scholarly journals Self-Cleaning Coatings and Surfaces of Modern Building Materials for the Removal of Some Air Pollutants

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2161
Author(s):  
Anna Rabajczyk ◽  
Maria Zielecka ◽  
Wojciech Klapsa ◽  
Anna Dziechciarz

Air quality is one of the most important problems of the modern world, as it determines human health and changes occurring in other elements of nature, including climate change. For this reason, actions are taken to reduce the amount of harmful substances in the air. One such action is the use of building materials with special properties achieved by the application of self-cleaning coatings and photocatalytic additives. This article presents achievements in the field of additives and modifiers for building materials, whose task is to improve air quality. Concrete, cement, paints, and facade coatings modified based on the achievements of nanotechnology have been analyzed in terms of new properties and the possibility of their application in the area of modern environmental requirements. Both positive aspects and doubts were described in the scope of the effective reduction of the amount of gases such as VOC, NOx, dust and microorganisms.

2021 ◽  
Vol 8 (1) ◽  
pp. 1947007
Author(s):  
Ebenezer Leke Odekanle ◽  
Chinchong Blessing Bakut ◽  
Abiodun Paul Olalekan ◽  
Roseline Oluwaseun Ogundokun ◽  
Charity O. Aremu ◽  
...  

Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 250
Author(s):  
Chuloh Jung ◽  
Jihad Awad

Due to unprecedented urbanization, UAE had built many new residential projects with poor choices of material and ventilation. This social phenomenon is leading UAE to Sick Building Syndrome (SBS) faster than any other countries. The Dubai Municipality regulates the indoor air quality with strict stipulation, but the detailed regulations are still insufficient. The objective of this paper is to measure the indoor air quality of new residential projects in Dubai to suggest the improvement of the regulations for indoor air quality. As a methodology, a field survey was conducted to investigate the status of indoor air pollution in residential buildings. Based on the field survey data, lab experiments for building materials were conducted and a computer simulation on radon gas was conducted. The result had shown that radon gas was mainly detected in new townhouses and labor camp houses, and its concentration was found to exceed the standard. Volatile organic solvents (VOCs) and formaldehyde (CH2O) were mainly detected in showhouses and new townhouses, and the concentration distribution was about 10 times higher than that of outdoors. It was proven that emission concentration of radon gas from various building materials were detected, and the order was red clay, gypsum board, and concrete. Volatile organic solvents (VOCs) are mainly detected in oil paints and PVC floor and the radiation amount of all pollutants increased with temperature increase. In computer simulation, it was found that a new townhouse needs a grace period from 20 days to 6 months to lower the radon gas concentration by 2 pCi/L. This study will serve as a basic data to establish more detailed regulation for the building materials and improve the IAQ standards in Dubai.


Author(s):  
Zhiyuan Wang ◽  
Xiaoyi Shi ◽  
Chunhua Pan ◽  
Sisi Wang

Exploring the relationship between environmental air quality (EAQ) and climatic conditions on a large scale can help better understand the main distribution characteristics and the mechanisms of EAQ in China, which is significant for the implementation of policies of joint prevention and control of regional air pollution. In this study, we used the concentrations of six conventional air pollutants, i.e., carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), fine particulate matter (PM2.5), coarse particulate matter (PM10), and ozone (O3), derived from about 1300 monitoring sites in eastern China (EC) from January 2015 to December 2018. Exploiting the grading concentration limit (GB3095-2012) of various pollutants in China, we also calculated the monthly average air quality index (AQI) in EC. The results show that, generally, the EAQ has improved in all seasons in EC from 2015 to 2018. In particular, the concentrations of conventional air pollutants, such as CO, SO2, and NO2, have been decreasing year by year. However, the concentrations of particulate matter, such as PM2.5 and PM10, have changed little, and the O3 concentration increased from 2015 to 2018. Empirical mode decomposition (EOF) was used to analyze the major patterns of AQI in EC. The first mode (EOF1) was characterized by a uniform structure in AQI over EC. These phenomena are due to the precipitation variability associated with the East Asian summer monsoon (EASM), referred to as the “summer–winter” pattern. The second EOF mode (EOF2) showed that the AQI over EC is a north–south dipole pattern, which is bound by the Qinling Mountains and Huaihe River (about 35° N). The EOF2 is mainly caused by seasonal variations of the mixed concentration of PM2.5 and O3. Associated with EOF2, the Mongolia–Siberian High influences the AQI variation over northern EC by dominating the low-level winds (10 m and 850 hPa) in autumn and winter, and precipitation affects the AQI variation over southern EC in spring and summer.


2019 ◽  
Vol 289 ◽  
pp. 05004 ◽  
Author(s):  
Diana-Maria Mircea

Negative effects of environmental pollution pose a significant risk to agriculture, water resources and human health. This can however be reduced by selecting appropriate materials in construction and landscape architecture. It is well-known that strong sunlight or ultraviolet light decomposes many organic materials in a slow natural process. Photocatalytic substances accelerate this process and when used in concrete (which is one of the most widely used construction materials), permit the treatment of pollutants close to their source by applying a self-cleaning principle: decomposing organic materials, biological materials and pollutants into molecules like oxygen, water, carbon dioxide, nitrates, and sulphates. Catalytic material activation will start due to energy that is received from sunlight (it also can be activated using artificial lights), and self-cleaning begins when this material is activated. Beside other properties, this innovative self-cleaning concrete also keeps its colour for far longer than other traditional building materials, making it a desirable solution for landscaping applications.


2017 ◽  
Author(s):  
Jianlin Hu ◽  
Xun Li ◽  
Lin Huang ◽  
Qi Ying ◽  
Qiang Zhang ◽  
...  

Abstract. Accurate exposure estimates are required for health effects analyses of severe air pollution in China. Chemical transport models (CTMs) are widely used tools to provide detailed information of spatial distribution, chemical composition, particle size fractions, and source origins of pollutants. The accuracy of CTMs' predictions in China is largely affected by the uncertainties of public available emission inventories. The Community Multi-scale Air Quality model (CMAQ) with meteorological inputs from the Weather Research and Forecasting model (WRF) were used in this study to simulate air quality in China in 2013. Four sets of simulations were conducted with four different anthropogenic emission inventories, including the Multi-resolution Emission Inventory for China (MEIC), the Emission Inventory for China by School of Environment at Tsinghua University (SOE), the Emissions Database for Global Atmospheric Research (EDGAR), and the Regional Emission inventory in Asia version 2 (REAS2). Model performance was evaluated against available observation data from 422 sites in 60 cities across China. Model predictions of O3 and PM2.5 with the four inventories generally meet the criteria of model performance, but difference exists in different pollutants and different regions among the inventories. Ensemble predictions were calculated by linearly combining the results from different inventories under the constraint that sum of the squared errors between the ensemble results and the observations from all the cities was minimized. The ensemble annual concentrations show improved agreement with observations in most cities. The mean fractional bias (MFB) and mean fractional errors (MFE) of the ensemble predicted annual PM2.5 at the 60 cities are −0.11 and 0.24, respectively, which are better than the MFB (−0.25–−0.16) and MFE (0.26–0.31) of individual simulations. The ensemble annual 1-hour peak O3 (O3-1 h) concentrations are also improved, with mean normalized bias (MNB) of 0.03 and mean normalized errors (MNE) of 0.14, compared to MNB of 0.06–0.19 and MNE of 0.16–0.22 of the individual predictions. The ensemble predictions agree better with observations with daily, monthly, and annual averaging times in all regions of China for both PM2.5 and O3-1 h. The study demonstrates that ensemble predictions by combining predictions from individual emission inventories can improve the accuracy of predicted temporal and spatial distributions of air pollutants. This study is the first ensemble model study in China using multiple emission inventories and the results are publicly available for future health effects studies.


Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 431
Author(s):  
Ayako Yoshino ◽  
Akinori Takami ◽  
Keiichiro Hara ◽  
Chiharu Nishita-Hara ◽  
Masahiko Hayashi ◽  
...  

Transboundary air pollution (TAP) and local air pollution (LAP) influence the air quality of urban areas. Fukuoka, located on the west side of Japan and affected by TAP from the Asian continent, is a unique example for understanding the contribution of LAP and TAP. Gaseous species and particulate matter (PM) were measured for approximately three weeks in Fukuoka in the winter of 2018. We classified two distinctive periods, LAP and TAP, based on wind speed. The classification was supported by variations in the concentration of gaseous species and by backward trajectories. Most air pollutants, including NOx and PM, were high in the LAP period and low in the TAP period. However, ozone was the exception. Therefore, our findings suggest that reducing local emissions is necessary. Ozone was higher in the TAP period, and the variation in ozone concentration was relatively small, indicating that ozone was produced outside of the city and transported to Fukuoka. Thus, air pollutants must also be reduced at a regional scale, including in China.


2021 ◽  
Vol 02 ◽  
Author(s):  
Pernille D. Pedersen ◽  
Nina Lock ◽  
Henrik Jensen

: The NOx gasses (NO and NO2) are among the most important air pollutants, due to the toxicity of NO2, as well as the role of NOx in the tropospheric oxidation of Volatile Organic Carbons (VOCs), contributing to the formation of other hazardous air pollutants. Air pollution is one of the biggest health threats world-wide, hence reducing NOx levels is an important objective of the UN sustainable development goals, e.g. #3, “Good health and well-being” and #11 “Sustainable cities and communities”. Photocatalysis using TiO2 and light is a promising technique for removing NOx along with other pollutants, as demonstrated on laboratory scale. Furthermore, a long range of real-life test studies of varying scales have been conducted during the past two decades. The results of these studies have been conflicting, with some studies reporting no effect on the ambient air quality and others reporting significant reductions of NOx level. However, the studies are very difficult to compare and assess due to the very different approaches used, which consequently vary in quality. In this review, we aim to develop a set of objective evaluation criteria to assess the quality of the individual studies in order to simplify the interpretation and comparison of the existing studies. Moreover, we propose some guidelines for future test-studies. Furthermore, the approaches and main conclusions from 23 studies are independently assessed and discussed herein.


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