not been widely adopted by the public due to its low water productivity. In the present investigation, an effort has been made to assess the performance and enviro-economic aspects of the commercial unit and its low-cost improved versions under Coimbatore climatic conditions through real-time experiments and mathematical models, respectively. The commercial unit has distillate productivity of about 2.76 L/d under cumulative solar radiation intensity of 24.37 MJ/m2d and it increased up to 6.03 L/d with the addition of black dye and thermocol insulation. Yearly average distillate production rate, thermal efficiency, and exergy efficiency of the improved version is about 4.36 L/d, 53.62%, and 6.89%, respectively. The greenhouse payback time of the commercial unit and insulated commercial unit with black dye is about 2.39 and 1.81 Years, respectively. Global warming potential, acidification potential and photochemical oxidant formation potential of the commercial unit decreased from 0.27 to 0.12 kg of carbon di-oxide eq/L of distillate, 2.40 to 1.05 g of sulphur di-oxide eq/L of distillate and 0.73 to 0.32 g of ethylene eq/L of distillate, respectively with the incorporation of low-cost improvement techniques. The sustainability index of the improved version is around 5.94% higher than the sustainability index of the commercial unit. The distillate production cost of improved version (1.32 INR/L) is closer to reverse osmosis (RO) water supplied to Indian houses (1.00 INR/L). The incorporation of low-cost improved techniques to the commercial unit makes it an attractive option for sustainable potable water production. However, proper marketing and awareness strategies must be adopted by stakeholders to make this improved version acceptable among the public.

Point Defect Model Description of the Formation of Anodic Gold Oxide in H2SO4 Solution

An impedance-based Point Defect Model (PDM) was developed for the potentiostatic, anodic formation of gold oxide at potentials of 1.40–1.70 V vs SHE in H2SO4 (0.1 M and 0.5 M). Film thickness and refractive indices were determined at each oxide formation potential using spectroscopic ellipsometry. The thickness of the oxide increases linearly with increasing potential. Mott-Schottky analysis shows that the oxide exhibits both n-type and p-type character and the dominant defect density is calculated to be in the order of 1021−1022 (1 cm−3). The PDM was optimized upon experimental EIS data to extract values for model parameters and accounts well for the experimental observations in both the steady-state time and frequency domains.

Applied properties and life cycle assessment of flexible packaging lamination processes: a comparative study

Environmental pollution is a growing problem in developing countries, including China. The packaging-printing industry is considered as one of the main contributors to air pollution in China. Film lamination represents a critical proportion of flexible packaging products. At present, traditional lamination technologies, e.g., dry lamination, consume considerable resources and generate massive pollution. Correspondingly, novel solventless lamination could effectively replace conventional lamination processes and reduce air pollution, particularly the production of volatile organic compounds (VOCs). To promote cleaner packaging and printing production in China, we applied life cycle assessment (LCA) to compare solventless and dry film lamination processes in retort pouch packaging production and further validate the environmental advantages of the solventless approach. Our research model considered the entire LCA process with an emphasis on film composite processing. E-footprint software and databases were used to assess environmental impacts based on the ISO 14040 standards. In addition, the laminated films were further assessed for peel strength based on the GB standards. Six environmental indicators, including global warming potential (GWP), photochemical oxidant formation potential (POFP), primary energy demand (PED), water use (WU), acidification potential (AP), and respiratory inorganics (RI) were selected, with a particular focus on the first two indices. The LCA results showed that the environment impact of solventless lamination was markedly smaller than that of traditional dry lamination, with critical differences reflected in power consumption and adhesive type. Compared with dry lamination, solventless lamination reduced electrical energy consumption and CO2 emissions by 74.1% and 86.37%, respectively, and the unique adhesive reducing VOC emissions by more than 94.5%. Further estimation results confirmed the above findings, indicating that solventless production can reduce VOC and pollutant emissions from sources and thus promote cleaner production. In short, solventless lamination is an effective method, both in terms of performance and environmental friendliness.

ENVIRONMENTAL IMPACTS ASSESSMENT OF BIODIESEL PRODUCTION FROM JATROPHA AND WASTE COOKING OIL (WCO)

Biodiesel that is produced from renewable resources has been rising as a promising candidate to replace conventional energy. Vietnam, with a large amount of land used in agriculture or forestry, has advantaged conditions to produce and develop renewable energy from biomass resources. However, developing biodiesel from agricultural product may affect food security significantly. Therefore, Jatropha that is inedible and waste cooking oil (WCO) could be suitable to biodiesel production. One of the most important aims of using biodiesel to replace fossil diesel is to reduce environmental impacts, particularly impact on Climate Change. It is necessary to analyze the environmental performance of biodiesel through the entire life cycle. In this paper, life cycle assessment of biodiesel production and use was applied to measure the environmental performance of biodiesel produced from jatropha oil and WCO under Vietnam conditions. Some main emissions, such as CO2, NOx, PM, CH4, VOC and land use, were computed through a cradle-to-grave analysis. The result shows that when using Jatropha biodiesel to replace diesel, global warming potential (GWP) and photochemical oxidant formation potential (POFP) could be improved, but some other impacts, such as acidification potential (AP) and eutrophication potential (EP), could tend to increase. The environmental impacts of WCO biodiesel are all reduced in comparison with fossil diesel.

Exergetic, environmental and economic sustainability assessment of stationary Molten Carbonate Fuel Cells

In this study, exergetic, environmental and economic (3E) analyses have been performed in order to provide sustainability indicators from resource extraction to the final product of stationary power Molten Carbonate Fuel Cells (MCFC) systems (500 kW). Two environmental life cycle impact assessment methods have been selected: the ReCiPe 2016 hierarchical midpoint and endpoint, and the Cumulative Exergy Extraction from the Natural Environment (CEENE). The levelized cost of electricity (LCOE) under technology cost and performance parameters was calculated to analyze the system from the economic point of view. The global warming potential (GWP) is estimated to be 0.549 kg CO2-eq/kWh while acidification (5.06e−4 kg SO2-eq/kWh), eutrophication (9.81e−4 kg P-eq. freshwater/kWh), ozone layer depletion (4.11e−6 kg CFC-11-eq/kWh) and human toxicity (1.07 kg 1,4-DB-eq/kWh). Aggregated CEENE was estimated to be about 8.55 MJex/kWh. Results show that majority of impacts are dominated by fuel supply, while some others are dominated by manufacturing of system. GWP is the only impact category dominated by system operation. Due to potentially high electrical efficiency, MCFC energy systems can lead to lower CEENE and improvements of global warming, fossil fuel and resource scarcity, and photochemical oxidant formation potential with respect to other conventional energy conversion systems. Advances in longer lifetimes of the MCFC stack can help trigger innovation in manufacturing processes and will lead to less resource use of electricity, metal, and minerals, thus less resource scarcity and toxicity related burdens. The baseline LCOE is calculated 0.1265 €/kWh being comparable with the Italian grid (0.15–0.16 €/kWh). The costing results indicate that the unit decreasing the system capital cost could potentially reduce the LCOE by around 25%. Advancing the use of life-cycle thinking in MCFC industry with site-specific data raise systems credibility and enables clarifying the trade-offs between the sustainability pillars, thus designing more sustainable products.

The effect of simulated inflammatory conditions and pH on fretting corrosion of CoCrMo alloy surfaces

Inflammation may develop due to the implantation of orthopedic devices and inflammatory cell-based chemical species may affect the fretting corrosion behavior of CoCrMo alloy. The effect of simulated inflammatory (SI) conditions and acid on the fretting corrosion behavior of CoCrMo was studied. SI conditions included phosphate buffered saline (PBS) with H2O2 and PBS with Fenton reaction (Fe3+, H2O2). Fretting corrosion behavior of CoCrMo alloy was significantly affected by both the Fenton reaction-based solution chemistry and potential. The Fenton reaction increased the oxidizing power of the solution and led to a significant rise in open circuit potential (OCP) during fretting corrosion compared to PBS and pH 3 solutions (p< 0.05). SI conditions also altered the oxide film characteristics, altering both the fretting corrosion response of CoCrMo alloy (smaller fretting currents by about 50%) and the frictional behavior compared to the PBS case. Fretting current density in Fenton reaction conditions was significantly smaller compared to PBS conditions at all potentials, indicating the oxide film was less protective due to the presence of Fenton reactions. A significantly higher coefficient of friction was observed in Fenton reaction solutions at −0.4V (0.5) and −0.6V (0.55) compared to all other conditions. This appears to be related to the oxide formation potential (−0.4V) and the effects of solution chemistry on sliding mechanics. Passivation of oxide film was the strongest in pH 3 condition, where baseline current density was the lowest at 0.6V compared to that of other solutions (p< 0.05).

Environmental life cycle assessment of seafood production: A case study of trawler catches in Tunisia

The Gulf of Gabes is one of the most productive fishery areas in the southern Mediterranean Sea. It is archetypal of an ecosystem in which the effects of fisheries are most pronounced. Demersal trawling is the main fishing activity in the Gulf of Gabes. Life Cycle Assessment (LCA) was applied to assess the environmental performance landing 1t of seafood with wooden demersal trawlers in the Gulf of Gabes. Impact categories included in the study were abiotic depletion potential (ADP), acidification potential (AP), eutrophication potential (EP), global warming potential (GWP), ozone depletion potential (ODP), photochemical oxidant formation potential (POFP), human toxicity potential (HTP), marine eco-toxicity potential (METP), terrestrial eco-toxicity potential (TETP), land occupation potential (LOP), and total cumulative energy demand (TCED). Demersal trawlers were classified based on their impact intensity. Results showed that 70% of the vessels had relatively low impacts. Impact intensity was proportional to the amount of fuel consumed to land 1t of seafood. Ships that fished less had the highest impacts per ton, due to lower fishing effort and catch per unit effort. This is likely to typify vessels that target highly valuable species such as shrimp. Onboard vessel activities contributed most to different environmental impacts (AP, EP, GWP and POFP), related to the high energy use of this fishery. Several impacts (ADP, ODP, METP, LOP and TCED) were associated mainly with fuel and lubricating oil production. Therefore, improvements must focus on minimizing fuel consumption. LCA is a valuable tool for assessing how to increase environmental sustainability of demersal trawling and it can help stakeholders identify the main operational issues that require improvement.

Enhanced corrosion resistance and surface characterization of anodized 7075 Al

In this study, we aim to enhance physical and chemical properties of 7075 aluminum via anodizing. For this purpose, convenient potential, current density, time, electrolyte type and its concentration were determined. The corrosion performances of non-anodized and anodized samples have been investigated in 3.5% NaCl by using EIS, polarization techniques. The surface morphology was determined with SEM. As a result, additive (0.5 M C2H6O2 + 0.08 M H3BO4 + 10–3 Al+3) used in 0.4 M H2SO4 was improved the quality of aluminium oxide by blocking pores, increasing the thickness and decreasing the oxide formation potential. It was achieved corrosion resistance.

Analysis of the effect of formation potential on the electrochemical response of doped titanium oxides

The electrochemical and semiconductor behavior of oxides of pure Ti and two Ti-based binary alloys, Ti99Sn1 and Ti99Cr1, were investigated using electrochemical impedance spectroscopy (EIS), Mott-Schottky analysis, intensity modulated photocurrent spectroscopy (IMPS), and potentiodynamic polarization in order to understand differences in measured oxygen reduction catalytic activity with the goal of suppressing the capability of titanium to drive galvanic corrosion. The combination of EIS techniques with IMPS was used to determine such semiconductor properties as the band gaps, flat band potentials, dielectric constants, defect concentrations, and catalytic properties, i.e., the reaction rate constants, of the oxides. The semiconductor properties of the oxides were observed to change as a function of oxide formation potential but the greatest changes in oxygen reduction rates in an alkaline solution were only found to occur with alloying, with the greatest decrease seen for the Ti99Sn1 alloy.

Electrochemical stability of carbon-supported gold nanoparticles in acidic electrolyte during cyclic voltammetry

Cyclic voltammetry has been used to assess the electrochemical stability of gold nanoparticle-based electrocatalysts with differing initial particle size distributions in sulphuric acid electrolyte. The electrochemically active surface area (EASA), based on the gold oxide reduction charge, revealed that the electrocatalyst containing gold nanoparticles with an initial number-weighted average diameter of 4.5nm was stable over 100 voltammetry cycles. Conversely, the electrocatalysts based on 3.1nm and 2.9nm gold nanoparticles showed a continuous decrease in the EASA in line with TEM and EXAFS data which confirmed growth of the gold particles during cycling. Importantly, we find no evidence to suggest that the nature of the stabilising ligand used during the gold nanoparticle synthesis, has any effect of the electrochemical stability of gold nanoparticles. When the anodic limit of the cyclic voltammograms was limited to below the gold oxide formation potential, the nanoparticles were stable, confirming that the loss in EASA is primarily related to the dissolution and growth of gold nanoparticles associated with the Au-AuOx redox process. Interestingly, an electrocatalyst initially containing 0.8nm diameter gold nanoclusters had a surprisingly low EASA (these clusters appear not to exhibit normal Au-AuOx redox behaviour typical for the larger gold nanoparticles), but still showed significant particle growth during the cycling as confirmed by TEM and XPS analysis.

Life cycle assessment of different sea cucumber (Apostichopus japonicus Selenka) farming systems

The life cycle assessment was employed to evaluate the environmental impacts of three farming systems (indoor intensive, semi-intensive and extensive systems) of sea cucumber living near Qingdao, China, which can effectively overcome the interference of inaccurate background parameters caused by the diversity of economic level and environment in different regions. Six indicators entailing global warming potential (1.86E + 04, 3.45E + 03, 2.36E + 02), eutrophication potential (6.65E + 01, −1.24E + 02, −1.65E + 02), acidification potential (1.93E + 02, 4.33E + 01, 1.30E + 00), photochemical oxidant formation potential (2.35E-01, 5.46E −02, 2.53E-03), human toxicity potential (2.47E + 00, 6.08E-01, 4.91E + 00) and energy use (3.36E + 05, 1.27E + 04, 1.48E + 03) were introduced in the current study. It was found that all environmental indicators in the indoor intensive farming system were much higher than those in semi-intensive and extensive farming systems because of the dominant role of energy input, while energy input also contributed as the leading cause factor for most of the indicators in the semi-intensive farming system. Yet in the extensive farming system, infrastructure materials played a major role. Through a comprehensive comparison of the three farming systems, it was concluded that income per unit area of indoor intensive farming system was much higher than those of semi-intensive and extensive farming systems. However, the extensive farming system was the most sustainable one. Moreover, adequate measures were proposed, respectively, to improve the environmental sustainability of each farming system in the present study.

Environmental emissions at foundation construction stage of buildings – Two case studies

Foundation construction involves heavy machine usage which contributes to greenhouse gas (GHG) and non-GHG emissions. The study aims to develop a model to estimate and compare emissions at foundation construction and demonstrate its application using two case studies. A process-based quantitative method is established to estimate emissions due to materials, transportation, and equipment usage. The results are analysed under five impact categories including Global Warming Potential, Acidification Potential, Eutrophication Potential, Photochemical Oxidant Formation Potential and Human Toxicity Potential. Analytical Hierarchy Process is employed to obtain weighting factors to assess impact categories under global and local perspectives. Results obtained an average GHG emission of 67%, 19% and 14% from materials, equipment and transportation respectively. This observation signifies the relative higher percentage of emission distribution of equipment and transportation in foundation construction compared to that in the total building construction. Considerable amount of non-GHG emissions such as Nitrous Oxides and Carbon Monoxides were recorded. Global Warming Potential remained the most prominent impact potential from all the perspectives considered, with an overpowering 75% contribution from global perspective. However, this relative importance is reduced to 33.74%–34.85%, with a relative increase in Photochemical Oxidant Formation and Eutrophication Potentials to 32.55% and 31.92% at regional and local perspective. Therefore emissions such as Nitrogen Oxides, Carbon Monoxides and Sulphur Dioxide should be given more consideration at the regional and local perspectives. Results also convey that the emission comparison perspective could change the focus of environmental impacts considerably.

Potentials for Denox in Chinese Cement Industry with the Life Cycle Assessment Method

To explore NOx mitigation strategies in Chinese cement industry systematically, a material flow analysis was developed. The realistic output of cement production in China were identified and quantified. The inventory data of Chinese cement production were selected without denitration technology applications at that time. Then the life cycle impact assessment (LCIA) results were calculated with the principal of ISO 14040 and ISO 14044 of Life Cycle Assessment. The impact categories of global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), photochemical oxidant formation potential (POCP), and human toxicity potential (HTP) were used to calculate environmental impact. The results showed that the NOx emission was the major environmental damages and the following was CO2 emission. This argument disagreed with the view that CO2 emission was the major contributor of environmental load. The reason is that the NOx emission is far over the international level due to few denitration technology applications. In the assumption of selective non-catalytic reduction (SNCR) technology applications, there is still large emission mitigation potential according to the target scenario analysis. The application of selective catalytic reduction (SCR) technology with higher deNOx efficiency and the roadmap of deNOx of Chinese cement industry were also discussed. The SNCR technology with the auxiliary of SCR development over the coming decades will be decisive for the roadmaps of Chinese cement industry to reach deeper NOx emission cuts.