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    Probabilistic life cycle assessment of ash-based sintered lightweight aggregates manufactured with producer gas and coal-operated thermal power
    (Springer, 2025-09) Singh, Shamsher Bahadur; Barai, Sudhir Kumar
    The infrastructure growth in the world is expected to result in huge requirement of 12.5 billion tonnes of coarse aggregates in 2050. The utilization of artificial aggregates can pave a feasible pathway for tackling the issue of scarcity of natural aggregates. Life cycle assessment (LCA) is an environment management tool, which has been used for the large-scale acceptability of sintered flyash lightweight aggregates (SFLA) in the construction fraternity. The low quality of data inputs for LCA study induces bias and increase in uncertainty of evaluated impacts. In the current study, a probabilistic LCA framework has been developed for assessing the environmental impacts from the manufacturing of SFLA. The uncertainty distribution range in each of the input variables was identified and introduced in the model with the help of random numbers. In this study, uncertainty analysis is also carried out using Monte Carlo Simulation for the comparative analysis of baseline scheme with three alternative schemes of SFLA manufacturing process. Finally, the sensitivity analysis (SA) was also undertaken for studying the robustness of LCA model outputs. The global warming potential (GWP) for the baseline scenario is 198.6 kg CO2 eq. per t of SFLA. Three alternative schemes were proposed for which comparative impact assessment is carried out, which highlighted the GWP impacts reduces to 166.7 kg CO2 eq. per t of SFLA (16% lower), 142.6 kg CO2 eq. per t of SFLA (28% lower) and 123.4 kg CO2 eq. per t of SFLA (38% lower) for first, second and third alternative schemes respectively as compared to the baseline scheme. Sintering process is contributing highest to impact mainly due to emissions from combustion of coal present in raw mix, CO2 emissions from electricity consumed during the process and CO2 generated from producer gas production which is used for thermal energy in sintering process. The results of probabilistic LCA study show that there are significant variations in the coefficient of variation across the various unit processes and across the four impact categories.
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    Environmental impact of concrete
    (Springer, 2025-10) Barai, Sudhir Kumar
    Sustainable concrete production demands satisfaction of the two most important criteria such as optimization of resources and minimization of end-of-life wastes. As discussed in the previous chapters, one of the important ways in which this can be achieved is by using coarse recycled concrete aggregates (RCAs) as an alternative to natural coarse aggregates and other industrial wastes as supplementary cementitious materials (SCMs). In this regard, the role of a suitable mix design method for obtaining an optimum combination of concrete constituents is also significant. In this chapter, sustainability of 100% recycled coarse aggregate concrete (RAC) along with SCMs in concrete is explored through performing life-cycle assessment, especially focusing on concrete with coarse RCA and low-volume fly ash as cement substitute (denoted as FARAC) in concrete. The effect of particle packing method (PPM) of mix proportioning on the environmental impact of FARAC is assessed for a case study of India.
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    Biogenic nanoparticles: synthesis, characterization, applications and scaling up limitations in water treatment
    (Elsevier, 2025-10) Goonetilleke, Ashantha
    Nanoparticles (NPs) have attracted significant interest due to their unique chemical and physical properties. In this context, biogenic synthesis has emerged as a promising alternative, utilizing natural pathways (e.g., microorganisms and plants) to produce biomolecules such as polyphenols, vitamins, amino acids, and carbohydrates that can reduce and stabilize NP production. However, significant knowledge gaps remain, particularly regarding the interaction between biomolecules and metals, and their influence on the physicochemical properties of NPs. This review critically examines current biogenic synthesis methods and their applications in removing organic contaminants and inactivating microorganisms in water treatment. It also highlights the challenges and opportunities in this field. In terms of scalability, there are significant limitations currently. The variability in the composition of biological extracts makes it difficult to achieve reproducibility and control over NP size and morphology. Additionally, production processes tend to be slow and yields which lower than conventional chemical methods. Optimizing influential parameters such as biomolecule concentration, temperature, and pH remains a challenge. Finally, the lack of studies on toxicity and long-term stability hinders large-scale implementation.
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    Sustainable CO2 bio-mitigation: a life cycle perspective on chemolithotrophic conversion in bubble column bioreactors
    (RSC, 2025-09) Gupta, Suresh; Raghuvanshi, Smita
    The urgent need for low-carbon energy alternatives has intensified interest in sustainable biofuel production pathways. This study presents a comprehensive Life Cycle Assessment (LCA) of a chemolithotrophic bacterial platform for simultaneous CO2 mitigation and biodiesel production using Bacillus cereus SSLMC2 cultivated in 10 and 20 L bubble column bioreactors. Unlike phototrophic systems, this process leverages light-independent bacterial metabolism, offering year-round operation, high biomass yield, and compatibility with flue gas as a carbon source. Experimental data were integrated with LCA modeling using Umberto NXT Universal software and the ReCiPe 2016 and CML baseline methods to quantify environmental impacts across cultivation, biomass harvesting, lipid extraction, and transesterification stages. The results identify dewatering and homogenization as major environmental hotspots, contributing significantly to climate change, fossil depletion, and human toxicity categories. Endpoint analysis revealed human health and resource availability as the most impacted areas, primarily due to electricity use and chemical inputs. Cumulative energy demand assessments confirmed that scale-up from 10 to 20 L does not proportionally increase energy use, suggesting promising scalability. Recommendations include replacing centrifugation with membrane-based dewatering, solvent recovery systems, integration of renewable energy, and recycling of CO2 and water. This is the first LCA study to evaluate chemolithotrophic CO2 bio-mitigation coupled with biodiesel production at pilot scale using empirical data. The findings provide critical insights for optimizing microbial biorefineries and support the development of scalable, environmentally efficient carbon capture and utilization technologies.
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    Life cycle assessment of artificial sintered flyash lightweight aggregate produced in India using OFF gas and coal based thermal power
    (Springer, 2025-02) Singh, Shamsher Bahadur; Barai, Sudhir Kumar
    The potential environmental impacts associated with production of sintered flyash lightweight aggregate (SFA) needs comparison with natural aggregates (NA) which can directly help in the selection of sustainable materials. In the previously reported research, the impact of SFA manufacturing using off gas as thermal energy source is not assessed and site-specific data is also not available. Therefore, this study covers the life cycle assessment (LCA) of SFA production in India using coal based thermal power and off gas as source of thermal energy. In the present LCA study, all the inputs like raw materials, heat, electricity and outputs like product and emissions associated with production of SFA were inventoried, to evaluate the life cycle environmental impacts of SFA. The main purpose of this LCA study is to evaluate the alternative scenarios of making the SFA environment friendly by use of renewable energy and green fuels. Within the SFA manufacturing plant, a number of discrete unit processes were identified like raw material handling & mixing, palletization, sintering and screening and input–output analysis is undertaken for each unit process (including electricity and transportation). The impacts associated with SFA are compared with NA in terms of Global Warming Potential, Acidification Potential, Eutrophication Potential and Abiotic Depletion Potential. In this study, it was found that the environmental impacts associated with production of SFA are 55 to 90% higher as compared to NA. The Global Warming Potential impacts associated with 1 tonne of SFA are 83% higher as compared to 1.5 tonne of NA. Similarly, in terms of acidification potential and eutrophication potential, SFA are having 55% and 90% higher impacts as compared to natural aggregate respectively. The three alternative scenarios are developed based on contribution analysis. The alternative scenarios evaluated in this study are (a) electricity consumption based on 100% Solar power (b) biomass based OFF gas and electricity from coal based thermal power plant and (c) biomass based OFF gas and electricity from Grid. The study concludes that heat consumption in sintering process and electricity consumption in various unit processes are the main contributors for various environmental impacts in production process of SFA. The alternative routes like usage of biomass based OFF gas and grid-based electricity will help in reduction of environmental impacts associated with production of SFA and make it comparable with natural aggregates.
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    Novel LCA-centric mix design approach for alkali-activated EAF slag with hybrid optimization techniques
    (Springer, 2024-12) Lahoti, Mukund; Pradhan, Subhasis
    This study presents an innovative life cycle assessment (LCA)-centric approach for optimizing the mix design of alkali-activated materials (AAMs) as sustainable alternatives to ordinary portland cement (OPC). The AAMs are developed using electric arc furnace slag (EAFS) and fly ash as precursors. The environmental performance is evaluated using the ReCiPe midpoint methodology, considering both mass and economic allocation methods. The results indicate that global warming potential and terrestrial ecotoxicity are the primary environmental impact categories across all mixes and allocation scenarios. A Taguchi-based hybrid optimization technique, integrating gray relational analysis (GRA) and analytical hierarchical process (AHP)-weighted GRA, is employed to determine the optimal mix design based on fresh properties, mechanical performance, durability, and sustainability indices. The AHP-GRA analysis reveals that mixes containing at least 50% EAFS perform better than OPC in terms of overall sustainability. A blend of 75% EAFS and 25% fly ash is recommended for achieving the best balance between performance and environmental impact, offering a promising alternative for sustainable construction practices.
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    Development of a platform for supporting design for environment
    (ICED, 2007) Kota, Srinivas
    Individual guidelines often exist for DfE but these are not integrated with design tools. There is no comprehensive method that can be useful for the whole life cycle of a product in various stages of its design. Few tools exist that could aid iterative changes to a design required in product development and there is a need for an integrated methodology and computational support for designers. Life Cycle Assessment (LCA) [1] is arguably the most promising and scientifically defendable method for estimating environmental impacts of a product during its lifecycle [2]. Like DfE guidelines, LCA tools are not well integrated with design process and tools. Consequently, there is a need for an LCA tool integrated into the natural design process that can be applied to early as well as detailed design stages
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    Development of a method for estimating uncertainty in evaluation of environmental impacts during design
    (ICED, 2007-08) Kota, Srinivas
    Life Cycle Assessment (LCA) is currently the most promising and scientifically defendable technique for estimating environmental impacts of a product during its lifecycle. Currently, detailed LCA is critically dependent on high volumes of product specific data, time consuming, often unaffordable and used in the detailed stages of design. Current approximate LCA methods are either incomplete, inaccurate or require prior knowledge of what data is important. There is substantial uncertainty involved in the environmental impact calculations in LCA. Literature suggests that impact estimation results must be accompanied by an estimation of its uncertainty or imprecision, without which the decisions taken could be misleading. During development of a product, there is often a lack of accurate information about its structure, lifecycle stages, and related environmental impact information. As information about the product lifecycle continues to evolve during development, the assessment method should be such that it incorporates the different levels of abstraction about product information. A key result to be presented in this paper is a preliminary method developed using interval algebra and probabilistic theory taking product structure and lifecycle uncertainties into account. This method helps in estimating impact values of a product proposal in the earlier stages of design by providing an uncertainty value in terms of confidence on the result calculated, with the intention of supporting design decision making
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    Requirements for Design and Environmental Assessment of Products
    (Springer, 2022-11) Kota, Srinivas
    There are methods and technologies developed for generation and evaluation of product proposals for better environmental efficiency throughout the lifecycle. But in use phase these are not effective due to complexity of user behaviours and usage scenarios. Literature review revealed the need to develop products with the help of user to achieve sustainability. An outline of a conceptual system to include user in design is proposed in this chapter consisting of different dimensions based on the interactions and influences. It is important to consider how and where the user uses the product in reality while designing by including user also in design process. When different elements like people, product and environment come together, their individual characteristics, context in which they operate determine the interactions and influences among them. The questions need to be answered are identified to develop the proposed system.
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    Importance of User and Usage for Eco-Design
    (Springer, 2012-11) Kota, Srinivas
    There are methods and technologies developed for generation and evaluation of product proposals for better environmental efficiency throughout the lifecycle. But in use phase these are not effective due to complexity of user behaviours and usage scenarios. Literature review revealed the need to develop products with the help of user to achieve sustainability. An outline of a conceptual system to include user in design is proposed in this chapter consisting of different dimensions based on the interactions and influences. It is important to consider how and where the user uses the product in reality while designing by including user also in design process. When different elements like people, product and environment come together, their individual characteristics, context in which they operate determine the interactions and influences among them. The questions need to be answered are identified to develop the proposed system.