Co-constructive development of a green chemistry-based model for the assessment of nanoparticles synthesis

Nanomaterials (materials at the nanoscale, 10−9m) are extensively used in several industry sectors due to the improved properties they empower commercial products with. There is a pressing need to produce these materials more sustainably. This paper proposes a Multiple Criteria Decision Aiding (MCDA) approach to assess the implementation of green chemistry principles as applied to the protocols for nanoparticles synthesis. In the presence of multiple green and environmentally oriented criteria, decision aiding is performed with a synergy of ordinal regression methods; preference information in the form of desired assignment for a subset of reference protocols is accepted. The classification models, indirectly derived from such information, are composed of an additive value function and a vector of thresholds separating the pre-defined and ordered classes. The method delivers a single representative model that is used to assess the relative importance of the criteria, identify the possible gains with improvement of the protocol’s evaluations and classify the non-reference protocols. Such precise recommendation is validated against the outcomes of robustness analysis exploiting the sets of all classification models compatible with all maximal subsets of consistent assignment examples. The introduced approach is used with real-world data concerning silver nanoparticles. It is proven to effectively resolve inconsistency in the assignment examples, tolerate ordinal and cardinal measurement scales, differentiate between inter- and intra-criteria attractiveness and deliver easily interpretable scores and class assignments. This work thoroughly discusses the learning insights that MCDA provided during the co-constructive development of the classification model, distinguishing between problem structuring, preference elicitation, learning, modeling and problem-solving stages

Comparison of tools for the sustainability assessment of nanomaterials

Nanomaterials are becoming widely used in areas such as biomedical applications, food, environmental protection, energy production, information technology and agriculture. As such, more research has been conducted on their synthesis and manufacturing from a variety of feedstocks. However, concerns regarding their impact on human health and the environment leads researchers to conduct a variety of ‘sustainability’ assessments. The purpose of this paper was to review the current opinion of sustainability assessments concerning nanomaterials. Major assessment tools were reviewed including life cycle assessment, risk assessment and multi-criteria decision analysis, along with subcategories. The review found that each assessment tool did positively contribute to sustainability assessments, but each also had drawbacks of varying degrees. In particular, multi-criteria decision analysis provides the most relevant tool for conducting a sustainability assessment as it can handle criteria of any typology and provide multiple types of decision recommendations, including rankings, scores and classifications

State-of-the-art and limitations in the life cycle assessment of ionic liquids

Even though the development and use of ionic liquids (ILs) has rapidly grown in recent years, in the literature, information addressing the environmental performance of these substances in a life cycle context is comparatively scarce. This review critiques the state-of-the-art environmental life cycle assessment (LCA) studies on ILs in the literature, identifies the existing shortcomings, which could be delaying complete employment of the LCA framework to the field of ILs, and also identifies strategies for overcoming these shortcomings. This review indicates that there are several limitations associated with the implementation of the LCA in all steps and discusses them. Since data about manufacturing at industrial scale are generally inaccessible, a set of methods and assumptions have been used in previous studies to determine the life cycle inventories (LCIs), such as simplified LCA, “tree life-cycle approach”, use of energy monitor devices, thermodynamic methods, chemical simulation process and other secondary data. However, the analysis of the data quality has not always been performed. Also, currently, there is a shortage of the characterization factors of ILs for human toxicity and ecotoxicity impact categories, which prevent its inclusion within the life cycle impact assessment (LCIA) step. Therefore, sufficient and complete life cycle inventory data for ionic liquids and precursor chemicals are essential for inventory analysis; and the LCIA needs to be clearly defined about the level of detail on the IL emissions. Current LCA studies on ILs have not covered all these aspects. To improve the present situation, it is proposed herein that for future LCA of processes involving ILs each of the LCA steps must be completed as far as scientific advances allow

State-of-the-art and limitations in the life cycle assessment of ionic liquids

Even though the development and use of ionic liquids (ILs) has rapidly grown in recent years, in the literature, information addressing the environmental performance of these substances in a life cycle context is comparatively scarce. This review critiques the state-of-the-art environmental life cycle assessment (LCA) studies on ILs in the literature, identifies the existing shortcomings, which could be delaying complete employment of the LCA framework to the field of ILs, and also identifies strategies for overcoming these shortcomings. This review indicates that there are several limitations associated with the implementation of the LCA in all steps and discusses them. Since data about manufacturing at industrial scale are generally inaccessible, a set of methods and assumptions have been used in previous studies to determine the life cycle inventories (LCIs), such as simplified LCA, “tree life-cycle approach”, use of energy monitor devices, thermodynamic methods, chemical simulation process and other secondary data. However, the analysis of the data quality has not always been performed. Also, currently, there is a shortage of the characterization factors of ILs for human toxicity and ecotoxicity impact categories, which prevent its inclusion within the life cycle impact assessment (LCIA) step. Therefore, sufficient and complete life cycle inventory data for ionic liquids and precursor chemicals are essential for inventory analysis; and the LCIA needs to be clearly defined about the level of detail on the IL emissions. Current LCA studies on ILs have not covered all these aspects. To improve the present situation, it is proposed herein that for future LCA of processes involving ILs each of the LCA steps must be completed as far as scientific advances allow

A semantic multi-criteria approach to evaluate different types of energy generation technologies

Multi-Criteria Decision Aid methods are used to find the best option from a set of alternatives when multiple and conflicting criteria have to be optimized simultaneously. The evaluation of the suitability or risk of each alternative is usually performed by assigning a numerical value. However, sometimes the data required to measure a criterion may be found in the form of semantic values such as tags. This paper proposes a methodology to calculate the strength of an outranking relation for a pair of alternatives using semantic criteria following the principles of ELECTRE-III (i.e. by means of concordance and discordance indices). The preferences about semantic data are represented in an ontology by means of objective and subjective functions. The paper explains how this new methodology was applied to analyse different electricity generation technologies using environmental and economic criteria. Two scenarios are tested to show how semantic criteria may influence the final decision

Harnessing plant extracts for eco-friendly synthesis of iron nanoparticle (Fe-NPs): Characterization and their potential applications for ameliorating environmental pollutants

Iron-nanoparticles (Fe-NPs) are increasingly been utilized in environmental applications due to their efficacy and strong catalytic activities. The novelty of nanoparticle science had attracted many researchers and especially for their green synthesis, which can effectively reuse biological resources during the polymerization reactions. Thus, the synthesis of Fe-NPs utilizing plant extracts could be considered as the eco-friendly, simple, rapid, energy-efficient, sustainable, and cost-effective. The green synthesis route can be recognized as a practical, valuable, and economically effective alternative for large-scale production. During the production process, some biomolecules present in the extracts undergo metal salts reduction, which can serve as both a capping and reducing mechanism, enhancing the reactivity and stability of green-synthesized Fe-NPs. The diversity of species provided a wide range of potential sources for green synthesis of Fe-NPs. With improved understanding of the specific biomolecules involved in the bioreduction and stabilization processes, it will become easier to identify and utilize new, potential plant materials for Fe-NPs synthesis. Newly synthesized Fe-NPs require different characterization techniques such as transmission electron microscope, ultraviolet-visible spectrophotometry, and X-ray absorption fine structure, etc, for the determination of size, composition, and structure. This review described and assessed the recent advancements in understanding green-synthesized Fe-NPs derived from plant-based material. Detailed information on various plant materials suitable of yielding valuable biomolecules with potential diverse applications in environmental safety. Additionally, this review examined the characterization techniques employed to analyze Fe-NPs, their stability, accumulation, mobility, and fate in the environment. Holistically, the review assessed the applications of Fe-NPs in remediating wastewaters, organic residues, and inorganic contaminants. The toxicity of Fe-NPs was also addressed; emphasizing the need to refine the synthesis of green Fe-NPs to ensure safety and environmental friendliness. Moving forward, the future challenges and opportunities associated with the green synthesis of Fe-NPs would motivate novel research about nanoparticles in new directions