The high mobility of chromium (Cr) caused by acid mine drainage (AMD) poses a serious threat to the aquatic environment. Weakly crystalline minerals can passivate Cr and modify its environmental behavior. Dissolved organic matter (DOM) plays an important role in synergizing the in-situ immobilization of Cr by minerals. However, few studies have explored the molecular-level impact of DOM on Cr immobilization by inducing weakly crystalline minerals transformation. Here, we investigated the effects and mechanisms of sludge-derived DOM (with rich molecular diversity) on Cr immobilization by jarosite (KJ, widely present in AMD). The results showed that sludge-derived DOM significantly changed the speciation distribution of Cr and Fe. The maximum enhancement of Cr immobilized via adsorption and precipitation was 63.43 % and 161.89 %, respectively. Synchronous fluorescence analysis showed that the fractionation of high-oxygenated aromatic compounds promoted Cr adsorption on KJ. FT-ICR-MS spectra suggested that low-oxygenated aromatic and aliphatic compounds promote Cr immobilization in secondary ferrihydrite by capturing free Cr, followed by coprecipitation with dissolved Fe ions. The molecular-level finding in this study will facilitate the deep understanding of the molecular selectivity of sludge organics in remediating heavy metal-contaminated environments, and is of great significance for realizing the resource utilization of enormous waste sludge.
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http://dx.doi.org/10.1016/j.jhazmat.2025.137743 | DOI Listing |
Environ Sci Technol
March 2025
Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China.
Humic-like substances (HULIS) widely exist in the atmosphere and may strongly affect human health, environment, and climate. However, there are still no accurate methods for detecting the vertical distribution of HULIS. Here, a Raman-Polarization-Fluorescence Spectroscopic Lidar (RPFSL) was developed to simultaneously measure 64-channel broad fluorescence spectra (370-710 nm) of atmospheric aerosols at an excitation wavelength of 355 nm.
View Article and Find Full Text PDFSoft Matter
March 2025
Department of Chemistry "Ugo Schiff" and CSGI, University of Florence, via della Lastruccia 3, Sesto Fiorentino, Florence, Italy.
Polyurethanes are largely employed in various fields such as building, insulation and adhesive industries, but there is the constant need to develop sustainable formulations using "green" components and feasible processes. Here, a new series of sustainable castor oil and epoxidized castor oil-based (CO/EpCO) polyurethane networks was synthetized and characterized. The added epoxy functions react with isocyanates forming oxazolidinone linkages in the gels' network, reducing the gelation time from over 3 hours up to 0.
View Article and Find Full Text PDFFront Microbiol
February 2025
State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, Lanzhou University, Lanzhou, China.
Introduction: Arbuscular mycorrhizal (AM) fungi play a crucial role in maintaining diversity and ensuring the proper functioning of grassland ecosystems. A comprehensive understanding of the diversity, distribution patterns, and drivers of AM fungi in different habitats is essential for exploring the ecological roles in grassland ecosystems.
Methods: In this study, we utilized high-throughput sequencing technology to explore the diversity of AM fungi and their distribution at an altitude of approximately 3,500 m in the alpine grassland of the eastern Tibetan Plateau.
Climate-smart agricultural (CSA) practices have been adopted in various agroecological zones in Ethiopia to enhance productivity, improve resilience to climate change, and reduce greenhouse gas emissions through carbon sequestration. However, the overall impact of different CSA practices on productivity, adaptation, and mitigation metrics has not been exhaustively evaluated. The study employed a meta-analysis approach based on data from 220 peer-reviewed articles to assess the effects of commonly used CSA practices on these indicators across Ethiopia's diverse agroecological regions.
View Article and Find Full Text PDFOrg Lett
March 2025
Institute of Next Generation Matter Transformation, College of Material Sciences Engineering, Huaqiao University, Xiamen, Fujian 361021, China.
An expedient synthesis of α-aminoboronic acid derivatives via cobalt-catalyzed remote site-selective hydroboration of unactivated alkenes is described herein. The strategy is characterized by its simplicity, site-selectivity, and wide substrate scope, as both terminal and internal alkenes could undergo the reaction smoothly, affording the corresponding products in good yields. According to the mechanism, Co-H is generated from Co(acac) in the presence of HBpin, which starts the chain-walking strategy via a series of alkene insertion and β-H elimination process.
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