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Sequential extraction has been validated as an effective method to assess the fractions of elements in fly ash. However, the time consumption and high labor costs limit the application of the conventional sequential extraction (CSE) for fast screening of elemental fractions in fly ash. In this study, two ultrasound-assisted sequential extraction (UASE) methods were developed for fast analysis of arsenic (As) and selenium (Se) fractions in fly ash (FA). The parameters of UASE were optimized by comparing the results of As and Se obtained from UASE with those values observed CSE. The operation time of sequential extraction procedures for As and Se were shortened from 24.5 h to less than 90 min. A certified reference material (CRM, GBW08401) and real fly ash samples were applied to validate the developed UASE. The recoveries of As and Se were found in the range of 82.3% to 114%. For all fractions, the performance of UASE was faster than CSE with the acceptable uncertainties. The analytical results demonstrated that the concentration of As in F3 was found to be higher than other fractions, while the main forms of Se were found to be in F1 and F3 in the fly ash samples. Based on the advantages of high efficiency and easy operation, the developed UASE procedures can be applied for fast screening of the mobility and bioavailability of As and Se in FA from coal fired power plants.
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http://dx.doi.org/10.1039/c9ra08481a | DOI Listing |
Bioresour Technol
September 2025
State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China.
The pyrolysis of flue-cured tobacco stalks (TS) faces challenges such as low bio-oil value and utilization efficiency. Existing studies have overlooked the anatomical heterogeneity of tobacco stalks, thereby limiting the directional regulation of high-value components, such as nicotine and phenolic compounds. This study divides TS into the husk (TSH), xylem (TSX), and pith (TSP), and investigates their physicochemical properties, pyrolysis behavior (through TGA and fixed-bed pyrolysis experiments), and interactions.
View Article and Find Full Text PDFEnviron Res
September 2025
National Key Laboratory of Deep Coal Mining Safety and Environmental Protection, Anhui University of Science and Technology, Huainan, 232001, Anhui, China.
Zeolite synthesis from fly ash offers recycling and environmental benefits for carbon dioxide capture, but varying fly ash composition from different sources has different compositions, leading to inconsistent adsorption results. To achieve high CO adsorption performance and stability in zeolite synthesis from fly ash systems, this study established an element-controlled simulated fly ash system with Ca/Fe gradient differences. Hydrothermal synthesis yielded zeolites with optimized oxide ratios for CO adsorption.
View Article and Find Full Text PDFArch Environ Contam Toxicol
September 2025
Ecole Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering, 1015, Lausanne, Switzerland.
Pollution from past industrial activities can remain unnoticed for years or even decades because the pollutant has only recently gained attention or been identified by measurements. Modeling the emission history of pollution is essential for estimating population exposure and apportioning potential liability among stakeholders. This paper proposes a novel approach for reconstructing the history of polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) pollution from municipal solid waste incinerators (MSWIs) with unknown past emissions.
View Article and Find Full Text PDFEnviron Res
September 2025
Materials Science, Engineering, and Commercialization (MSEC) Program, Texas State University, San Marcos, TX-78666, USA; Department of Engineering Technology, Texas State University, San Marcos, TX-78666, USA.
Fly ash (FA) landfills are overflowing with materials, and unexplored waste streams like waste spent garnet (WSG) and waste foundry sand (WFS) are often dumped in onsite storage spaces, limiting land availability for future use and exacerbating environmental concerns related to waste disposal. Therefore, this research proposes recycling FA to produce reclaimed FA (RFA) as a binder, replacing 40-60% of ground granulated blast furnace slag (GGBFS) and 30-50% of river sand (RS) with WSG and WFS to produce geopolymers. The performance of geopolymers was assessed under different curing regimes, including ambient-temperature curing (ATC), ambient-temperature water curing (AWC), high-temperature curing (HTC), and high-temperature water curing (HWC).
View Article and Find Full Text PDFJ Environ Manage
September 2025
Interdisciplinary Research Center for Construction and Building Materials, Department of Materials Science and Engineering, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia.
The disposal of municipal solid waste incineration fly ashes (MSWI-FA) is complicated by soluble chlorides, which increase the risk of heavy metals (HMs) leaching toxicity and hinder the further use of remediated MSWI-FA. In this study, the self-assembly potentiality of magnesium oxychloride cement (MOC) in geopolymerization was explored and utilized to enhance the solidification/stabilization (S/S) of the MSWI-FA. The MOC-self-assembled geopolymerization kinetics can be suitably described by the JMAK model.
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