Freshwater Aquatic Ecotoxicity Research Articles

Comparative life cycle analysis between commercial porcelain stoneware and new ones designed by using volcanic scraps

To achieve carbon neutrality by 2050, many companies have started implementing sustainability policies. The aim of this work, as result of collaboration between Universities and companies, is to assess the environmental impacts associated with the production of alternative formulations of porcelain stoneware. The proposed formulations contain extraction scraps and chamotte and have promising technological properties. A comparative analysis of the life cycle in three different scenarios was carried out to assess the environmental footprint of the final products. The analyzed scenarios were a glazed porcelain stoneware (which was taken as a reference and is commercially available), a porcelain stoneware containing pumice scraps, and one containing volcanic lapillus scraps. It was observed that the transportation of raw materials has the largest environmental impact, followed by the production and extraction of the raw materials themselves. From the performed analysis, it was possible to observe that by replacing the currently used materials by the ones hereby studied, environmental benefits can be obtained. In particular, depending on the considered pollutant, the environmental impact can be reduced between a minimum of about 8 % (Freshwater Aquatic Ecotoxicity category) to a maximum of 48 % (Acidification category). In a time when raw materials supply is difficult, the use of scraps, which would otherwise be disposed of, is particularly interesting and can lead to the production of an environmentally friendly product.

Life Cycle Assessment as a Decision-Making Tool for Photochemical Treatment of Iprodione Fungicide from Wastewater

Water contamination with various micropollutants is a serious environmental concern since this group of chemicals cannot always be removed efficiently with advanced treatment methods. Therefore, alternative chemical- and energy-intensive oxidation processes have been proposed for the removal of refractory and/or toxic chemicals. However, similar treatment performances might result in different environmental impacts. Environmental impacts can be determined by adopting a life cycle assessment methodology. In this context, lab-scale experimental data related to 100% iprodione (a hydantoin fungicide/nematicide selected as the model micropollutant at a concentration of 2 mg/L) removal from simulated tertiary treated urban wastewater (dissolved organic carbon content = 10 mg/L) with UV-C-activated persulfate treatment were studied in terms of environmental impacts generated during photochemical treatment through the application of a life cycle assessment procedure. Standard guidelines were followed in this procedure. Iprodione removal was achieved at varying persulfate concentrations and UV-C doses; however, an “optimum” treatment condition (0.03 mM persulfate, 0.5 W/L UV-C) was experimentally established for kinetically acceptable, 100% iprodione removal in distilled water and adopted to treat iprodione in simulated tertiary treated wastewater (total dissolved organic carbon of iprodione + tertiary wastewater = 11.2 mg/L). The study findings indicated that energy input was the major contributor to all the environmental impact categories, namely global warming, abiotic depletion (fossil and elements), acidification, eutrophication, freshwater aquatic ecotoxicity, human toxicity, ozone depletion, photochemical ozone creation, and terrestrial ecotoxicity potentials. According to the life cycle assessment results, a concentration of 21.42 mg/L persulfate and an electrical energy input of 1.787 kWh/m3 (Wh/L) UV-C light yielded the lowest undesired environmental impacts among the examined photochemical treatment conditions.

Critical reviews and benchmarking Tunisian clinker and cement with life cycle assessment results

Clinker and cement production is an energy-intensive and high resource requirement industry with significant environmental impacts, and yet, there is a dearth of environmental research in Tunisia on its Life Cycle Assessment (LCA). Additionally, there is a tendency either to overlook or underestimate the selection of appropriate life cycle impact assessment methods. This study aims to address these issues by conducting a comprehensive LCA of Tunisian cement production with the goal of analyzing and comparing the results using various methods and benchmarking against existing literature. Three different Life Cycle Impact Assessment (LCIA) methods, including IMPACT 2002+, CML (baseline), and ReCiPe Midpoint (2008–2016) (H), were used. These methods were chosen for their different coverage (regional/global) of their impact categories, leading to a more comprehensive comparison of the performance of clinker and cement to the literature. In addition, the similarity with published values demonstrates reliability for LCA results, except ionizing radiation, ozone layer depletion, and respiratory organics in IMPACT 2002+ for clinker, CEM-I, and CEM-II; fresh water aquatic ecotoxicity and marine aquatic ecotoxicity in CML (baseline) for CEM-I; and photochemical oxidant formation: ecosystem quality and human health in ReCiPe for CEM-I. This low variability with the reported values in the literature suggests the capability of using the benchmarking approach as a proxy in a context of lack of data.

Negative net global warming potential hydrogen production through biomass gasification combined with chemical looping: Environmental and economic assessments

The integration of biomass gasification (BG) with chemical looping hydrogen production (CLHP) offers one prospective approach for green hydrogen production. The environmental and economic assessments are conducted to evaluated the sustainable performance of the BG-CLHP system during the hydrogen production cycle (HPC). The results showed that the environmental impacts of BG-CLHP are concentrated in freshwater aquatic ecotoxicity (FAETP), human toxicity (HTP), and acidification (AP). The BG-CLHP system can provide a more cost-competitive hydrogen supply solution for hydrogen refueling stations compared the offshore wind or photovoltaic (PV) powered electrolysis, given the same hydrogen production target. For global warming potential (GWP) and cost, the BG-CLHP demonstrates excellent integrated performance with GWP values of −15.13 and −17.00 kg CO2, eq/kg H2, for the Air case and Oxygen case, and the costs of 3.05 and 2.82 $/kg H2, respectively, and sensitivity analysis reveals that the CLHP stage is the primary contributor to GWP. Compared with existing hydrogen production routes, BG-CLHP can still be improved in terms of costs and the technical maturity, however, the excellent negative GWP properties of BG-CLHP make it will play a more important role in future large-scale hydrogen production.

Evaluating the carbon footprint of sulphur recovery unit: A comprehensive analysis

Desulphurising of oil based fuels and industrial gases is a widespread practice. The combustion process in the sulphur recovery unit (SRU) involves the reaction of H2S with oxygen to produce SO2, which is then converted to elemental sulphur through a series of catalytic reactions. Oxygen enrichment is a technique used to enhance the performance and efficiency of the SRU. By introducing a higher concentration of oxygen into the combustion process, the overall combustion reaction can be optimised, resulting in an increased sulphur recovery from sour gas and reduced emissions of sulphur compounds. The present study analyses the gate-to-gate comparative environmental impact of air versus oxygen enriched air used for combustion to recover 1.0 ton sulphur using GaBi software (8.5.0.79 version). The primary data was collected from the literature. The GaBi Indian extension database is used for the secondary data source. The results are reported using midpoint impact assessment methods CML 2001. The global warming potential for oxygen-enriched SRU is 232 kg CO2 eq. compared to 276 kg CO2 eq. for air enriched SRU. Similarly, the potential for abiotic depletion (elements + fossil), acidification, eutrophication, human toxicity, freshwater aquatic ecotoxicity, marine aquatic ecotoxicity, photochemical ozone creation and terrestric ecotoxicity are higher for air based SRU than oxygen-enriched SRU. The analysis concludes that oxygen enrichment technology is a highly effective way to reduce the environmental impact of the SRU.

Environmental sustainability assessment of softwood and hardwood seedlings production in forest nurseries: A case study from Pakistan.

This article describes the environmental impacts of producing a single seedling in forest nurseries of selected districts (i.e., Haripur, Abbottabad, and Mansehra) of Hazara Division of Khyber Pakhtunkhwa, Pakistan using the life cycle assessment (LCA) approach. This study was based on the cradle-to-gate approach which begins with the pre-nursery stage and progresses toward the main nursery before transplanting seedlings into the plantation site. Data or life cycle inventory (LCI) of seedling production were collected through questionnaire surveys and personal meetings with forest nurseries managers and workers regarding consumption of different inputs such as electricity, diesel, fertilizers, herbicides, and polyethylene bags, organic manure, and water consumption. The SimaPro software version 8.5 and the CML2000 v2.05 environmental model was applied to perform life cycle impact assessment (LCIA) for a single seedling production in forest nurseries in the study area. In line with the objectives of the study, primary data regarding inputs and outputs of the nurseries were collected from 35 nurseries in the study area by using a random questionnaire method. In addition, secondary data were taken from online databases such as Eco-invent v.3.2 CORRIM and peer-reviewed published literature. For this study, a functional unit of a single seedling was considered. Production weighted average data were modeled in the latest environmental modeling software i.e., SimaPro v.8.5 for ten US-EPA most wanted environmental impacts, such as global warming potential (GWP), abiotic depletion (AD), eutrophication potential (EP), acidification potential (AP), freshwater aquatic eco-toxicity (FAE), marine water eco-toxicity (MWE), terrestrial eco-toxicity (TE), ozone layer depletion (OLD), photochemical oxidation (PO), and human toxicity (HT). The results showed that the highest environmental impact posed by a single seedling was marine aquatic eco-toxicity (11.31360 kg 1,4-DB eq), followed by global warming potential (0.02945 kg CO2 eq) and (0.01227 kg 1,4-DB eq) human toxicity. The primary reason for these environmental burdens was the use of synthetic fertilizers in forest nurseries and the consumption of fossil fuels in nursery mechanization and transportation activities. The total cumulative energy demand for a single seedling was (0.800 MJ) with more than 90% contribution from fossil fuel energy resources such as petrol and diesel. It is therefore highly recommended to use renewable energy resources and organic fertilizers instead of chemical fertilizers in forest nurseries to avoid and minimize greenhouse gas emissions (GHS) and other toxic emissions in the study area.

Comparative Life Cycle Assessment (LCA) of two tofu industries that uses different energy sources for production processes

Tofu industry is engaged in processing food made from soybeans, which has a significant contribution to emissions. Padang City has 12 tofu industries, including the ‘A’ tofu industry and ‘B’ tofu industry. The ‘A’ tofu industry and ‘B’ tofu industry produce 990 kg and 2,400 kg of tofu/day, respectively. The difference between them is the application of briquettes and diesel fuel in ‘A’ tofu industry, while ‘B’ tofu industry uses firewood and electricity for boiling and milling processes. Therefore, this study purpose to analyze the environmental impact of 1 kg of tofu using the Life Cycle Assessment method with SimaPro ver.9.0. A gate-to-gate approach was used. The result of the characterization impact on the environment is ‘B’ tofu industry had the highest impact than ‘A’ tofu industry, marine aquatic ecotoxicity 645.69 and 419.91 kg1.4-DBeq, human toxicity 39.81 and 0.33 kg1.4-DBeq, global warming potential 36.96 and 16.68 kgCO2eq, abiotic depletion 15.02 and 13.27 MJ, fresh water aquatic ecotoxicity 2 kg1.4-DBeq and acidification 0.01 and 0.0075 kgSO2eq. A component that contributes to harmed the environment is the boiling process. From the result, several alternatives can be recommended, replacing fuel for the boiling process with briquettes and treating liquid waste with an aerobic-anaerobic-biofilter.

Developing a carbon footprint model and environmental impact analysis of municipal solid waste transportation: A case study of Tehran, Iran

ABSTRACT The greenhouse gas emitted due to transportation is the third greatest emitter globally, and its impact has become a threat to the environment, public health, and economic development. Waste transportation is excluded in studies of waste management despite its significant environmental impacts such as global warming and human toxicity. The objective of this study is to develop a quantification model to estimate the carbon footprint of waste transportation and environmental impact assessments in three categories applied in Tehran using IPCC guidelines. In Tehran, light and heavy vehicles ran on diesel fuel. Data on fuel and waste characteristics were provided by Tehran’s department of transportation and municipality, respectively. In this study, transport-related emissions are 8.47 k tonCO2eq/y, and the carbon footprint of waste transportation is 93.57 g of CO2 eq per ton of waste transported (t.km), which is relevant to three main parameters: the amount of waste transported annually, the freight shipped from the temporary station to the disposal landfill site, and fossil fuels consumed. Also, an environmental impact assessment in three categories – human health (global warming, abiotic depletion, and ozone layer depletion), resources (fossil fuels), and ecosystem quality (acidification and eutrophication) – using SimaPro, a Life Cycle Assessment (LCA) tool is presented. Global warming (3.49 kg CO2 eq/t MSW), human toxicity (0.95 kg 1,4-DB eq/t MSW), and freshwater aquatic eco-toxicity (0.04 kg 1,4-DB eq/t MSW) have the greatest impact among categories. Sensitivity analysis of the effective parameters allows us to conclude one of the potential implications of this study would be the introduction of natural gas or biogas-based trucks replacing diesel fuel vehicles to improve air quality and mitigate the greenhouse gas emission. Implications: This paper addresses the significant issue of global warming, particularly in Iran, a developing country that ranks among the top contributors to greenhouse gas emissions. The study emphasizes the importance of evaluating emissions across various sectors such as electricity, waste, etc., Specifically, in this paper we focus on developing a model to quantify the environmental impact resulting from the combustion of fossil fuels in vehicles, focus on the metropolitan city of Tehran as a case study. By examining the waste transportation process, we aim to provide decision-makers with effective strategies to mitigate the environmental consequences. In this paper, we develop a simple quantification term of Carbon Footprint to calculate total greenhouse gas emission of waste transportation process. Carbon Footprint is a fraction which, its numerator is total greenhouse gas emission and its denominator is total waste transported in traveled distance. Effective parameters have been investigated and based on parameters and emission factors taken out of IPPC, the carbon footprint model have been developed. The total greenhouse gas emission of this study and the carbon footprint has estimated at 8.47 k tonCO2eq/y and 93.57 g CO2eq/t.km respectively. Furthermore, the paper explores additional environmental impacts beyond global warming, including abiotic depletion, ozone layer depletion, acidification, eutrophication, human toxicity, photochemical oxidation, and freshwater aquatic eco-toxicity. Using SimaPro software these eight impact categories have been estimated. in this study we identify fossil fuel consumption, traveled distance, and mass transported are the primary parameters influencing greenhouse gas emissions and the carbon footprint. To reduce emissions in the waste transportation system, we suggest promoting renewable biofuels, highlighting Iran as a suitable candidate due to its high percentage of biodegradable material in municipal solid waste. Additionally, the study assesses nonrenewable energy and mineral extraction using the IMPACT 2002+ V2.15/IMPACT 2002+ method, revealing that global warming (100 years), human toxicity (100 years), freshwater aquatic eco-toxicity, nonrenewable energy, and mineral extraction have the most significant impacts on the municipal solid waste transportation system. Overall, this research underscores the need for quantifying environmental impacts and recommends strategies to mitigate them in waste transportation processes, particularly in developing countries like Iran.

A holistic life cycle design approach to enhance the sustainability of concrete structures

AbstractThe development of innovative cementitious materials such as Ultra High Performance Concrete (UHPC) requires tailored approaches to assess both the environmental and economic impact of structural applications employing them. For this purpose, in this paper, Life Cycle Assessment (LCA) and Life Cycle Cost (LCC) methodologies are integrated into a Durability Assessment‐Based Design (DAD) workflow which combines structural design algorithms for UHPC with the assessment of the durability performance, with the aim of predicting the evolution of the structural performance all along the service life (SL) in the intended scenarios. As a case study a water tank made of UHPC has been herein selected and compared to a reference made of ordinary reinforced concrete (ORC). While the ORC solution was designed with cantilever cast in situ walls, two different design concepts were assessed for the UHPC basin: one with cast in situ walls and one with precast slabs supported by ORC columns. Moreover, two different mix designs (mainly differing on the alternative presence of silica fume or slag) have been investigated for the UHPC basin and a SL equal to 50 years has been taken into account for each structure. The optimized design, together with the reduced frequency of the maintenance activities for the UHPC structure, allowed by the UHPC superior material and structural durability, resulted into consistent reductions of environmental impacts, up to 76% as for Human Toxicity and Fresh Water Aquatic Ecotoxicity in comparison to the ORC solution. In addition to this, an assessment of the overall construction and maintenance costs that occur during the lifetime of the structures showed a cost reduction higher than 40% for both UHPC solutions, mainly due to a reduction of up to 6% during the construction phase and 91% for the maintenance activities. This also highlights the importance of the correct metrics in evaluating the sustainability of UHPC structural applications, which has to move forward from the units volume or mass of material and its individual constituents to functional units, representative of the benefits of using advanced cement based materials in structurally and environmentally challenging service scenarios.

Life cycle engineering (LCE) study for Synechococcus HS-9 biomass production as potential raw material for a third generation biodiesel production

The LCE study aims to reduce the environmental impact of the biomass production of Synechococcus HS-9. It is the main feedstock in producing biodiesel as a potential alternative fuel from using Indonesia’s natural resources. The LCE study shows that the use of electricity and compressors contributed the highest to the environmental impact. Synechococcus HS-9 dry biomass production process affects the environment of 8.38x10-9Pt. The five significant impacts include Marine Aquatic Ecotoxicity Pot. (MAETP), Human Toxicity Potential (HTP inf.), Freshwater Aquatic Ecotoxicity Pot. (FAETP), Abiotic Depletion (ADP elements) and Global Warming Potential (GWP). The LCE design solution significantly reduces environmental impact by scenario changing electrical energy from State Electricity Company (PLN) using coal to electricity from renewable energy sources. On the other design solution, the best generation compressor scenario (new technology) can reduce the environmental impact by an average of 20% compared to the average generation compressor (current technology). The average GWP value is generated successively from the use of renewable energy, namely municipal waste energy at 7%, hydropower energy at 10%, onshore wind power at 7.05%, geothermal energy at 12.08%, PV at 13.84%, and natural gas at 50% of GWP value generated by the PLN electricity source using coal.

Megacity's pathway toward sustainable food waste management and its environmental performance in a developing country: Evidence from Shanghai, China

Due to the far distance impact on resident, aquatic and soil ecosystem health, food waste disposal becomes the focus of municipal waste strategy in developing countries. Shanghai is a leading city in China, its evolution of food waste management can indicate the coming future of the nation. In this city, from 1986 to 2020, the open dumping, landfill and incineration of food waste had been gradually banned, replaced by centralized compost and anaerobic digestion and other recovery ways. This study selected ten scenarios, ever used for food/mixed waste disposal in Shanghai, and analyzed the environmental impact change during the period 1986–2020. Life cycle assessment showed that although the generation of food waste raised rapidly, the total environmental impact, which was dominated by Freshwater Aquatic Ecotoxicity Potential, displayed a sharp decrease as 96.09 %, and Global Warming Potential decreased by 28.14 %. Substantial efforts should be made to improve the collection rate of biogas and landfill gas to reduce environmental impact, and quality of residues from anaerobic digestion and compost plants should be improved and utilized in its legal ways. Driving forces for the goal of sustainable food waste management in Shanghai involved economic development, environmental regulations and the supporting national/local standards.

Environmental impact study on conversion of multilayer metallized packaging to paving blocks with a Life Cycle Assessment (LCA) approach

Plastic waste management in Indonesia is relatively poorly implemented due to the limited number of recyclers. One of the most abundant plastic wastes is multilayer metallized plastic packaging (MLP). This study was conducted to analyze the environmental impacts of MLP and plastic bag waste conversion to paving blocks (PVB) with a life cycle assessment approach and aimed to determine whether such a process brings positive or negative impacts to the surrounding environment. The assessment was performed gate-to-gate on input data, including raw materials, energy, support materials, and output, using openLCA 1.11 software, ecoinvent 3.8 databases, and CML-IA baseline method. Secondary data on waste plastic treatment in a sanitary landfill was inferred from the database for comparative analysis. Environmental impacts arising from the production of 1 PVB (20 × 10 × 6 cm, 700 g) are acidification 0.00913 kg SO2 eq, eutrophication 0.00243 kg PO4 eq, freshwater aquatic ecotoxicity 0.8391 kg 1,4-DB eq, global warming (GWP100a) 2.68006 kg CO2 eq, human toxicity 1.2672 kg 1,4-DB eq, and terrestrial toxicity 0.00247 kg 1,4-DB eq. Compared to treatment in a sanitary landfill, conversion of MLP lowered eutrophication and freshwater aquatic ecotoxicity to the environment, whilst other impacts are higher due to energy input in the processes. Conversion of MLP to PVB is proposed as an alternative to plastic waste management.

Analysis of the life cycle environmental impact reductions of remanufactured turbochargers

Recently, remanufacturing approach/technology, which includes a series of the processes of disassembling, cleaning, inspecting, repairing/reconditioning, reassembling components for resale, is becoming more popular as companies look for a way to combat the current climate crisis, and as it allows companies to reduce environmental impacts and to save energy and resources. This study analyzed the reduction effect of six environmental impacts and the savings effect of energy and resources by turbocharger remanufacturing compared to its newly manufacturing using a life cycle assessment (LCA) methodology. The results show that the most significant benefit of the turbocharger remanufacturing related to environmental impacts was the global warming potential (GWP), which could be reduced by 52.2%, followed by the abiotic depletion potential (ADP), terrestrial ecotoxicity potential (TETP), human toxicity potential (HTP), freshwater aquatic ecotoxicity potential (FAETP) and marine aquatic ecotoxicity potential (MAETP) which could be reduced by 51.9%, 44.8%, 44.2%, 42.6%, and 36.7%, respectively. Also, its resource saving could be obtained from 21.7 to 73.5% depending on the type of resources. Furthermore, turbocharger remanufacturing offered a significant energy saving of 83.9%. The results obtained from this study could be used for national policy-making to a net-zero carbon transition.

Identification of recycling pathways for secondary aluminum dross with integrated hybrid life cycle assessment

The development of secondary aluminum dross (SAD) has become a hot topic to deal with aluminum resource scarcity and landfill risk as hazardous waste. This study first compares the environmental impact, resource consumption, and economic performance of four emerging SAD reutilization methods with an integrated hybrid life cycle assessment (IHLCA). The results show that IHLCA captures larger environmental and economic impacts than process LCA (PLCA), especially for midpoint indicators, such as human toxicity potential, acidification potential, freshwater aquatic ecotoxicity. Furthermore, multi-component recovery from SAD is not always the best choice. The multi-component recovery scenario of SAD-to-alumina with alkali has the smallest environmental impact and resource consumption, while SAD-to-PAC with acid is the worst due to the massive use of HCl. Particularly, SAD-to-calcium aluminate with single-component recovery stands out due to its best economic performance. The given results provide new perspective on making a sustainable decision for SAD recovery industrialization.

Life cycle assessment of high concentration organic wastewater treatment by catalytic wet air oxidation

There have been many studies on life cycle assessment in sewage treatment, but there are scarce few studies on the treatment of industrial wastewater in combination with advanced oxidation technology, especially in catalytic wet air oxidation (CWAO). There are no cases of using actual industrialized data onto life cycle assessment. This paper uses Simapro 9.0 software to establish a life cycle assessment model for the treatment of high-concentration organic wastewater by CWAO, and comprehensively explains the impact on the environment from three aspects: the construction phase, the operation phase and the demolition phase. In addition, sensitivity analysis and uncertainty analysis were performed. The results showed that the key factors affecting the environment were marine ecotoxicity, mineral resource consumption and global warming, the operation stage had the greatest impact on the environment, which was related to high power consumption during operation and emissions from the treatment process. Sensitivity analysis showed that electricity consumption has the greatest impact on abiotic depletion and freshwater aquatic ecotoxicity, and it also proved that global warming is mainly caused by pollutant emissions during operation phase. Monte Carlo simulations found slightly higher uncertainty for abiotic depletion and toxicity-related impact categories.

Life cycle assessment of Moringa oleifera derived biodiesel: Energy efficiency, CO2 intensity and environmental impacts

AbstractThis paper performs a thorough cradle to tank life cycle assessment to examine environmental impacts of Moringa oleifera derived biodiesel. Attributional LCA according to ISO 14040‐44, using CML‐IA baseline method, was conducted. Furthermore, Biodiesel versus petrodiesel comparison was undertaken.Moringa oleifera derived biodiesel shows a GWP of 39.94 gCO2eq/MJ of biodiesel, which presents a reduction of 52.34%, compared to petrodiesel. It revealed an EROEI value of 1.48, which can reach 3.20 with allocation applying, presenting an energy saving over petrodiesel of 53%. In addition, Ozone layer depletion impact of Moringa based biodiesel is lower than that of petrodiesel. This good performance notwithstanding, Moringa oleifera derived biodiesel exhibits high environmental impacts in terms of Abiotic Depletion of elements, Human Toxicity, Fresh water aquatic ecotoxicity, Marine aquatic ecotoxicity, Terrestrial ecotoxicity, Acidification, Eutrophication, respectively, 96.60%, 60.22%, 82.13%, 64.77%, 98.71%, 35.68% and 76.70% higher than those of petrodiesel. Nevertheless, coproducts valorization and ecofriendly inputs use could contribute efficiently to improve its environmental performances compared to petrodiesel.According to our results and comparison with other feedstocks based biodiesel, Moringa biodiesel could be used as a sustainable biofuel with a high contribution to climate change mitigation and fossil energy savings in addition to reduced environmental impacts.

A Life Cycle Assessment of the Combined Utilization of Biomass Waste-Derived Hydrochar as a Carbon Source and Soil Remediation

The conversion of waste biomass to hydrochar by hydrothermal carbonation (HTC) treatment is a promising technology for waste management, and the thorough utilization of hydrochar can reduce the environmental load. Herein, a life cycle assessment (LCA) was performed to evaluate hydrochar as a carbon source in wastewater plants (WWTPs) and subsequently soil remediation. The simulated combined utilization of hydrochar showed that Bacillus subtilis may utilize the dissolved organic matter (DOM) of hydrochar that contains many aliphatic organic substances, and the microbially treated hydrochar retains most of the nutrients for crop growth. LCA shows that hydrochar could avoid 28% of the environmental load of WWTPs in terms of global warming (GWP100) and 47% of the environmental load of freshwater aquatic ecotoxicity and could reduce 54% of the environmental impact of soil fertilization in terms of eutrophication and 34% of GWP100 in soil remediation. Furthermore, LCA results indicate that hydrochar derived at 160 °C has the lowest environmental load in the combined utilization. This study proposes an optimized utilization of biomass wastes and extends the life cycle of derived hydrochar by experimental determination and the LCA method.

Comparative life cycle assessment of first‐ and second‐generation bio‐isobutene as a drop‐in substitute for fossil isobutene

AbstractIsobutene (IBN, C4H8) is widely used in industry. Currently, IBN production relies on petrochemical processes. The current work assesses the comparative environmental sustainability of bio‐based IBN production routes based on first‐ and second‐generation sugar compared with fossil IBN by applying the ISO 14044‐based Life Cycle Assessment methodology. In total nine scenarios are examined. Scenarios 1–6 used first‐generation sugar for IBN fermentation and scenarios 7–9 use cereal straw‐based second‐generation sugar. The scenarios also differ in their process energy source. The savings in Global Warming Potential for first‐generation IBN are up to 68% (scenario 1); for second‐generation IBN, the savings reach 105% if an avoided burden approach for utilizing lignin as an energy source is applied (scenario 8). It is found that applying renewable process energy is a prerequisite to maximizing greenhouse gas savings. Special attention has to be drawn to the eutrophication potential, were none of the scenarios show savings. This is driven by sugar crop cultivation owing to fertilizer usage, thermal energy from solid biomass or natural gas due to NOx emissions and nutrient use for fermentation (e.g. ammonia). Scenarios 4, 7 and 8 show savings in the acidification potential compared with fossil IBN. A driver of acidification is biomass‐based process energy generation, mainly due to SO2 and NOx emissions from biomass combustion. In contrast, all scenarios show a better environmental performance concerning the freshwater aquatic ecotoxicity potential, the abiotic depletion and the photochemical ozone creation potential. Process development should focus on conversion efficiencies and a fully renewable process energy supply. © 2022 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.

Life cycle environmental sustainability and cumulative energy assessment of biomass pellets biofuel derived from agroforest residues.

This study was carried out to produce low-emitting biomass pellets biofuel from selected forest trees such as (Cedrus deodara and Pinus wallichiana) and agricultural crop residues such as (Zea mays and Triticum aestivum) in Gilgit-Baltistan, Pakistan using indigenously developed technology called pelletizer machine. Characterization, environmental life cycle impact assessment, and cumulative energy demand of biomass pellets biofuel produced from selected agriculture crops and forest tree residues were conducted. The primary data for biomass pellets production was collected by visiting various wood processing factories, sawmills, and agricultural crop fields in the study area. Biomass pellets are a type of biofuel that is often made by compressing sawdust and crushing biomass material into a powdery form. The particles are agglomerated as the raw material is extensively compressed and pelletized. Biomass pellets have lower moisture content, often less than 12%. Physically, the produced pellets were characterized to determine moisture content, pellet dimensions, bulk density, higher heating value, ash content, lower heating value, and element analysis. A functional unit of one kilogram (kg) biomass pellets production was followed in this study.The life cycle impact assessment of one kg biomass pellets biofuel produced from selected agro-forest species revealed environmental impact categories such as acidification (0.006 kg SO2 eq/kg pellets), abiotic depletion (0.018 kg Sb eq/kg pellets), marine aquatic ecotoxicity (417.803 kg 1,4-DB eq/kg pellets), human toxicity (1.107 kg 1,4-DB eq/kg pellets), freshwater aquatic ecotoxicity (0.191 kg 1,4-DB eq/kg pellets), eutrophication (0.001 kg PO4 eq/kg pellets), global warming (0.802 kg CO2 eq/kg pellets), and terrestrial ecotoxicity (0.008 kg 1,4-DB eq/kg pellets). Fossil fuel consumption was the hotspot source to all environmental impacts investigated. To measure the cumulative energy demand of biomass pellets made from different agroforestry species leftovers showed that the maximum cumulative energy was from wheat straw pellets (13.737 MJ), followed by corncob pellets (11.754 MJ), deodar sawdust pellets (10.905 MJ) and blue pine sawdust pellets (10.877 MJ). Among the various production activities, collection and transportation of primary raw material, crushing, screening, adding adhesives, pelletizing, cooling, final screening, and packing have the maximum contribution to the water scarcity index, followed by lubricating oil (0.00147m3). In contrast, the minimum contribution to water footprint was from electricity (0.00008m3) and wheat starch (0.00005m3). The highest contribution to the ecological footprint impact categories such as carbon dioxide, nuclear, and land occupation was lubricating oil and less contribution of wheat starch and electricity for manufacturing one kg pellets biofuel. It is concluded that physico-mechanical and combustion properties of the biomass pellets biofuel developed in the present study were following the Italian recommended standards. Therefore, it is strongly recommended that the Government of Pakistan should introduce the renewable biomass pellets industry in the country to reduce dependency on fossil fuels for cooking and heating purposes.

Greenhouse gas reduction strategies for building materials: A reality check with the climate targets

The increasing importance of the embodied emissions in the life cycle of buildings has led to a growing interest in strategies supporting their mitigation. In this paper are presented the environmental impacts of 10 variants of a single-family house assessed with the life cycle assessment (LCA) method. A set of potential technological improvements and strategies are applied at the material level. Their influence at the building level is discussed and the resulting global warming potentials are compared to the COP21 targets for Austrian buildings. Finally, potential trade-offs in 9 other environmental impact categories are explored. The results show that, when incorporating all of the assessed strategies for emission reduction, the embodied greenhouse gas (GHG) emissions could be reduced up to 87% at the material level and 50% at the building level. Carbon capture and storage and the use of bio-based materials are to be credited for the highest share of these reductions. However, there is no version of this building that fulfils the COP21 targets. Other pathways, which do not solely rely on material-related technological improvements, should be investigated. A more radical change of the building industry might even be necessary. Overall, the implementation of the strategies decreased the environmental impacts in almost every impact category, except for freshwater aquatic ecotoxicity.