An Analysis of Nanoparticles Derived from Coal Fly Ash Incorporated into Concrete

Abstract

The environmental benefits of incorporating coal fly ash (CFA) into the concrete manufacturing process as a partial substitute for Portland cement are well known. What is less studied is the potential release of CFA derived nanomineral and amorphous nanoparticles during this process of incorporation. A thorough understanding of this makes it possible to understand the risks of exposure to particulates that are harmful to human health when CFA is mixed into concrete. The general objective of this study is to analyze airborne particulates released when CFA is mixed into concrete at the point of manufacture, focusing on the levels of nanominerals, amorphous nanoparticles and hazardous elements (HEs) contained within that are considered harmful to human health. These airborne particulates can be easily inhaled by plant workers in the absence of personal protective equipment. The authors analyzed samples of ash itself and collected actual airborne particulates using self-made passive samplers installed at the manufacturing plant. Regarding the ash analyzed, iron (Fe) was found in large amounts in relation to calcium (Ca), magnesium (Mg) and silicon (Si). The transport, disposal and application of CFA in civil construction projects can provide an increased efficiency and reduce overall costs associated with the production of concrete. However, CFA poses a threat to human health due to the significant amount of HEs, nanominerals, and amorphous nanoparticles found to be released into the environment at the manufacturing plant.

Hazardous Elements in Sediments Detected in Former Decommissioned Coal Mining Areas in Colombia: A Need for Environmental Recovery

“…One can highlight the use of multi-analytic studies using FE-SEM, HR-TEM, Mossbauer spectroscopy, petrology, X-ray diffraction, Raman spectroscopy, and complex chemical characterization (e.g., ion-pair chromatography coupled to inductively coupled plasmamass spectrometry and liquid chromatography/electrospray ionization/tandem mass spectrometry) of SCC and its associated environmental impacts as well as human health risks have been evaluated by many scientific groups around the world [15][16][17]. The number of studies that reassess the impacts of SCC over the years is reduced, through the resampling of previously sampled locations, enabling quantitative analysis of hazardous elements in coal mining areas with more accurate results and realistic attributes quantitatively assigned in the environment [18,19].…”

Brazilian Coal Tailings Projects: Advanced Study of Sustainable Using FIB-SEM and HR-TEM

“…Three southern Brazilian states, Paraná, Santa Catarina and Rio Grande do Sul, are responsible for the majority of mineral coal mining that occurs in Brazil and that is aimed at feeding thermoelectric power plants generating Brazilian electricity [25][26][27][28]. These studies [25][26][27][28], carried out with coal in the southern region of Brazil, raise concerns related to the negative impacts attributed to environmental quality that are capable of covering large regions, generating environmental unsustainability. Of the three states mentioned above (Paraná, Santa Catarina and Rio Grande do Sul), the state of Santa Catarina contains 80% of Brazil's known coal reserves, totaling approximately seven layers of coal in areas destined for mining activities [27,29].…”

“…The majority of Santa Catarina 200+ coal mines are open pit mines, accounting for 3,643,000 tons of coal extracted annually, which represents a total of 50% of the mineral coal extracted in Brazil [27,30]. Globally, coal-fired power plants account for 38% of the world's energy generation [28,30].…”

“…The chemical composition of coal tailings depends on their geological formation [31]. Not all coal is created equal and geographic disparities result in different elemental concentrations in different coal deposits [27,28,30]. Several authors who have studied coal tailings in different countries have reported enormous variability in chemical and mineralogical compositions exhibited by mineral coal [21,27,30,32,33]; therefore, identification of possibilities for improvements in the extraction of high-value materials in coal areas is of paramount importance [34,35].…”

Editorial: Nano- and Micro-Contaminants and Their Effect on the Humans and Environment

“…Thus, the use of a Technosol presupposes a much faster recovery without the need for any other type of intervention. On the other hand, the environmental benefits of incorporating coal fly ash (CFA) into the concrete manufacturing process as a partial substitute for Portland cement are well known [2]. What is less studied is the potential release of CFA-derived nanominerals and amorphous nanoparticles during this process of incorporation.…”