Climate Change Categories Research Articles

Life Cycle Assessment of an On-Road Dynamic Charging Infrastructure

On road dynamic charging represents a possible solution for the electrification of the transport sector and eventually, for its decarbonisation. However, only a few studies have evaluated the environmental impact of this technology. A detailed life cycle assessment (LCA) of charging infrastructure is missing. This study is a life cycle assessment of the construction and maintenance of an electrified road (e-road) equipped with dynamic wireless power transfer technology (DWPT). The data from an e-road tested in a test site in Susa (Italy) have been adapted for motorway applications. The results show the relevance of wireless power transfer components compared to traditional components and materials. The wireless power transfer (WPT) component production in fact accounts for more than 70% of the impacts in the climate change category, even though it represents less than 1% weight. Maintenance is the phase with the highest impact due to the structural features of the e-road. However, there is considerable uncertainty about this value which still requires further refinement when more data from e-road monitoring are available.

Life cycle assessment of organic photovoltaic charger use in Europe: the role of product use intensity and irradiation

Solar chargers for mobile phones are the first integration of organic photovoltaic (OPV) technology into commercial products. Although environmental impacts of OPVs have been studied extensively, the performance of chargers have been narrowly examined in reference to intensity of their use and use geographies. To explore these aspects, we study the environmental impacts of OPV chargers considering the charger as a substitute for a local electricity grid supply for charging a mobile phone. A consequential life-cycle assessment (LCA) was carried out to evaluate the environmental performance of the OPV charger in six European countries representative of different electricity grids and solar irradiation contexts. Particular effort is made to explore the implications of use intensity of the charger and determine a frequency at which charger is competitive. The results suggest that using an OPV charger has the potential to be environmentally friendly only in countries with high fossil-fuel share in their electricity supplies. The OPV charger is environmentally beneficial in Greece and Spain across most of the evaluated impact categories if used 100–120 times per year, which is practical given the high solar insulation in the two countries. Charging a phone with OPV in Germany or the Netherlands is environmentally-friendly only under conditions of intensive use of the device, or for selective impact categories. In the category of climate change, charging with OPV would represent an improvement in Greece and Germany. In two countries a phone-charging supported by OPV generates 2.5 kg of CO2-equivalents per year in comparison to 2.9–3 kg CO2-equivalents charging from the grid. Phone-charging supported by OPV in Norway and France is more impactful than using the grid for the majority of impact categories, including the category of climate change. The study contributes a novel methodology for looking at photovoltaic technology and helps inform users and policymakers who should consider the local context before an adoption of environmental technologies.

Life Cycle Assessment of Recycling Processes for Demolition Waste

This contribution is aimed to evaluate the environmental impacts of recycling construction and demolition waste with the use of Life Cycle Assessment. In the first step, the LCA was used as an analytical tool for the comparison of recycled aggregates production. Recycled aggregates were produced from brick and concrete waste. Chosen functional unit for the comparison was 1 ton of recycled aggregate (RA). The results show that concrete aggregate production has a higher impact on Climate Change category (1,51 kg CO2 eq.) than brick aggregate production (1,18 kg CO2 eq.). Then, in the second step, new concrete mixtures made of recycled aggregates were compared. Functional unit was 1 m3 of concrete. Environmental impacts of concrete mixtures were compared with reference concrete mixture. These compared concretes are classified as C20/25 according to CSN EN 206 + A1. Mixtures with concrete RA have a higher environmental impact than mixtures which were made of brick RA. GaBi Software ts for data processing was used. Environmental impacts assessment according to the ReCiPe method characterization, version 1.08 was used.

Life-Cycle Assessment of Adsorbents for Biohydrogen Production

Adsorbents are used to remove impurities such as carbon monoxide, carbon dioxide, methane, and hydrogen sulfide in the pressure swing adsorption process of biohydrogen production. These impurities are present in the produced gas along with hydrogen and often cause voltage reduction in fuel cells and shorten the lifespan of catalysts. Zeolite A is a typical adsorbent, and more recently, hydroxyl aluminum silicate clay (Has-Clay) and Kanuma clay have been suggested as alternatives. We conducted a life-cycle assessment (LCA) of zeolite A, Has-Clay, and Kanuma clay, and evaluated their environmental impact based on the ReCiPe midpoint method. Kanuma clay had the least impact in all of the environmental categories. The largest contributions for zeolite A and Has-Clay were in the categories of climate change and fossil depletion. In the climate change category, production of 1 kg of Has-Clay and zeolite A was estimated to emit 17.142 kg CO2 eq and 2.352 kg CO2 eq, respectively. In the fossil depletion category, the values were estimated to be 3.999 kg oil eq and 1.039 kg oil eq, respectively. These LCA results will be useful in designing and using adsorbents in pressure swing adsorption processes to meet environmental challenges associated with sustainable biohydrogen production.

Evaluation and comparison of environmental performance for shackle insulators – a case study

Purpose The purpose of this paper is to compare environmental performance of two shackle insulator manufacturing enterprises in India by evaluating and quantifying the life cycle environmental impacts in these enterprises using ISO 14040 guidelines. Design/methodology/approach All relevant life cycle phases – raw material, manufacturing, transportation and disposal – are considered. Primary inventory data for the two enterprises are collected through observations of processes at the sites. Ecoinvent 3.0 database is used as secondary data source. Process flow models are developed using Umberto software. ReCiPe impact assessment methodology is adopted to calculate environmental impacts in terms of endpoint categories of ecosystem quality, human health and resource availability; and midpoint categories of climate change, fossil depletion, human toxicity, metal depletion, ozone depletion, terrestrial acidification and water depletion. Findings This study has found that manufacturing phase followed by raw material extraction and transportation phases are responsible for most of the environmental impacts. This study also found that raw materials used in glaze preparation (manganese and ferrite), electricity, heavy fuel oil (C-9) and cotton have high environmental impacts in the manufacturing phase. Research limitations/implications The limitation of this study is that most of the inventory data are collected from only two manufacturing plants. Practical implications The researchers/enterprises can use the knowledge body for modelling and result comparison under different conditions. The enterprises can do the micro analysis of environmental effects of processes to improve environmental as well as economic performance. The government agencies can use the data for policy development and deployment. Originality/value The main contribution of the research is the creation of a knowledge body in the area of ceramic product environmental impacts. The paper provides inventory for the life cycle assessment (LCA) of shackle insulators using primary source (measured values) as no secondary data source is available for the shackle insulators. The inventory and results of this study can be used as reference for the future LCA studies in ceramic industry.

Strategies for reducing the environmental impacts of organic mozzarella cheese production

This study first investigates the environmental performance of 1 kg organic mozzarella cheese production, performing a cradle-to-gate attributional life cycle assessment. The upstream process related to organic milk production contributed the most to the impact category of climate change in the cheese's life cycle. Electricity and water consumption were the main contributors to impacts at the dairy plant level. Then, disregarding the impacts from milk, five scenarios related to technological and management strategies at plant level are proposed, including a new equipment acquisition, changes in the production volume rate, and the use of byproducts to obtain new foods. The use of a cooling tower during milk pasteurization reduced water consumption by 60%. Varying the production volume of the dairy beverage resulted in relevant changes in all impact categories considered. Differences in the volume of mozzarella cheese production did not result in relevant changes in the impact categories. The use of skimmed buffalo milk proved to be a feasible option to produce the Minas frescal light cheese. Also, an inventory of mozzarella cheese certified as organic was obtained. Such results can provide more reliable information to stakeholders regarding product choice and processes with the best environmental performance for the dairy industry.

Sustainability analysis of innovative technologies for the rare earth elements recovery

The rare earth elements (REEs) were classified as critical raw materials for Europe for their economic relevance and the supply risk. Currently, most of REE production is concentrated in the Chinese area and it is used for the production of many technologies including: fluorescent lamps, fluid catalytic cracking catalysts and permanent magnets. At the end of their life, these products can cause management problems, mainly due to the hazardous component presence. Nevertheless, this critical issue is combined with the significant content of REEs, which makes them a potential resource of secondary raw materials. In this regard, the literature reports many processes for the waste exploitation, but the effective sustainability is often neglected. In this context, the present paper took into account three processes, one for each mentioned waste, to assess both the environmental and the economic aspects. The obtained results were allocated on the basis of metals market price proving an advantage for most of the elements, compared to the primary production. Following the paper evaluation, the fulfillment of the circular economy approach could reduce up to 200 times the impact in the climate change category and up to 70 times the cost due to the REE mining.

Szarvasi-1 and Its Potential to Become a Substitute for Maize Which Is Grown for the Purposes of Biogas Plants in the Czech Republic

The domestic biogas market has been developing rapidly, and legislation (The Act) supporting the use of renewable energy sources has come into force. In light of this act and investment support from national programs co-financed by the European Union (EU), the total number of biogas plants has recently increased from a few to 600. The total capacity of electricity generation of those 600 installed plants exceeds 360 Megawatts (MW) (as of mid-2018). Such dynamic growth is expected to continue, and the targets of the National Renewable Energy Action Plan are projected to be met. The use of waste material, which was urgently needed, was the original aim of biogas plants. However, in certain cases, the original purpose has transformed, and phytomass is very often derived from purpose-grown energy crops. Maize is the most common and widely grown energy crop in the Czech Republic. Nevertheless, maize production raises several environmental issues. One way to potentially reduce maize’s harmful effects is to replace it with other suitable crops. Perennial energy crops, for example, are possible alternatives to maize. A newly introduced species for the conditions of the Czech Republic, Elymus elongatus subsp. ponticus cv. Szarvasi-1, and some other well-known species—Phalaris arundinacea L. and Miscanthus × giganteus—are suitable for Czech Republic climate conditions. This paper presents the findings of the research and evaluation of environmental, energy-related, and economic aspects of growing these crops for use in biogas plants. These findings are based on 5-year small-plot field trials. The energy-related aspects of producing Elymus elongatus subsp. ponticus cv. Szarvasi-1, Phalaris arundinacea L., and Miscanthus x giganteus are reported on the basis of experiments that included measuring the real methane yield from a production unit. The economic analysis is based on a model of every single growing and technological operation and costs. The environmental burden of the individual growing methods was assessed with a simplified life cycle assessment (LCA) using the impact category of Climate Change and the SimaPro 8.5.2.0 software tool, including an integrated method called ReCiPe. The research findings show that Szarvasi-1 produces 5.7–6.7 Euros (EUR) per Gigajoule (GJ) of energy, depending on the growing technology used. Szarvasi-1 generates an average energy profit of 101.4 GJ ha−1, which is half of that produced by maize (214.1 GJ ha−1). The environmental burden per energy unit of maize amounts to 16 kg of carbon dioxide eq GJ−1 compared with the environmental burden per energy unit of Szarvasi-1, which amounts to 7.2–15.6 kg of CO2 eq GJ−1, depending on the yield rate. On the basis of the above-mentioned yield rate of Szarvasi-1, it cannot be definitively recommended for the purpose of biogas plants in the Czech Republic.

Transforming rooftops into productive urban spaces in the Mediterranean. An LCA comparison of agri-urban production and photovoltaic energy generation

A key strategy towards sustainable urban development is designing cities for increased circular metabolism. The transformation of areas underused, such as urban rooftops, into productive spaces is being increasingly implemented as a result of associated multiple benefits. Rooftop greenhouses (RTGs) are an interesting option for exploiting urban rooftops with direct exposure to sunlight, reducing food miles and creating new agricultural spaces, while building-applied solar photovoltaic (BAPV) panels provide clean energy and reduce greenhouse gas emissions. However, a proper assessment of environmental costs and benefits related to both systems is vital for a successful implementation. By means of Life Cycle Assessment (LCA) method, modelled in the professional software SimaPro, this paper aims at comparing the environmental performance of different productive uses of rooftops under Mediterranean climatic conditions. The results showed that both systems are favourable and contribute to decreasing the environmental impacts thanks to the production of resources on-site. BAPV system shows the highest avoided burdens in comparison with RTG: for instance, the impacts generated by BAPV on climate change and fossil depletion categories, corresponding to - 430 kg CO2 eq/m2 and - 110 kg oil eq/m2 respectively (versus - 22 kg CO2 eq/m2 and - 4.7 kg oil eq/m2 in the RTG system), are around 20 times lower than RTG. Furthermore, a sensitivity analysis was performed through different scenarios, based on reductions or substitution of the most sensitive input flows, thus providing some useful tools for improved environmental performances. Attention to additional energy and material efficiency, in favour of the more environmentally sustainable choice, should remain a main point of investigation.

Dynamic impact assessment of resource depletion: A case study of natural gas in New Zealand

The depletion of abiotic resources is a critical issue for the present as well as future generations. Resource depletion is governed by several factors including resource costs and elasticity of demand, which are dynamic. In this paper, a dynamic resource depletion methodology is proposed that is based on the assessment of impacts to the wider community. The methodology is demonstrated for a case study of natural gas scarcity in New Zealand. A system dynamics model predicts the gas price and the natural gas consumption rate over an extended period. The potential environmental impacts are assessed using life cycle assessment (LCA), coupled with the resource substitution methodology. The impacts are further aggregated into a resource depletion indicator based on environmental economics and decision-making perspectives for the environment. For some gas-consuming sectors, consumption is reduced, but for other sectors other fuels are substituted for the natural gas such as black coal and imported liquefied natural gas (LNG). For the New Zealand case study, the substitution delays the exhaustion of the domestic natural gas supply, at the cost of higher environmental impacts. The substitution of gas with black coal caused an increase in the environmental impact indicator in the climate change category by 36%, 63% and 104% for the individualist, hierarchist and egalitarian approaches, respectively. Similarly, the substitution of gas by imported LNG resulted in an increase in the same category by 7%, 17% and 33% for the individualist, hierarchist and egalitarian perspectives, respectively. The difference in indicator results under each perspective shows that the impacts associated with resource depletion changes with time, which is ignored by the traditional LCA. The impacts-related information that is obtained from the new indicator would be useful in decision-making during situations in which there maybe resource and energy scarcity.

An Environmental Evaluation of the Cut-Flower Supply Chain (Dendranthema grandiflora) Through a Life Cycle Assessment

Colombia is a major flower exporter of a wide variety of species, among which the chrysanthemum plays a major role due to its exporting volume and profitability on the international market. This study examines the major environmental impacts of the chrysanthemum supply chain through a life cycle assessment (LCA). One kg of stems export quality was used as the functional unit (FU). The study examines cut-flowers systems from raw material extraction to final product commercialization for two markets (London and Miami) and analyzes two agroecosystems: one certified system and one uncertified system. The transport phase to London resulted in more significant environmental impacts than the transport phase to Miami, and climate change (GWP100) category was significant in both cities, generating values of 9.10E+00 and 2.51E+00 kg CO2-eq*FU for London and Miami, respectively. Furthermore, when exclusively considering pre-export phases, the uncertified system was found to have a greater impact than the certified system with respect to fertilizer use (certified 1,448E-02 kg*FU, uncertified 2.23E-01 kg*FU) and pesticide use (certified 1.24 E-04 kg*FU, uncertified 2.24E-03 kg*FU). With respect to the crop management, eutrophication (EP) and acidification (AP) processes imposed the greatest level of environmental impact. Strategies that would significantly reduce the environmental impact of this supply chain are considered, including the use of shipping and a 50% reduction in fertilizer use.

A Life Cycle Assessment of Two Residential Buildings Using Two Different LCA Database-Software Combinations: Recognizing Uniformities and Inconsistencies

Traditionally, the emissions embodied in construction materials have not been considered important; however, they are becoming crucial due to the short time-frame in which the emissions should be reduced. Moreover, evaluating the environmental burden of construction materials has proven problematic and the reliability of the reported impact estimates is questionable. More reliable information from the construction sector is thus urgently needed to back and guide decision-making. Currently, the building sector environmental impact assessments predominantly employ commercial software with environmental impact databases and report results without knowledge about the impact of the software/database choice on the results. In this study, estimates for the embodied environmental impacts of residential construction from the two most widely used life cycle assessment (LCA) database-software combinations, ecoinvent with SimaPro software and GaBi, are compared to recognize the uniformities and inconsistencies. The impacts caused by two residential buildings of different types, a concrete-element multi-story residential building and a detached wooden house, both located in Finland, were assessed, including all building systems with a high level of detail. Based on the ReCiPe Midpoint method, fifteen impact categories were estimated and compared. The results confirm that the tool choice significantly affects the outcome. For the whole building, the difference is significant, around 15%, even in the most widely assessed category of Climate Change, and yields results that lean in different directions for the two cases. In the others, the estimates are entirely different, 40% or more in the majority of the categories and up to several thousand percentages of difference. The main conclusion is that extensive work is still urgently needed to improve the reliability of LCA tools in the building sector in order to provide reliable and trustworthy information for policy-making.

Removing Shadows from Consequential LCA through a Time-Dependent Modeling Approach: Policy-Making in the Road Pavement Sector.

Lack of dynamic accounting in consequential life cycle assessment (CLCA) can keep policy-makers from having an accurate analysis of emission flows over time. In this study, we propose a dynamic CLCA framework to assess the environmental consequences of pavements. Dynamic changes in the demand vector and technosphere matrices were computed using relevant time horizons of affected supply technologies and incorporating time-dependent parameters. A Monte Carlo simulation was then conducted to propagate the variability, model uncertainty, and parameter uncertainty sources of LCI to the damage results. The results show that simplifying pavement CLCA framework through neglecting real-time changes results in notable diversions in the damage results. The environmental benefits of substituting asphalt with concrete are underestimated by 7, 17, and 77% for climate change, human health and resources categories, respectively. A divergence of 114% was also observed in ecosystem quality when using the static framework. Moreover, the lack of accounting for a temporal profile for GHG emissions using static characterization factors leads to a divergence of the GWP benefits of substituting asphalt with concrete of 473 t CO2eq (105%). The uncertainty results show 41-71% contribution of the variance in the damage categories is caused by the variability sources and is primarily attributed to monthly temperature accounting and service life.

Life cycle analysis of copper-gold-lead-silver-zinc beneficiation process

Gold, silver, lead, zinc, and copper are valuable non-ferrous metals that paved the way for modern civilisation. However, the environmental impacts from their beneficiation stage was always overlooked. This paper analysed the life cycle environmental impacts from the beneficiation process of gold-silver-lead-zinc-copper combined production. The analysis is conducted by utilising the SimaPro software version 8.5. The life cycle assessment methodologies followed are the International Reference Life Cycle Data System (ILCD) method, the IMPACT 2002+ method, and the Cumulative Energy Demand Method (CED). The most significant impact categories are ecotoxicity, climate change, human toxicity, eutrophication, acidification, and ozone depletion among nearly 15 impact categories which are assessed in this study. The analysis results from the ILCD method indicate that there is a noteworthy impact on ionising radiation caused by the beneficiation process. Out of the five metals considered, gold and silver beneficiation impacts the most while lead‑zinc beneficiation impacts the least. Gold beneficiation has most impacts on the category of climate change and ecosystems. Other major impact categories are ionising radiation, terrestrial eutrophication, photochemical ozone formation, human toxicity, and acidification. The IMPACT 2002+ method shows the overall impact is on ecosystem quality and human health from this combined beneficiation process, dominantly from gold‑silver beneficiation. The life-cycle inventory results show that the blasting process and the amount of electricity consumption in the beneficiation process contribute to cause significant amount of environmental impacts. The comparative impact results are presented and discussed in detail in this paper. Sensitivity analyses are presented based on various electricity grid-mix scenarios and energy-mix scenarios, and the results suggest that electricity grid mix has a dominant effect over the fossil-fuel mix. This paper also highlights the potential steps which could cut down the environmental effects by integrating renewable-energy technologies.

Case study of life cycle assessment in bread production process

Technological advances sometimes bring negative effects, for example, there are emissions of gas and waste as a result of manufacturing activities. The research was carried out at the bread manufacturing with the intent calculate Life Cycle Inventory and Impact Assessment using life cycle analysis framework in ISO 14040. The stages of this research are from a preliminary study which contains goal definition and scope, followed by literature study, field survey and interview for data acquisition - inventory definition. The final stage is the analysis and conclusion that contains the impact analysis and interpretation of the impact. The impact measured up to the final process of bread making is the packaging stage using the 2002+ impact method. The results are there is the potential human health of 9.39E-05 DALY, ecosystem quality 42 PDF*m2*yr, climate change 118 kg CO2 eq and resources 247 MJ Primary. The comparison of baking, injection, and packaging process, it is found that there was a slight increase in damage category of human health and climate change, while no change in ecosystem quality. It is found in the study that the most dominant factor that contributes to environmental impact is the use of electricity.

On the relevance of scope 3 emissions and power trade for regional life cycle inventories of electricity consumption in the USA

Most life cycle inventories (LCIs) of electricity consumed in different regions of the USA disregard the power that is being traded between these regions, while the US EPA’s eGRID database does not contain scope 3 or noncombustion emissions. The relevance of these omissions has not yet been comprehensively quantified in the literature. This paper aims to close this knowledge gap. The parameterized inventory models that underlie all publicly available grid mix datasets in the GaBi databases were configured to create 26 eGRID subregional LCIs based on data from EPA’s eGRID2014 database and the Federal Energy Regulatory Commission’s FERC-714 report on power trade for the same reference year. Results were calculated regarding climate change, acidification, eutrophication, particulate matter, smog formation, and blue water consumption per kilowatt hour of electricity and compared for direct plant emissions only, the cradle-to-gate production mix (including scope 3), and the cradle-to-gate consumption mix (including scope 3 and power imports). Results showed that the scope 3 burdens represent the most significant data gap if not accounted for. Specifically, the GWP results show median increases of around + 18% for GWP100 and of + 30% for GWP20 when scope 3 GHG emissions are added to the direct plant emissions. Other impact categories showed even larger increases when compared to direct plant emissions, with a maximum increase of + 573% in eutrophication potential for the subregion CAMX. While the median deviations of the consumption mixes compared to the production mixes are moderate, individual subregions show significant increases in environmental burdens for selected metrics. However, power trade seems less of an issue for the impact category of climate change as only the CAMX subregion shows an increase larger than 10% when power trade is accounted for. A cradle-to-gate production mix can be a suitable proxy of the environmental burdens of electricity consumed in many subregions, but it can also lead to significant errors for others depending on the environmental metric(s) one is trying to assess. Power plant emissions by themselves (scope 2) that exclude both scope 3 emissions and power trade cannot be recommended for use in any kind of carbon accounting or other environmental analysis because they suffer from severe data gaps and may skew the comparison of the environmental burdens associated with power consumption in the different subregions significantly.

Life cycle assessment of common carp (Cyprinus carpio L.) – A comparison of the environmental impacts of conventional and organic carp aquaculture in Germany

The steadily growing aquaculture industry has been blamed for increasing environmental impacts at local and global levels. The greatest increase in production is expected for freshwater fish, such as carp and related species. Decisions on sustainable environmental management strategies in aquaculture should be based on quantitative analyses of their environmental impacts.In this study, Life Cycle Assessment (LCA) methodology was employed to compare the environmental impacts of conventional and organic common carp (Cyprinus carpio L.) raised in traditional pond aquaculture. Data collected in personal interviews with carp farmers in southern Germany was used for inventory analysis. Interviews with farmers showed that in practice, the key difference between organic and conventional production of carp lies in the sourcing of feed grains from certified organic versus conventional origin.The results of the impact analysis showed that conventional carp production has higher indicator values for climate change, ozone depletion as well as ionizing radiation (human health) and uses more water resources. Organic production led to higher acidification and an increase of over 100% in marine and terrestrial eutrophication compared to conventional production. Independent of the production system, feed and pond dredging (i.e., the effort of sludge removal from the pond using machinery) were the main contributors to many of the impact categories, apart from freshwater eutrophication, which was largely dependent on the carp farming stage. Therefore, the environmental superiority of one production method over the other depends on the impact category analyzed. A comparison with previously published LCAs of fish and meat products for the impact category of climate change shows that both, conventional and organic carp, have significantly lower indicator values than products from recirculating aquaculture systems or terrestrial animal products, such as beef. This finding, as well as the retention functions and ecosystem services provided by carp ponds, contribute to the environmental sustainability of both forms of carp aquaculture studied.Further efforts to increase the systems' sustainability should target the key areas of feed type and amount, frequency and method of pond dredging as well as the nutrient retention rate of carp, affecting potential emissions during harvest. Moreover, carp products with organic certification, wanting to uphold their claim of superior environmental friendliness, should address the critical issues uncovered in this LCA. Continuing methodological development, which acknowledges aquaculture specific impacts, will further increase the applicability of LCAs for products from aquaculture.

Environmental benefit of utilizing bamboo material based on life cycle assessment

This study focuses on the production chains that produce plybamboo for use. The production chains were investigated using a life cycle assessment (LCA) approach, which takes into account all of the input and output flows occurring along the production chain. The results show that the major processing type of plybamboo production is mechanical processing. The characterization of various materials demonstrates that bleached glue-laminated bamboo boards exert the greatest potential environmental impact in terms of power consumption during the three-layer lamination process; in particular, the category with the highest environmental impact is respiratory inorganics. Therefore, energy consumption and productivity are the key factors of the potential environmental impact. The comparison of the two treatment types revealed that the bleached glue-laminated bamboo boards have a lower environmental impact in all four categories than their heat-treated counterparts. The impact of the processing mainly originates from the steps of hot pressing, drying and using chemicals. The comparative results show that plybamboo has a low environmental impact, but the impact is higher than that of concrete. Concerning the carbon storage of plybamboo, using plybamboo has environmental benefits in the impact categories of climate change and global warming. Although plybamboo has a low impact in the impact categories of climate change and global warming, it has a high impact in other impact categories. Therefore, policy makers should consider the highest impact of the aforementioned processing steps and should use energy-saving and high productivity equipment to reduce the environmental impact.

Environmental assessment of vacuum and non-vacuum techniques for the fabrication of Cu2ZnSnS4 thin film photovoltaic cells

Cu2ZnSnS4 (CZTS) is one of the most promising alternatives for photovoltaic (PV) applications, since it is made from earth abundant and low toxicity materials. To assess the potential of CZTS PV cells in the future global market, it is useful to investigate the sustainability by assessing the possible environmental impacts of large-scale production. Life cycle assessment (LCA) of CZTS absorber layers fabricated by vacuum and non-vacuum deposition techniques has been studied using information from laboratory-scale processes as well as large scale estimations. Copper indium gallium diselenide (CIGS) was selected as a reference vacuum-based process. The paper compares the environmental impacts of the vacuum and non-vacuum processes by considering the three main damage categories of climate change, human health and eco-toxicity using Sima Pro software. The results show that the CZTS films fabricated with both deposition techniques exhibit a significant potential benefit over the CIGS thin films. The toxicity to human health was found to depend critically on the compounds and components selected for preparing the precursors. The energy consumption for processing the CZTS thin films via the non-vacuum deposition technique is considerably less than that required for the other techniques.

Environmental Quantification of the Existing Waste Management System in a Developing World Municipality Using EaseTech: The Case of Bahawalpur, Pakistan

Evaluation of existing operational and managerial provisions and identification of specific actions that fit and impact in a local context is key to find sustainable solutions. The study aims to develop an understanding of existing waste management practices for a medium sized city of Pakistan and to quantify the related environmental impacts using life cycle assessment (LCA). The existing waste management system in “Bahawalpur”, a city with predominant rural-urban infusion, is characterized by straining resources, low generation rates (0.424 kg/capita/day), prominent source separation, high scavenging activities and open dumping practices. The waste composition analysis proposes organic wastes as the largest constituent (64%) followed by recyclables (27%) and inerts (9%). The LCA model “EaseTech” used to quantify the environmental performance of existing waste management arrangements illustrated that existing waste management system in Bahawalpur City has tangible effects on climate change (3.16 × 107 kg CO2-Eq) and ecotoxicity (3.12 × 106 CTU) categories, while depletion of abiotic resources fossil (−9.60 × 107) category points up most environmental savings. Significant environmental compensations for different impact categories are offered due to high source separation and recycling trade off. The overview necessitates suitable modification in existing waste disposal practice that poses severe impacts on the environment.