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This paper investigates the structural transformation of dicalcium silicate (C2S) crystals brought about through boron doping. Both qualitative and quantitative analyses were conducted to explore the correspondence between boron content and the structure of dicalcium silicate. The results show that boron doping can stabilize β-C2S and the high-temperature phase α′H-C2S, and the structural transformation does not involve the modulation of α′L-C2S. There is a corresponding relationship between the unit cells of β-C2S and α′H-C2S, which can be transformed using a transformation matrix. The relationship between boron content and the content of different C2S structures, as well as the structural expressions for β-C2S and α′H-C2S, is determined using linear fitting and multivariable linear regression analysis. [ABSTRACT FROM AUTHOR]

Leachate is a substantial reservoir of per- and polyfluoroalkyl substances (PFASs) within the environment. However, comprehensive information on the occurrence and fate of PFASs in leachate, particularly in semi-arid and moderate-elevation regions where PFASs may aggregate, is lacking. Here, 13 legacy PFASs were investigated in leachate from landfills and an incineration plant in such area. PFASs concentrations ranged from 6063 to 43,161 ng·L -1 in raw leachate, influenced by leachate origin, climate, wastewater disposal, and especially bacterial communities. Bacteroidetes and Firmicutes were enriched in raw leachate, while Proteobacteria dominated during leachate treatment processes, possibly due to PFASs selection pressure. In addition, top 20 biomarkers indicated the potential of these bacterial indicators for PFASs detection. Tracing analysis also suggested that PFASs in groundwater may have originated from leachate and effluent from wastewater treatment plants. PFASs levels in groundwater showed a significant correlation with the presence of Brevundimonas, Leptothrix, Malikia, and Sphaerotilus. The pathogenic bacterium Brevundimonas suggested potential human health risks, while Leptothrix, Malikia, and Sphaerotilus may serve as indicators of groundwater contamination. This study is believed to provide insights into how to prevent and control PFASs-related environmental pollution., (Copyright © 2024. Published by Elsevier B.V.)