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A laser-induced breakdown spectroscopy (LIBS) technique has been applied for detection of unburned carbon in fly ash, and an automated LIBS unit has been developed and applied in a 1000-MW pulverized-coal-fired power plant for real-time measurement, specifically of unburned carbon in fly ash. Good agreement was found between measurement results from the LIBS method and those from the conventional method (Japanese Industrial Standard 8815), with a standard deviation of 0.27%. This result confirms that the measurement of unburned carbon in fly ash by use of LIBS is sufficiently accurate for boiler control. Measurements taken by this apparatus were also integrated into a boiler-control system with the objective of achieving optimal and stable combustion. By control of the rotating speed of a mill rotary separator relative to measured unburned-carbon content, it has been demonstrated that boiler control is possible in an optimized manner by use of the value of the unburned-carbon content of fly ash.
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http://dx.doi.org/10.1364/ao.42.006159 | DOI Listing |
Arch 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.
View Article and Find Full Text PDFPLoS One
September 2025
School of Chemical Engineering, University of New South Wales, Sydney, New South Wales, Australia.
Coal blending in thermal power plants is a complex multi-objective challenge involving economic, operational and environmental considerations. This study presents a Q-learning-enhanced NSGA-II (QLNSGA-II) algorithm that integrates the adaptive policy optimization of Q-learning with the elitist selection of NSGA-II to dynamically adjust crossover and mutation rates based on real-time performance metrics. A physics-based objective function takes into account the thermodynamics of ash fusion and the kinetics of pollutant emission, ensuring compliance with combustion efficiency and NOx limits.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
September 2025
School of Energy Science and Engineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
This present investigation focuses on desulphurization of high sulphur North-East Indian coal under ultrasonic and microwave irradiation-aided chemical leaching. The powdered coal was treated under four different conditions, such as alkali leaching under low-energy ultrasound energy (US), acid leaching under ultra-high frequency microwave energy (MW), ultrasonic followed by microwave treatment (US-MW) and microwave followed by ultrasonic treatment (MW-US). The ultrasonic treatment was conducted using 0.
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