13 research outputs found
Are you drowned in microplastic pollution? A brief insight on the current knowledge for early career researchers developing novel remediation strategies
Microplastics (MPs) composed of different polymers with various shapes, within a vast granulometric distribution (1 μm - 5 mm) and with a wide variety of physicochemical surface and bulk characteristics spiral around the globe, with different atmospheric, oceanic, cryospheric, and terrestrial residence times, while interacting with other pollutants and biota. The challenges of microplastic pollution are related to the complex relationships between the microplastic generation mechanisms (physical, chemical, and biological), their physicochemical properties, their interactions with other pollutants and microorganisms, the changes in their properties with aging, and their small sizes that facilitate their diffusion and transportation between the air, water, land, and biota, thereby promoting their ubiquity. Early career researchers (ERCs) constitute an essential part of the scientific community committed to overcoming the challenges of microplastic pollution with their new ideas and innovative scientific perspectives for the development of remediation technologies. However, because of the enormous amount of scientific information available, it may be difficult for ERCs to determine the complexity of this environmental issue. This mini-review aims to provide a quick and updated overview of the essential insights of microplastic pollution to ERCs to help them acquire the background needed to develop highly innovative physical, chemical, and biological remediation technologies, as well as valorization proposals and environmental education and awareness campaigns. Moreover, the recommendations for the development of holistic microplastic pollution remediation strategies presented here can help ERCs propose technologies considering the environmental, social, and practical dimensions of microplastic pollution while fulfilling the current government policies to manage this plastic waste
Chapter 16: Mitigation Strategies for Microfiber Pollution
In this chapter, an outline of the available strategies for mitigating microfiber contamination is presented. As most of the microfibers enter the environment from the washing of synthetic clothing, most mitigation strategies have mainly focused on preventing microfiber discharge from domestic and industrial washing of synthetic garments. First, efforts have been made to assess the impact of a few washing parameters that affect the discharge of microfibers, with the aim of designing washing programs with minimal discharges. Other endeavors related to washing practices incorporate devices designed to capture microfibers in domestic (in-drum or external) or industrial washing (ceramic membranes). Additional techniques for mitigating microfiber contamination incorporate modifications to the composition and structure of standard synthetic fabrics and educational and awareness campaigns. As none of these strategies are 100% efficient in preventing microfiber release, they can be complemented with conventional wastewater treatment plants that can capture microfibers that escape other mitigation strategies. The recuperated microfibers can be reused as raw materials within the building sector or in pyrolysis to generate oil, gas, and char
Towards a Microplastic-Free Ocean: Green Photocatalysis for Mitigation of Micro- and Nanoplastic Marine Pollution
The presence of microplastics (MPs) or nanoplastics (NPs) in the ocean is one of our society's most pressing environmental issues. MPs and NPs cause health issues to the biota that consumes them and are being transferred throughout the tropic chain up to humans. Since MPs and NPs are first produced in upstream processes, reducing MPs inputs through management before introducing them to aquatic ecosystems is the best option to protect the ocean. Photocatalysis is a water treatment process that can achieve this goal. In this research, visible light photocatalysis in aqueous medium of polyethylene (PE), polystyrene (PS) and polyethylene terephthalate (PET) MPs and NPs was investigated using N-TiO2, C,N-TiO2 and C,N-TiO2/SiO2. The influence of pH, temperature, MPs' size and the semiconductor's form (powders or films) on the removal process was tested. All the variables influenced degradation and photocatalysis can reach in some cases 70% of MPs removal in 50 h of reaction. This information can guide the design of photocatalytic systems that reduce MPs pollution
Evaluation of the correlations between temperature, humidity, incident UV light and the photocatalytic activity of TiO2films using a rationale approach
The effect of temperature, humidity and incident UV light on the photocatalytic activity of two TiO2filmswith different microstructures (dense and mesoporous) was explored in terms of stearic acid degradation.Previous works reported in the literature suggest that the activity of TiO2films does not only depend onsingle factors but also on interactions between them. Hence, the design of experiments (DoE) approachwas used in this work to plan the experiments in a systematic way, simultaneously considering severalvariables. This approach provided an efficient working strategy to explore both individual and interactioneffects on the photocatalytic activity of the films. The statistical evidence found here revealed that singlefactors temperature and mesoporous microstructure have the strongest positive effect on the efficiencyof the films. In the case of temperature, this was explained by easier degradation and/or desorption ofreaction intermediates. On the other hand, the positive effect of the mesoporous microstructure wascorrelated with its large surface area. An interaction factor between temperature and incident UV lightalso affects the activity of the films. Results suggest that this phenomenon depends of the degree of filmhydration before the deposition of SA
Frit-Free solar reflective porcelain stoneware ceramic tiles using recycled granite Waste: An investigation on its engobe and glaze formulations
The design of tiles can accelerate the transition of urban environments towards sustainability when building materials are prepared with sustainable, indigenous, renewable or recycled resources and additionally, present solar reflective properties for mitigating the Urban Heat Island (UHI) phenomenon. Here, an innovative approach to develop frit-free ceramics having solar reflectance property using locally sourced recycled granite waste was explored. The investigation unfolds in three parts: (i), the formulations were tailored for the engobe or glaze by varying raw material proportions; (ii), the solar reflectance was improved using whitening agents; and (iii), the selected formulations were subjected to an industrial trial casting of porcelain stoneware tiles. The full replacement of nepheline and feldspar with recycled granite powder offered properties suitable for the engobe such as a matte surface with high roughness and low gloss, while the same was identified to be less suitable in the glaze. The glaze formulation without any industrial frits was achieved by altering the proportions of nepheline and feldspar in the matrix. The solar reflectance of the engobe was enhanced by adding 10% of fine-grained zircon. The industrial trial showed that the developed formulation retained its conventional characteristics and superior functional performance in stain and chemical resistance
Improvement of the Adhesion Between TiO2 Nanofilm and Glass Substrate by Roughness Modifications
AbstractAn increase of the adhesion between soda-lime glass substrate and TiO2 nanofilm was achieved by roughness modifications, treating the glass surface with acid or basic solutions. The study was organised through a D-optimal experimental design. The roughness (measured by AFM) and the weight loss were statistically analysed using MODDE 9.0 software. Subsequently, the correlation between the surface roughness and the adhesion (measured by scratch test) of the films was studied. The statistic analysis of the results indicates how the chemical treatments modify the roughness of the glasses and it was found that smooth surfaces enhance the adhesion of the films
Correlating the physico-chemical properties of two conventional glazed porcelain stoneware tiles in relation to cleanability and sanitization
Keeping surfaces clean can reduce the spread of infections. In particular, to decrease the potential for SARS CoV-2 contamination, performing disinfection of high-touching surfaces. Several ceramic tiles and porcelain stoneware tiles with antimicrobial properties are already available on the market. However, the widespread use of antimicrobial glazed stoneware tiles may require to replace the ceramic surfaces already present in many buildings. The unfeasibility of such replacement can be due to both product durability (lifetime of a tile is usually long) and/or monetary restrictions. Furthermore, as porcelain stoneware per se does not have antimicrobial activity, these materials are fabricated by adding chemical agents able to provide antimicrobial properties. This approach requires a compatibility between the antimicrobial agents and the glaze formulation, as well as a careful control of the firing cycle and the final properties of the ceramic products. It follows that the final cost of antimicrobial tiles is not competitive with that of conventional tiles. In the latter, the persistence of potential pathogens on the surfaces is a crucial problem to face: the longer a pathogen survives on a surface, the longer it may be a source of transmission and thus endanger susceptible subjects. In this work, bacteria's capacity to adhere and to be effectively removed from two conventional glazed porcelain stoneware tiles (under dirty and clean conditions) was investigated. Two different glazes were tested, one mainly glassy (glossy) and the other mainly crystalline (matt). The sanitization procedures were carried out by chemical and chemo-mechanical procedures. The results showed that chemo-mechanical sanitization was the most effective, and the best results could be obtained on the stoneware tiles coated with the mainly glassy glaze, with the lowest porosity and the lower roughness values and water contact angles, especially under clean conditions
New strategy for microplastic degradation: Green photocatalysis using a protein-based porous N-TiO2 semiconductor
Currently, the global community considers microplastics as a marine pollutant of emerging concern. To mitigate
the oceanic microplastic pollution, it is necessary to reduce inputs from inland. In this sense, we present the first
report on the use of photocatalysis for the degradation of HDPE microplastics extracted from a commercially
available facial scrub. This was achieved by using two proposed semiconductors based on N-TiO2. One was green
synthesized using the extrapallial fluid of fresh blue mussels, which presented an excellent capacity to promote
photocatalytic degradation in solid and aqueous environments; while the second photocatalyst, obtained from a
conventional sol-gel synthesis, presented good capacity to promote mass loss of the as-extracted microplastics in
an aqueous environment. Mass losses, SEM and FTIR analysis confirmed HDPE degradation. Results showed that
environmental conditions, microplastics/N-TiO2 interaction and the N-TiO2 surface area should be carefully set and
monitored in order of avoiding the arrest of photocatalysisCurrently, the global community considers microplastics as a marine pollutant of emerging concern. To mitigate the oceanic microplastic pollution, it is necessary to reduce inputs from inland. In this sense, we present the first report on the use of photocatalysis for the degradation of HDPE microplastics extracted from a commercially available facial scrub. This was achieved by using two proposed semiconductors based on N-TiO2. One was green synthesized using the extrapallial fluid of fresh blue mussels, which presented an excellent capacity to promote photocatalytic degradation in solid and aqueous environments; while the second photocatalyst, obtained from a conventional sol-gel synthesis, presented good capacity to promote mass loss of the as-extracted microplastics in an aqueous environment. Mass losses, SEM and FTIR analysis confirmed HDPE degradation. Results showed that environmental conditions, microplastics/N-TiO2 interaction and the N-TiO2 surface area should be carefully set and monitored in order of avoiding the arrest of photocatalysis
METALLURGICAL WASTE VALORIZATION FOR FABRICATING GLASS-CERAMICS MATERIALS
The valorization of a metallurgical waste (i.e., an iron-rich slag) as raw material for the fabrication of high hardness glass-ceramics using differential thermal analysis, X-ray diffraction, X-ray fluorescence and scanning electron microscopy was investigated. The melting of the slag was aided by the addition of waste glass cullet (WGC) and the vitrification field of this system was investigated. The non-isothermal crystallization kinetics of the parent glass with the highest slag content was studied by DTA and crystallization of the parent glasses led to of pyroxenic crystalline phases, suggesting the application of the obtained glass-ceramics as building materials. Environmental benefits such as the reduction in the consumption of virgin raw materials and the elimination or reduction of CO2 and SO2 emissions due to absence of carbonates and sulphates in the batch composition make it an interesting alternative for the application of this technology
WRITING EFFECTIVE ENGINEERING RESEARCH PAPERS: A BRIEF GUIDE FOR NEW WRITERS
Publishing engineering research papers not only can facilitate funding but can also boost academic promotion. When researchers apply for an academic position or a new job, they must demonstrate their productivity based on the number and quality of their published articles. However, writing engineering research papers is a difficult and daunting task, especially for beginners. Many books and articles explain and provide guidelines on how scientific papers should be written, organized, and structured, including those that explain techniques to avoid imperfections and those that provide instructions for submission and publishing. However, they rarely provide unwritten rules for achieving success in the field of engineering. The aim of this paper is to focus on simple suggestions, useful tips, and unwritten rules for writing engineering research papers. This article provides a brief guide for new writers