Environmental, Human Health and Socio-Economic Effects of Cement Powders: The Multicriteria Analysis as Decisional Methodology

Multiple criteria decision analysis to support the design of safe and sustainable chemicals and materials

The development of safe and sustainable chemicals and materials is essential to achieve the Zero-Pollution Ambition for a Toxic Free Environment stated in the EU Green Deal. For that, criteria need to be defined and considered since early stage of development. A Safe and Sustainable by Design (SSbD) framework is proposed in an EU Recommendation suggesting the assessment of multiple safety and sustainability aspects of chemicals and materials leaving open how the evaluation and selection of the preferable option should be done. This paper presents a proposal with different options for the use of multiattribute aggregation in an evaluation procedure for the SSbD assessment of chemicals and materials. This proposal is based on i) a review of the literature focusing on Multi-Criteria Decision Analysis (MCDA) application in the SSbD context (i.e. applications considering simultaneously safety and sustainability attributes) and ii) the definition of requisites for MCDA to be applied to the SSBD framework. In the latter, an absolute rather than a relative assessment is preferred as it should be possible for an organization developing a new chemical or material to assess if it is SSbD, without needing to obtain data on all of its possible competitors. Moreover, rank-reversals caused by the introduction of other options are avoided, i.e., assessments of one alternative that depends on other alternatives being assessed simultaneously are not the most adequate. Different options for the aggregation of attributes at different levels are discussed as well as for the consideration of data quality in the evaluation procedure. Regardless the approach selected, the use of multiattribute aggregation does not rule out a richer dashboard presenting not only the overall aggregate result, but also the results obtained in other levels of the hierarchy. Such complementary information is important to understand the strengths and weaknesses that an aggregate result might hide.

A systematic review on the impact of cement industries on the natural environment

The negative health effects of cement plant exposure are well-known in industrial settings, but they are less well-known among the general public who live near plants. The broad objective of the review was to provide a detailed systematic analysis of the global situation of the cement industry, including generation, pollution, impact on the natural ecosystem, technological and process improvements, sustainable models, the latest laws, challenges, needs, and ways forward. As an initial evaluation, a list of critical keywords was compiled, and a search of all accessible databases was conducted (i.e., Scopus, Web of Knowledge, Google Scholar). The manuscripts published in the journal between 2011 and 2021 were included. According to the findings, India is the second largest cement producer after China, with an installed capacity of 537 million tonnes and around 7.1 percent of the world's production, up from 337.32 million tonnes in 2019. NOx, SOx, CO, CO₂, H₂S, VOCs, dioxins, furans, and particulate matter are all common air pollutants from cement manufacturing. Other sources of dust particles include quarrying, blasting, drilling, trucking, cement plants, fuel production, packaging, path cleaning, and slabs. Other methods of reduction play an important part in decreasing industrial emissions, resulting in lower carbon and more sustainable products. The decision-making trial, in conjunction with the DEMATEL evaluation laboratory and the analytical hierarchy process (AHP) technique, will aid in determining the priority of climate alteration and mitigation options. Furthermore, employing sustainable techniques and technology, switching to alternative fuels will save 12% of total CO₂ emissions by 2050.

Environmental Benefit of Alternative Binders in Construction Industry: Life Cycle Assessment

Carbon dioxide (CO2) emissions associated with Portland cement (PC) production is ranked as the highest among the construction materials and it is estimated that 8% of the worlds CO2 discharges is due to PC production. As an average, the production of PC clinker including calcination process generates 0.81 kg of carbon dioxide per one kg of cement. Hence, new approaches which limit the negative environmental impacts of cement production and are aimed at the development of advanced methodologies are introduced. Implementation of lower energy consumption materials in production, which could moderately substitute PC in binders, can be addressed as one of the probable methods in mitigating environmental risks. Therefore, alternative binders fit into the most promising solutions. Present research investigates the environmental impact of the building sector, if an alternative to PC binder is used. Life cycle assessment (LCA) was used in this research to assess the environmental impact of the alternative ternary gypsum-PC-pozzolan binder in the production of mortar, and the environmental benefits were calculated and compared to traditional cement-based building materials. Phosphogypsum was considered as a secondary raw material, as in the current approach it is collected in open stacks bringing environmental concerns. SimaPro LCA software with the Ecoinvent database was used for most of the calculation processes. Results indicate that with alternative binders up to 30% of energy can be saved and 57 wt.% of CO2 emissions can be reduced, bringing positive impact on the construction industries contribution to the environment.

Coffee biowaste valorization within circular economy: an evaluation method of spent coffee grounds potentials for mortar production

PURPOSE

Spent coffee grounds (SCG) are biowastes extensively generated within the coffee supply chain. Nowadays, their disposal represents an increasing environmental concern due to its toxicity and organic nature. With the estimated increase of coffee production and consumption in the upcoming years, there is an imperative need to find a proper reverse option, along with a novel industrial application, which allows for the valorization of this coffee by-product within a circular economy perspective. This study aims at investigating a potential reuse of spent coffee grounds to produce novel construction materials to be used for sustainable buildings.

METHODS

After having illustrated the forward flows within the coffee life cycle and the potential reverse flow options, an evaluation method based on multi-criteria analyses was elaborated to test not only the technical but also the environmental and economic performances of novel materials originating from the incorporation of SCG as an aggregate in natural hydraulic lime and geopolymer-based mortars. Moreover, we focus on the reuse of another waste streams- biomass fly ash-deriving from the paper-pulp industry, rarely investigated in both traditional construction applications and in geopolymer manufacture. The two (geopolymer- and lime-based) mortar typologies are here studied and compared as potential green material for applications in construction, with satisfying engineering performance and high insulation attitude, giving a new life to a common organic waste. Consequently, we compare eight formulations by means of multi-criteria approaches that are nowadays claimed as a useful and effective decision aiding support instrument to assess the development of new sustainable construction materials. They permit to consider simultaneously some controversial and often uncertain aspects like technological (as the usual scientific studies do), environmental, and economic (more difficult to easily approach and evaluate). For this purpose, in this paper, we have analyzed the performance of the novel bio-composite mortars using VIKOR and TOPSIS methods to rank a set of alternatives according to various evaluation criteria that often conflict one with each other.

RESULTS

Results show that adding spent coffee grounds can efficiently improve the technical and sustainable performances of the novel mortars for different applications in the building sector. The presence of SCG increases water absorption and improves the insulation performance along with an environmental impact reduction. The considered technological properties are highly promising-such as the improvement in thermal insulation. In particular, even the addition of only 5% SCG leads to a significant reduction of the thermal conductivity and consequently to a greater insulating performance.

CONCLUSIONS

To date, most of the available literature on recycling SCG in construction materials do not consider mortar-based applications and, moreover, nor multi-criteria approaches. Therefore, our study proposes itself as an innovative track solution to food waste management lowering the employment of non-renewable natural resources and the costs associated to construction material production. At the same time, a novel and innovative way of such waste disposal is suggested, pursuing the sustainability and substantially reducing the environmental impact of construction and building materials. This study is a fundamental step in assessing the applicability of our designed and produced materials and its potentials to be produced at an industrial scale.

Analytical Method for Calculating Sustainable Airport Capacity

Capacity is the attitude of an airport to manage a number of operations in a given time interval within a fixed maximum delay (and under given safety conditions). Capacity studies are commonly carried out on five levels of analysis according to the required detail in order to identify the best option that balances economic, logistic and safety issues. This study focuses on level 3 (i.e., analytical methods) developing a calculation model to assess the runway capacity. The model was calibrated by comparing the outputs of different airport configurations with those provided by the circular of the Federal Aviation Administration Airport Capacity and Delay. The model was well calibrated with maximum differences in the analyzed configurations that stood at 1 or 2 movements/hour. The runway capacity of an international airport was calculated and compared to that of the entire airside, assessed through fast time simulation, in a previous study. The analytical model provides runway capacity slightly higher than that of the entire air system, as it cannot evaluate all the critical issues present in the airport that reduce its maximum theoretical capacity. Therefore, depending on the degree of detail required, you can use the developed model or the simulation software; the use of the latter is possible when the airside infrastructure does not adequately support the runway system or in cases of advanced design level.

Selection of Novel Geopolymeric Mortars for Sustainable Construction Applications Using Fuzzy Topsis Approach

Construction is recognized as one of the most polluting and energy consuming industries worldwide, especially in developing countries. Therefore, Research and Development (R&D) of novel manufacturing technologies and green construction materials is becoming extremely compelling. This study aims at evaluating the reuse of various wastes, originated in the Kraft pulp-paper industry, as raw materials in the manufacture of novel geopolymeric (GP) mortars whose properties fundamentally depend on the target application (e.g., insulating panel, partition wall, structural element, furnishing, etc.). Five different wastes were reused as filler: Two typologies of Biomass Fly Ash, calcareous sludge, grits, and dregs. The produced samples were characterized and a multi criteria analysis, able to take into account not only the engineering properties, but also the environmental and economic aspects, has been implemented. The criteria weights were evaluated using the Delphi methodology. The fuzzy Topsis approach has been used to consider the intrinsic uncertainty related to unconventional materials, as the produced GP-mortars. The computational analysis showed that adding the considered industrial wastes as filler is strongly recommended to improve the performance of materials intended for structural applications in construction. The results revealed that the formulations containing 5 wt.% of calcareous sludge, grits, and dregs and the one containing 7.5 wt.% of calcareous sludge, grits, dregs, and Biomass Fly Ash-1 have emerged as the best alternatives. Furthermore, it resulted that the Biomass Fly Ash-2 negatively influences the structural performance and relative rank of the material. Finally, this case study clearly shows that the fuzzy Topsis multi-criteria analysis represents a valuable and easy tool to investigate construction materials (either traditional and unconventional) when an intrinsic uncertainty is related to the measurement of the quantitative and qualitative characteristics.

Using system dynamics to assess the environmental management of cement industry in streaming data context

The cement industry can be regarded as one of the major sources of anthropogenic air pollution. It uses a significant amount of energy while creating substantial amount of potentially health-threatening carbon monoxide (CO), sulfur dioxide (SO₂), nitrogen oxides (NO_x) and dust particles. Hence, the cement industry can be regarded as a primary area for study in the development of green manufacturing. In this study, an urban cement factory is analyzed. The major contribution of the article is the development of a holistic approach to identify the variables impacting cement production and environmental factors creating air pollution in the area, a system dynamics model has been developed incorporating streaming data. To understand the effect of a cement factory on an urban area, some strategic level decisions are also analyzed with the study in order to reveal their impact on environment. The impact of cement production on air pollution cannot be evaluated separately from other air quality factors; therefore, the contribution of each factor has to be identified in order to understand the specific issues affecting a region. With the use of the model, future implications of various air quality factors on environmental sustainability can be assessed. According to the results, PM₁₀ value, which is currently above the World Health Organization (WHO) air pollution critical level of 50 μg/m³ for 30% of the days in a year, will climb to more than 50% in 2023. Moreover, governments can also recognize the severe impacts of location selection for cement industries, unplanned and excessive building licensing, and uncontrolled immigration on environment of an urban living. Therefore, output of the study is potentially beneficial in guiding governmental decisions to ensure the sustainability of air quality.

A Methodology to Evaluate Accessibility to Bus Stops as a Contribution to Improve Sustainability in Urban Mobility

Walking and transit are the backbone of sustainable mobility. Bus stops not only represent the connection between the two, but are also central in dictating the attractiveness of the latter. Accessibility of bus stops becomes, then, pivotal in increasing both attractiveness and sustainability of public transport. The paper describes a multi-step methodology to evaluate bus stops’ accessibility starting from a cluster of seven indicators describing objective and subjective features influencing passengers’ choice toward a given bus stop. The indicators are weighed by a questionnaire submitted to experts. Finally, a multicriteria analysis is developed to obtain a final score describing univocally the accessibility of each stop. Outcomes are mapped and a case study in Rome is reported as an example, with 231 bus and tram stops assessed accordingly. Results shows the relevance of the urban network and environment in evaluating the accessibility and in promoting more sustainable mobility patterns. Research innovation relies on the possibility to merge data from different fields into a specific GIS map and easily highlight for each bus stop the relationships between built environment, passengers’ comfort, and accessibility, with the concluding goal to provide advanced knowledge for further applications.

Life Cycle Analysis of Road Construction and Use

Both the construction and use of roads have a range of environmental impacts; therefore, it is important to assess the sources of their burdens to adopt correct mitigation policies. Life cycle analysis (LCA) is a useful method to obtain demonstrable, accurate and non-misleading information for decision-making experts. The study presents a “cradle to gate with options” LCA of a provincial road during 60 year-service life. Input data derive from the bill of quantity of the project and their impacts have been evaluated according to the European standard EN 15804. The study considers the impacts of the construction and maintenance stages, lighting, and use of the vehicles on the built road. The results obtained from a SimaPro model highlight that the almost half of impacts took place during the construction stage rather than the use stage. Therefore, the adoption of environmentally friendly road planning procedures, the use of low-impact procedures in the production of materials, and the use of secondary raw materials could have the largest potential for reducing environmental impacts.

Comparative Life Cycle Assessment of Lighting Systems and Road Pavements in an Italian Twin-Tube Road Tunnel

This work calculates and discusses the Life Cycle Assessment (LCA) of four scenarios composed of two types of road pavements and two types of lighting systems to be built in an Italian twin-tube road tunnel. A 20-year time horizon is adopted to assess the burdens of construction and maintenance of both flexible and rigid pavements and high-pressure sodium (HPS) and light-emitting diode (LED) lamps, traffic, and switching on of lamps. All considered scenarios are comparable with each other in terms of technical performances, but significantly differ regarding their environmental consequences. The geometrical and technical characteristics of the examined scenarios comply with current Italian standards for highways. In all the examined cases, LCA is carried out according to the European standard, EN 15804, and includes 19 impact categories (IC). The analysis demonstrates that the use of more reflecting surface pavement materials (i.e., concrete vs. asphalt) and more performing lighting systems (i.e., LED vs. HPS) can effectively mitigate the deleterious burdens related to road construction, maintenance, and use. For most of the examined ICs, the most environment-friendly scenario has LED lamps and concrete pavement.

Comprehensive Sustainability Evaluation of High-Speed Railway (HSR) Construction Projects Based on Unascertained Measure and Analytic Hierarchy Process

This paper aims to evaluate the sustainability of high-speed railway (HSR) construction projects in a comprehensive manner. To this end, the author established an index system, involving 4 primary indices, 9 secondary indices, and 32 tertiary indices. The analytic hierarchy process (AHP) and the unascertained measure were introduced to calculate the weights of these indices. Then, the index system was applied to evaluate the sustainability of the China’s Harbin-Dalian Passenger Dedicated Line (PDL). The results show that the Harbin-Dalian PDL project achieved good results in terms of process, economic benefit, impact, and sustainability, and will bring long-term benefits in the fields of tourism, economy, and transport capacity, as well as many other fields. In spite of its good overall sustainability, the project needs to further increase its economic benefits and reduce its negative environmental impact. For this purpose, it is necessary to adopt the management mode of “separation between network and transportation” and apply noise prevention measures like noise barriers, tunnels, and overhead viaducts. This research lays a solid basis for the sustainability evaluation of HSR construction projects, and simplifies the modelling process for designers of HSR.