Assessing photocatalytic asphalt mixtures: practical and laboratory methods for measuring air quality

Air pollution in urban areas has become a major global concern, leading to a series of programs and regulations to be implemented to reduce it. Among the various pollutants that affect air quality is nitrogen monoxide (NO), which, once in the atmosphere, oxidizes into nitrogen dioxide (NO2). The combination of NO and NO2 refer to the nitrogen oxides (NOx), which, besides being harmful to health, have a negative impact on the environment with acid rain and intensify the greenhouse effect. This issue is exacerbated in large cities due to the high concentration of pollutant-emitting vehicles. To mitigate this problem by cleaning the air, researchers are investing in photocatalytic capability that can be applied to the surface of various substrates. Titanium dioxide (TiO2) is a highly utilized material, especially when aiming to attain both photocatalytic and self-cleaning abilities. The application of TiO2 over asphalt pavements has become an important topic in Transportation Engineering as a way of functionalized conventional pavement into a substrate where it becomes feasible to alleviate the environmental damage related to pollutant emissions, mainly NOx. The application of photocatalytic materials on asphalt pavements has the necessary conditions to increase the success of reducing pollutant levels. Pavements present a large area and are closer to vehicle exhausts. In addition, a major part of asphalt pavements is exposed to sunlight, which can activate the photocatalytic reaction. Due to these benefits, researchers have conducted studies that evaluate photocatalytic efficiency on surfaces of asphalt pavements.When evaluating photocatalytic efficiency, the literature describes a series of methods based on laboratory and field tests. In the laboratory, efficiency can be evaluated by degrading different organic dyes and degradation gas tests. For the first method, some dyes are widely used, such as methylene orange (MO), methylene blue (MB) and rhodamine B (RhB). For testing, samples of asphalt mixtures are immersed in an initial dye solution and exposed to light irradiation. Over time, changes in the solution absorbance (and, consequently, concentration) are monitored using spectrophotometry. The photocatalytic efficiency is calculated as a function of the maximum absorbance of the dye and the time. The second test follows the ISO 22197-1 standard, which specifies a test method for determining the air purification performance of materials with photocatalysis on the surface. To simulate and ensure the photocatalytic reactions occur, the experimental setup must contain an air compressor, pollutant source, humidifier, photoreactor, light source and pollutant analyzer. The photocatalytic asphalt mixture sample is placed inside the photoreactor and exposed to a controlled amount of pollutants, light and humidity. The gas flow is continuously injected into the photoreactor and subjected to light irradiation, and gas concentration is monitored over a period of time. The photocatalytic efficiency can be assessed by the net amount of pollutants that the sample removes.In field applications, one method that can be used to evaluate the efficiency is the air quality monitoring stations by conducting a comparative analysis of pollutant concentrations in a specific area before and after installing photocatalytic asphalt pavements. Those stations have sensors that collect outdoor air and distribute it through analyzers. These analyzers continuously and automatically measure various atmospheric pollutants, determining their concentrations in the ambient air "in real-time". Typically, they are fixed at strategic points in large cities, limiting assessment in more remote locations. Usually, these stations can measure several types of pollutants, such as NOx, SO2, CO2, particulate matter, among others, and the meteorological conditions, for example temperature, relative humidity, wind speed and direction , etc. Another method to evaluate the performance in field studies is to use passive sampling. The passive sampling approach is a low-cost, non-electrical, and simplified solution for the distribution of samples. The principle of the passive sampler involves gas collection through the diffusion of atmospheric air, which enters the device through one of its ends, travels through the body of the sampler (in the form of a tube) until it reaches its other end, which is sealed and contains a filter paper previously impregnated with a specific absorbent solution designed to react with the targeted pollutant to be collected. Measurement of photocatalytic efficiency is crucial in determining the performance of photocatalytic pavements and their impact on air quality. Thus, this study aims to provide a comprehensive elucidation of how to evaluate the photocatalytic efficiency of photocatalytic asphalt pavements functionalized with TiO2 nanoparticles through various methods, encompassing laboratory approaches and field studies.This research was funded by FCT: NanoAir PTDC/FISMAC/6606/2020, MicroCoolPav EXPL/EQU-EQU/1110/2021, UIDB/04650/2020, UIDB/04029/2020, 2022.00763.CEECIND and 2023.02795.BD. Also, it was funded by FUNCAP: MLC-0191-00144.01.00/22 and CNPq: 404978/2021-5 – Chamada CNPq/MCTI/FNDCT Nº 18/2021.

Optimization of lipase production by Aspergillus ibericus from oil cakes and its application in esterification reactions

Due to the actual emphasis in revalorization of agro-industrial wastes and cost reduction of enzymes production, this work aimed the optimization of lipase production from different oil cakes (OCs) produced in Brazil, by solid-state fermentation using Aspergillus ibericus MUM 03.49 and the application of the produced lipase in hydrolysis and esterification reactions. Results presented showed higher lipase production using palm kernel oil cake (PKOC), yielding 127 ± 17 U/g. Through SSF optimization, using palm kernel oil cake (PKOC) mixed with sesame oil cake (SOC) in a ratio of 0.45 g/g PKOC per g total substrate at 57% moisture content, a production of 460 ± 38 U/g of lipase per mass of dry substrate was obtained after 6 days of fermentation. The obtained lipase was used in hydrolysis reactions, where it was observed higher production in short-chain triacylglycerols (TAGs) substrates. Also, it was applied in esterification reactions, where the formation of butyl decanoate using 5% (w/v) of biocatalyst was the most efficient. SSF of PKOC and SOC was a low cost competitive process to obtain A. ibericus lipase that can be used in aroma esters production, with application in the food industry.Felisbela Oliveira acknowledges the financial support from FAPERJ N° 43/2013—Programa de Apoio ao Doutorado-Sanduíche Reverso—2013, from Rio de Janeiro, Brazil and from the Portuguese Foundation for Science and Technology (FCT), through the grant SFRH/BD/87953/2012. José Manuel Salgado was supported by grant CEB/N2020 – INV/01/2016 from Project “BIOTECNORTE - Underpinning Biotechnology to foster the north of Portugal bioeconomy” (NORTE-01-0145-FEDER-000004). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Carlos E. Souza and Verônica R.O.L. Peclat thank the financial support given by CNPq and CAPES from Brazil, respectively. Bernardo D. Ribeiro and Maria A.Z. Coelho thank the financial support given by CNPq and FAPERJ from Brazil

Applied optics in the development of smart asphalt mixtures

The functionalization of asphalt mixtures is carried out in order to provide new capabilities to the road pavements, with major social, environmental and financial benefits. Optical characterization techniques as well as optical processes like photocatalysis play a major role in the development of new asphalt mixtures with smart functions. These advanced capabilities which are being developed in asphalt mixtures are: photocatalytic, superhydrophobic, self-cleaning, de-icing/anti-ice, self-healing, thermochromic, and latent heat thermal energy storage. The main objective of this research work is to stress the importance of optics and photonics technologies giving an overview of advanced functionalized smart asphalt mixtures.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UIDB/04650/2020. This work was partially financed by FCT - Fundação para a Ciência e a Tecnologia - under the projects of the Strategic Funding UIDB/04650/2020, MicroCoolPav project EXPL/EQU-EQU/1110/2021, and NanoAir project PTDC/FISMAC/6606/2020

Selection of indigenous lactic acid bacteria presenting anti-listerial activity, and their role in reducing the maturation period and assuring the safety of traditional Brazilian cheeses

Artisanal raw milk cheeses are highly appreciated dairy products in Brazil and ensuring their microbiological safety has been a great need. This study reports the isolation and characterization of lactic acid bacteria (LAB) strains with anti-listerial activity, and their effects on Listeria monocytogenes during refrigerated shelf-life of soft Minas cheese and ripening of semi-hard Minas cheese. LAB strains (n ¼ 891) isolated from Minas artisanal cheeses (n ¼ 244) were assessed for anti-listerial activity by deferred antagonism assay at 37 C and 7 C. The treatments comprised the production of soft or semi-hard Minas cheeses using raw or pasteurized milk, and including the addition of selected LAB only [Lactobacillus brevis 2-392, Lactobacillus plantarum 1-399 and 4 Enterococcus faecalis (1-37, 2-49, 2-388 and 1-400)], L. monocytogenes only, selected LAB co-inoculated with L. monocytogenes, or without any added cultures. At 37 C, 48.1% of LAB isolates showed anti-listerial capacity and 77.5% maintained activity at 7 C. Selected LAB strains presented a bacteriostatic effect on L. monocytogenes in soft cheese. L. monocytogenes was inactivated during the ripening of semi-hard cheeses by the mix of LAB added. Times to attain a 4 log-reduction of L. monocytogenes were 15 and 21 days for semi-hard cheeses produced with raw and pasteurized milk, respectively. LAB with anti-listerial activity isolated from artisanal Minas cheeses can comprise an additional barrier to L. monocytogenes growth during the refrigerated storage of soft cheese and help shorten the ripening period of semi-hard cheeses aged at ambient temperature.The authors thank the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) for financial support (Grants 13/ 20456-9, 14/14891-7, 15/25641-4, 16/21041-5, 16/12406-0 and 16/ 09346-5). Dr. Gonzales-Barron also acknowledges the financial support provided by the Portuguese Foundation for Science and Technology (FCT) through the award of an Investigator Fellowship (IF) in the mode of Development Grants (IF/00570). A.S. Sant'Ana acknowledges the financial support of “Conselho Nacional de Desenvolvimento Científico e Tecnológico” (CNPq) (Grant #302763/ 2014-7) and CAPES (Grant #33003017027P1).info:eu-repo/semantics/publishedVersio

Advancements in phase change materials in asphalt pavements for mitigation of urban heat island effect: bibliometric analysis and systematic review

This research presents a dual-pronged bibliometric and systematic review of the integration of phase change materials (PCMs) in asphalt pavements to counteract the urban heat island (UHI) effect. The bibliometric approach discerns the evolution of PCM-inclusion asphalt research, highlighting a marked rise in the number of publications between 2019 and 2022. Notably, Chang’an University in China has emerged as a leading contributor. The systematic review addresses key questions like optimal PCM types for UHI effect mitigation, strategies for PCM leakage prevention in asphalt, and effects on mechanical properties. The findings identify polyethylene glycols (PEGs), especially PEG2000 and PEG4000, as prevailing PCMs due to their wide phase-change temperature range and significant enthalpy during phase transitions. While including PCMs can modify asphalt’s mechanical attributes, such mixtures typically stay within performance norms. This review emphasises the potential of PCMs in urban heat management and the need for further research to achieve optimal thermal and mechanical balanceThis research was partially funded by the Portuguese Foundation for Science and Technology (FCT) under the framework of the projects MicroCoolPav EXPL/EQU-EQU/1110/2021, NanoAir PTDC/FIS-MAC/6606/2020, UIDB/04650/2020, and UIDB/04029/2020. This research was also supported by the doctoral Grant PRT/BD/154269/2022 financed by the FCT, and with funds from POR Norte-Portugal 2020 and State Budget, under MIT Portugal Program. I.R.S. would like to acknowledge the FCT for funding (2022.00763.CEECIND). V.C.B. acknowledges the Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico (Funcap), MLC-0191- 00144.01.00/22 (Edital Mulheres na Ciência), and the National Council for Scientific and Technological Development (CNPq), Process 404978/2021-5—Call CNPq/MCTI/FNDCT N° 18/2021—Faixa B—Consolidated Groups

Passive sampling for air quality assessment: proposal of an in-situ method to measure the efficiency of photocatalytic pavements

Currently, air pollution is a matter of great relevance due to its significant impact on human health. Semiconductor photocatalysis technology, known for its high efficiency and low environmental degradation, is considered a highly promising means to improve air quality. Asphalt pavements are commonly used in urban areas with high population concentrations. During the production cycle of these pavements, various air pollutants are emitted, primarily due to the high temperatures required for asphalt pavement. Photocatalysis using the semiconductor TiO2 has the capacity to degrade atmospheric NO under sunlight, which has sparked significant interest in photocatalysis technology and its applications.The bandgap, enduring physicochemical properties of the element, and its nontoxicity, along with its NO degradation capabilities, make TiO2 a highly viable option for photocatalysis. This study aims to elucidate how air quality is controlled through passive sampling for the quantification of nitrogen dioxide (NO2) in the atmosphere. Through this technique, it is possible to quantify the level of pollutants, in this case, NO2, present in the atmosphere at a selected location over a certain period of time.MicroCoolPav EXPL/EQU-EQU/1110/2021, UIDB/04650/2020, UIDB/04029/2020, 2022.00763.CEECIND and 2023.02795.BD. Also, it was funded by FUNCAP: MLC-0191-00144.01.00/22 and CNPq: 404978/2021-5 – Chamada CNPq/MCTI/FNDCT Nº 18/2021

Misturas asfálticas inteligentes: mito ou realidade?

A finalidade geral dos pavimentos rodoviários consiste na capacidade de resistir ao tráfego rodoviário e as ações meteorológicas, garantindo condições de rolamento seguras e confortáveis, com o menor dispêndio possível de recursos e danos sobre o meio ambiente. Um pavimento rodoviário é considerado inteligente quando possui funcionalidades adicionais ou capacidade de reagir a um estímulo externo. Estas aptidões podem ser incorporadas através da utilização de diversos materiais, por exemplo: nano/micropartículas (semicondutores e microcápsulas), materiais de mudança de fase, corantes e fibras. Dentre as novas capacidades, é possível destacar: fotocatálise, superhidrofobicidade, autolimpeza, degelo/anti-gelo, autorreparação, termocromismo e armazenamento de energia térmica latente. Algumas destas novas aptidões resultam da implementação de técnicas como: modificação de ligante asfáltico, revestimento por pulverização, espalhamento e incorporação volumétrica de componentes. Este trabalho revê as novas capacidades conferidas às misturas asfálticas, expõe informações sobre métodos de funcionalização, ensaios, materiais empregados e resultados e fornece recomendações para trabalhos futuros.The purpose of road pavements is to withstand road traffic and weather loads, while ensuring safe and comfortable driving conditions with the least possible expenditure of resources and damage to the environment. A road pavement is considered smart when it has additional abilities or capacity to react to an external stimulus. These abilities can be incorporated through various materials: nano/microparticles (semiconductors and microcapsules), phase change materials, dyes, and fibers. Among the new abilities added to asphalt mixtures are photocatalysis, superhydrophobicity, self-cleaning, de-icing/anti-icing, self-healing, thermochromism, and latent heat thermal energy storage. Some of these new capabilities result from different techniques, such as asphalt binder modification, spray coating, spreading, and volume incorporation of components. The present work reviews the new abilities conferred to asphalt mixtures, exposes the information about functionalization methods, tests, materials used and results, and provides recommendations for future work.Este trabalho foi apoiado pela Fundação para a Ciência e a Tecnologia (FCT) no âmbito dos projetos do Financiamento Estratégico UIDB/04650/2020, do projecto MicroCoolPav EXPL/EQU-EQU/1110/2021, e do projecto NanoAir PTDC/FISMAC/6606/2020. Os autores também agradecem pelo financiamento dos projetos MLC-0191-00144.01.00/22 (Edital Mulheres na Ciência Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico Funcap) e Processo 404978/2021-5, Chamada CNPq/MCTI/FNDCT Nº 18/2021 - Faixa B - Grupos Consolidados Conselho Nacional de Desenvolvimento Científico e Tecnológico CNPq)