Carbon Footprint and Sensitive Design Parameters of Residential and Industrial (Whey) Wastewater Treatment Plants: A Comparative Life Cycle Assessment (LCA)

The production of cellulase enzymes (CE) has been identified as one major contributor towards the life cycle environmental and economic impacts of second-generation lignocellulosic bioethanol (LCB) production. Despite this knowledge, the literature lacks consistent and transparent life cycle assessments (LCA) which compare CE production based on the three more commonly proposed carbon sources: cornstarch glucose, sugar cane molasses and pre-treated softwood. Furthermore, numerous LCAs of LCB omit CE production from their system boundaries, with several authors citing the lack of available production data. In this article, we perform a comparative attributional LCA for the on-site production of 1 kg CE in full broth via submerged aerobic fermentation (SmF) based on the three alternative carbon sources, cases A, B and C, respectively. We determine life cycle inventory (LCI) material consumption using stoichiometric equations and volume flow, supplemented with information from the literature. All LCIs are provided in a consistent and transparent manner, filling the existing data gaps towards performing representative LCAs of LCB production with on-site CE production. Life cycle impact assessment (LCIA) results are determined with SimaPro 8 software using CML 1A baseline and non-baseline methods along with cumulative energy demand and are compared to results of similar studies. Sensitivity analysis is performed both for all major assumptions and for market changes with the application of advanced attributional LCA (AALCA). We find that CE production from pre-treated softwood (case C) provides the lowest environmental impacts, followed by sugar cane molasses (case B) and then cornstarch glucose (case A), with global warming potentials of 7.9, 9.1 and 10.6 kg CO2 eq./kg enzyme, respectively. These findings compare well with those of similar studies, though great variation exists in the literature. Through sensitivity analysis, we determine that results are sensitive to assumptions made concerning carbon source origin, applied allocation, market changes, process efficiency and electricity supply. Furthermore, we find that the contribution of CE production towards the overall life cycle impacts of LCB is significant and that the omission of this sub-process in LCAs of LCB production can compromise their representativeness.

Cotton yarns spun from natural fibers are widely used in the apparel industry. Most of waste cotton goods are now disposed by incineration or landfill, which brings resource and environmental challenges to the society. Using the waste cotton to spin yarns is an alternative way to forward a more sustainable future. In this research, two scenarios for the environmental impacts of yarns spun from corresponding fibers are investigated, including recycled cotton fibers and virgin cotton fibers. The life cycle assessment (LCA) has been conducted according to the collected data from on-site investigation of typical production factories. The life cycle for the recycled cotton yarn production is divided into five stages, i.e., raw material acquisition, transportation, breaking, mixing, and spinning. The life cycle of virgin cotton yarn production is been divided into four stages, i.e., raw material acquisition, transportation, mixing, and spinning. The functional unit is 1000 kg produced yarns which are used for weaving into the fabrics. Notable impacts on climate change, fossil depletion, water depletion, and human toxicity were observed. The life cycle impact assessment (LCIA) results show that environmental impacts of recycled cotton yarns are far less than those of virgin cotton yarns, except for climate change and water depletion. The reason is that the land occupation and irrigation water have great impact on environmental impacts of cotton cultivation. In spinning, the electricity is the key factor whose environmental impacts account for the most in the virgin cotton yarn scenario, while the electricity and water consumptions are the key factors for the recycled cotton yarn scenario in the life cycle of yarn production. The sensitivity analysis indicates that improving energy efficiency can significantly reduce environmental burdens for both the two scenarios. The uncertainty distribution of water depletion, human toxicity, fossil depletion, and climate change of the two scenarios were determined with a 90% confidence interval. The LCIA results reveal recycled cotton yarn is a viable alternative to relieve resource and environmental pressure. About 0.5 ha of agricultural land can be saved, 6600 kg CO2 eq can be reduced, and 2783 m3 irrigation water can be saved by using 1000 kg of the recycled cotton yarns. It can be concluded that the recycled cotton fibers can be served as a substitute for virgin cotton fibers to reduce agricultural land and avoid environmental impacts generated from the cotton planting.

A life cycle assessment (LCA) of feminine hygiene products was completed with three samples considered representative of sanitary pads, tampons and menstrual cups. Gabi LCA software was used to organize inventory data with the ILCD (v.1.0.10) life cycle impact assessment method used to determine mid-point and normalized impact scores. Data from the ecoinvent database, and literature were used to complete the assessment. The dataset includes product details (mass and materials), life cycle inventory (LCI) data and life cycle impact assessment (LCIA) results for all mass and energy flows. Hait and Powers [1] used the data in a comparative LCA.

PurposeNowadays, hydroponic cultivation represents a widely used agricultural methodology. The purpose of this paper is to study comparatively on hydroponic substrates. This study is highlighting the best substrate to be involved in hydroponic systems, considering its costs and its sustainability.Design/methodology/approachSeven substrates were evaluated: rock wool, perlite, vermiculite, peat, coconut fibres, bark and sand. Life cycle assessment (life cycle inventory, life cycle impact assessment (LCIA) and life cycle costing (LCC)) was applied to evaluate the environmental and economic impact. Through the results of the impacts, the carbon footprint of each substrate was calculated.FindingsPerlite is the most impacting substrate, as highlighted by LCIA, followed by rock wool and vermiculite. The most sustainable ones, instead, are sand and bark. Sand has the lower carbon footprint (0.0121 kg CO2 eq.); instead, bark carbon footprint results in one of the highest (1.1197 kg CO2 eq.), while in the total impact analysis this substrate seems to be highly sustainable. Also for perlite the two results are in disagreement: it has a high total impact but very low carbon footprint (0.0209 kg CO2 eq.) compared to the other substrates. From the LCC analysis it appears that peat is the most expensive substrate (€6.67/1,000 cm3), while sand is the cheaper one (€0.26/1,000 cm3).Originality/valueThe LCA and carbon footprint methodologies were applied to a growing agriculture practice. This study has highlighted the economic and environmental sustainability of seven substrates examined. This analysis has shown that sand can be the best substrate to be involved in hydroponic systems by considering its costs and its sustainability.

Binders are important construction materials, especially with plant-based granulates and fibers. A binder is chosen for its physical and chemical properties to be compatible with some construction requirements. New market trends show that green binders meet global sustainability targets, which is a step towards greener buildings and a greener environment. This study presents a cradle-to-gate comparative life cycle assessment (LCA) of synthetic binders (Polyvinyl Acetate (PVA) and Carboxymethyl Cellulose (CMC)) and agriculture starch-based binders made from cassava, wheat, and corn. The LCA was conducted using SimaPro software based on ISO 14040/14044 standards using the ReCiPe Midpoint and CML IA Baseline method. The assessment is cradle-to-gate with a binder production function unit of 1 kg. Key environmental sustainability metrics like Global Warming Potential (GWP) and Acidification Potential (AP) are assessed to rank the binder sustainability against each other. The results show that synthetic binder PVA has the highest environmental impact in almost all impact categories, especially GWP (6.55 kg CO2 eq in ReCiPe and 6.37 kg CO2 eq in CML) and AP (0.012 kg SO2 eq in ReCiPe and 0.015 kg SO2 eq in CML). Among natural binders, Corn Starch shows the lowest environmental impact with GWP values of 0.930 kg CO2 eq (ReCiPe) and 0.896 kg CO2 eq (CML) and AP values of 0.010 kg SO2 eq (ReCiPe) and 0.016 kg SO2 eq (CML). The agricultural binders (Cassava Starch, Wheat Starch, and Corn Starch) are environmentally friendlier than the synthetic binders (PVA and CMC). Although agricultural binders carry environmental costs associated with farming operations, they have lower environmental impacts than synthetic alternatives, demonstrating their sustainability potential in binder applications.

Microplastics and heavy metals emissions from healthcare waste management: A comparative life cycle assessment.

A cradle-to-gate life cycle assessment for clean hydrogen gas production pathway using the CeO2/Ce2O3-based redox thermochemical cycle

Binders play a critical role in the construction industry, especially when combined with plant-based granulates and fibers. The binder is selected based on its physical and chemical characteristics for compatibility with certain construction requirements. New market trends highlight the use of green binders that meet global sustainability targets, demonstrating a move toward greener building and environmental sustainability. This study presents a cradle-to-gate comparative life cycle assessment (LCA) of synthetic binders – namely Polyvinyl Acetate (PVA) and Carboxymethyl Cellulose (CMC) and agriculture starch-based binders made from cassava, wheat, and corn. The Life Cycle Assessment was conducted using SimaPro software based on ISO 14040/14044 standards using the ReCiPe Midpoint and CML IA Baseline. The assessment is cradle-to-gate with a function unit of 1 kg for binder production. Key environmental sustainability metrics such as Global Warming Potential (GWP) and Acidification Potential (AP) are assessed to rank the binder sustainability relative to each other. The results show that synthetic binder PVA has the highest environmental impact in almost all impact categories, especially GWP (6.55 kg CO2 eq in ReCiPe and 6.37 kg CO2 eq in CML) and AP (0.012 kg SO2 eq in ReCiPe and 0.015 kg SO2 eq in CML). Among natural binders, Corn Starch shows the lowest environmental impact with GWP values of 0.930 kg CO2 eq (ReCiPe) and 0.896 kg CO2 eq (CML) and AP values of 0.010 kg SO2 eq (ReCiPe) and 0.016 kg SO2 eq (CML). The agricultural binders (Cassava Starch, Wheat Starch, and Corn Starch) are environmentally friendlier than the synthetic binders (PVA and CMC). Although agricultural binders carry environmental costs associated with farming operations, they have lower environmental impacts than synthetic alternatives, demonstrating their sustainability potential in binder applications.

In the mitigation policy, agricultural activities are gaining growing importance. International and national regulations require the use of sustainable production methods. This means that the attention focused on the current recommendations shifts from a set of minimum requirements to recognize environmental effects throughout the life cycle of products. Farming and food production are also expected to comply with the second pillar of sustainability which is related to the economic aspects of production. Important operational dimension of sustainability assessment is a concept of eco-efficiency, which is defined as creating more value or generating less cost with less environmental impact. Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) are appropriate methodologies to investigate the eco-efficiency of production systems within the life cycle. The aim of the study was to perform the comparative analysis of cash crop production in different farming types by applying the LCA and LCC methods. Carbon Footprint (CF) was applied as a single most important measure of environmental impact of production. The study was conducted in 69 farms, located in the Wielkopolska and Lubelskie regions (Poland) during the period 2017-2018. The analysed farms represented key agricultural activities, according to the classification of the EU: a) milk production, b) pig production, c) field crops, d) mixed livestock production (pig and milk). The chosen types of production are represented by the largest number of farms in Poland. The selection of the study group, according to the set criteria, were based on the information of Wielkopolski and Lubelski Agricultural Advisory Centres. The LCA and LCC analysis were carried out in similar phases corresponding to LCA standard: goal and scope definition, environmental life cycle inventory, life cycle impact assessment and interpretation. In winter rape production average value of CF was equal to 1003 kg CO2 eq per 1 tonne of grain (functional unit). The highest value of CF was observed in milk farming in Wielkopolska region of 1254 kg CO2 eq. Average aggregated cost of production related to the functional unit was 1084 PLN, with the highest value of 1222 PLN found in the pig farming in Lubelski region. Preproduction phases linked with the direct inputs levels contributed mostly to a high overall cost of rape production in pig farming and to the CF value of winter rape in farms specialised in milk production. *This work is a part of a research project No. 2016/21/B/HS4/01963 financed by the National Science Centre, Poland.

The main purpose of this study is to quantify and compare the embodied carbon (EC) from the materials used or designed to build the Adohi Hall, a residence building located on the University of Arkansas campus in Fayetteville, AR. It has been constructed as a mass timber structure. It is compared to the same building design with a steel frame for this study. Based on the defined goal and scope of the project, all materials used in the building structure are compared for their global warming potential (GWP) impact by applying a life cycle assessment (LCA) using a cradle-to-construction site system boundary. This comparative building LCA comprises the product stage (including raw material extraction, processing, transporting, and manufacturing) plus transportation to the construction site (nodule A1–A4, according to standard EN 15804 definitions). In this study, GWP is primarily assessed with the exclusion of other environmental factors. Tally®, as one of the most popular LCA tools for buildings, is used in this comparative LCA analysis. In this study, the substitution of mass timber for a steel structure with a corrugated steel deck and concrete topping offers a promising opportunity to understand the GWP impact of each structure. Mass timber structures exhibit superior environmental attributes considering the carbon dioxide equivalent (CO2 eq). Emissions per square meter of gross floor area for mass timber stand at 198 kg, in stark contrast to the 243 kg CO2 eq recorded for steel structures. This means the mass timber building achieved a 19% reduction in carbon emissions compared to the functional equivalent steel structure within the building modules A1 to A4 studied. When considering carbon storage, about 2757 tonnes of CO2 eq are stored in the mass timber building, presenting further benefits of carbon emission delays for the life span of the structure. The substitution benefit from this construction case was studied through the displacement factor (DF) quantification following the standard process. A 0.28 DF was obtained when using mass timber over steel in the structure. This study provides insights into making more environmentally efficient decisions in buildings and helps in the move forward to reduce greenhouse gas (GHG) emissions and address GWP mitigation.

The production of oil and natural gas is the main source of economic activity and a vital component of the global energy system. However, a major contributor to greenhouse gas emissions that directly cause anthropogenic climate change is the production process. This study looks at the effects of oil and gas production in Indonesia's Ujung Pangkah field on the environment, specifically on global warming potential (GWP) fossil fuels, along the whole supply chain, from the extraction of raw materials to the products' transit (distribution). Life cycle assessment (LCA) in accordance with ISO 14040:2016, ISO 14044:2017, and the Product Category Rules (PCR) of Crude Petroleum and Natural Gas Version 1.0 2023-06-19 is the methodology used in this study. The software SimaPro 9.1.0.8 was used to do the life cycle impact assessment. Cradle to grave is the system boundary established for this study, encompassing both direct emissions from operations and indirect emissions from energy use. According to the paper's conclusion, the characterisation results for oil, gas, and LPG's Global Warming Potential (IPCC 2021 GWP100 VI.02) are 0,06910 kg CO2 eq, 0,07494 kg CO₂ eq, and 0.7786 kg CO2 eq, respectively. The results also show that, during the course of the product's life cycle, the core stream phase as a utility—specifically, the unit processes of diesel generator & emergency WHP-A and diesel generator & emergency WPN—contributes the most to the environmental impact. This is because pertadex diesel is used as fuel for the power in the living quarters and offshore (WHP-A) in WPN. Diesel consumed in diesel electric producing is the parameter of the Pertadex (Ecoinvent database)

This study aims at dynamic behaviour of a Linke Hofmann Busch coach and its sensitive parameters against track irregularities considering various suspended equipment. The randomly distributed track irregularities characterized in terms of Indian Rail Road PSD standard are considered main source of excitation that produces undesired vibrations. The coach body and bogie frame subjected to 4 degree of freedom motions (bounce, lateral, roll and pitch) are modelled using finite element methodology where system matrices such as mass, stiffness and damping matrices are obtained for eigenvalue solution. Using modal parameters obtained as above and PSD of track irregularities, both vertical and lateral mean square acceleration responses (MSAR) are determined at various points of concern on coach body. It is observed that the vertical peak responses occur in low frequency range (0-10 Hz) which is caused by long wavelength irregularities of track that causes discomfort. It is also observed that constant peak lateral responses occur at still lower frequency as compared to vertical response which again causes discomfort to vehicle riders. This concludes that there is a further scope of improvement in comfort level with minor adjustments of suspended equipment of a LHB coach. A sensitivity analysis based on the partial derivatives against FRF displacement is conducted and most sensitive design parameters are obtained for optimization to improve ride comfort. It is suggested that if the mass of bio toilet tanks and relative position of battery box + transformer unit i.e. most sensitive parameters of suspended equipment are changed then the ride comfort can be improved

Bridging the gap between life cycle inventory and impact assessment for toxicological assessments of pesticides used in crop production

This constitutes the second segment of an environmental life cycle assessment (LCA) study on oilseed rape cultivation in the prevalent conditions of Vojvodina, Serbia. The paper presents the results of the life cycle impact assessment (LCIA) phase of the LCA. The functional unit (FU) is one hectare of agricultural land used for winter rapeseed cultivation, with a reference flow of 3,000 kg of seeds, representing the average yield per hectare. The assessment is focused on the rapeseed production chain, concluding with the transportation of oilseeds to regional silos. The environmental impact assessment employed the ReCiPe 2016 (H) LCIA method, using the OpenLCA software. The study found that the total damage to human health was estimated at 0.0048 DALY, while damage due to biodiversity loss was calculated as 0.0001 species per year. Additionally, the damage resulting from the exploitation of geological mineral reserves was determined to be 167 USD per FU. Notably, land occupation was identified as the primary contributor to biodiversity loss, accounting for 90% of the associated damage within the rapeseed production chain. Meanwhile, the life cycle of diesel fuel, the mineral fertilizer production chain, and nitrogen compound emissions from agricultural land collectively accounted for 74% of the damage to human health and 91% of the damage attributed to mineral resource consumption. On the midpoint level, the ReCiPe 2016 (H) LCIA method calculates results within 18 impact categories, including the impact on global warming and fossil fuel depletion. The cumulative impact of greenhouse gases (GHG) emitted in the rapeseed production chain is equivalent to the impact of 1,970 kg of carbon dioxide. The carbon footprint of rapeseed was estimated at 0.65 kg CO2 eq. per kg of rapeseed. In the production chain of 3,000 kg of rapeseed, 454 kg of oil equivalent is consumed, which means that approximately 6.93 MJ of energy from fossil sources is required to produce 1 kg of rapeseed under the prevalent conditions in Vojvodina. The ReCiPe 2016 method identified and assessed the impact of approximately 750 different emissions with adverse effects on the environment, as well as the impact of around 250 different forms of natural resources consumed or used in the rapeseed production chain. However, the results of the LCIA analysis show that only about ten elementary flows are responsible for over 90% of the total damage in specific protection areas. These primarily include air emissions (carbon dioxide, ammonia, nitrogen oxides, nitrous oxide, sulphur dioxide, and suspended particles), emissions of certain heavy metals into water and soil (hexavalent chromium and zinc), as well as the exploitation of some natural resources, notably arable land, natural gas, and crude oil. The results of the LCIA analysis can be utilized to identify processes and emissions where rationalization or improved control can yield the greatest environmental benefits. The most substantial environmental improvements are expected through the reduction of mineral fertilizer consumption per unit yield and the decrease in diesel fuel usage for field and transportation activities. Furthermore, enhanced control over emissions that contribute significantly to the adverse impacts of the rapeseed production chain can also lead to substantial environmental enhancements.

Feeding a growing, increasingly affluent population while limiting environmental pressures of food production is a central challenge for society. Understanding the location and magnitude of food production is key to addressing this challenge because pressures vary substantially across food production types. Applying data and models from life cycle assessment with the methodologies for mapping cumulative environmental impacts of human activities (hereafter cumulative impact mapping) provides a powerful approach to spatially map the cumulative environmental pressure of food production in a way that is consistent and comprehensive across food types. However, these methodologies have yet to be combined. By synthesizing life cycle assessment and cumulative impact mapping methodologies, we provide guidance for comprehensively and cumulatively mapping the environmental pressures (e.g., greenhouse gas emissions, spatial occupancy, and freshwater use) associated with food production systems. This spatial approach enables quantification of current and potential future environmental pressures, which is needed for decision makers to create more sustainable food policies and practices.