Natural attenuation (NA) is of great significance for the remediation of contaminated groundwater, and how to identify NA patterns of toluene in aquifers more quickly and effectively poses an urgent challenge. In this study, the NA of toluene in two typical soils was conducted by means of soil column experiment. Based on column experiments, dissolved organic matter (DOM) was rapidly identified using fluorescence spectroscopy, and the relationship between DOM and the NA of toluene was established through structural equation modeling analysis. The adsorption rates of toluene in clay and sandy soil were 39 % and 26 %, respectively. The adsorption capacity and total NA capacity of silty clay were large. The occurrence of fluorescence peaks of protein-like components and specific products indicated the occurrence of biodegradation. Arenimonas, Acidovorax and Brevundimonas were the main degrading bacteria identified in Column A, while Pseudomonas, Azotobacter and Mycobacterium were the main ones identified in Column B. The pH, ORP, and Fe(II) were the most important factors affecting the composition of microbial communities, which in turn affected the NA of toluene. These results provide a new way to quickly identify NA of toluene.
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http://dx.doi.org/10.1016/j.jhazmat.2024.134952 | DOI Listing |
Environ Sci Process Impacts
January 2025
Department of Environmental Science, Stockholm University, Sweden.
In surface waters, photodegradation is a major abiotic removal pathway of the neurotoxin monomethylmercury (MMHg), acting as a key control on the amounts of MMHg available for biological uptake. Different environmental factors can alter the rate of MMHg photodegradation. However, our understanding of how MMHg photodegradation pathways in complex matrixes along the land-to-ocean aquatic continuum respond to changes in salinity, dissolved organic carbon (DOC) concentration and dissolved organic matter (DOM) composition is incomplete.
View Article and Find Full Text PDFRapid Commun Mass Spectrom
April 2025
Department of Civil and Environmental Engineering, Syracuse University, Syracuse, New York, USA.
Rationale: The complexation with dissolved organic matter (DOM) is a pivotal factor influencing transformations, transport, and bioavailability of mercury (Hg) in aquatic environments. However, identifying these complexes poses a significant challenge because of their low concentrations and the presence of coexisting ions.
Methods: In this study, mercury-dissolved organic matter (Hg-DOM) complexes were isolated through solid-phase extraction (SPE) from Hg-humic acid suspensions, and complexes were putatively identified using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS).
Recent Pat Nanotechnol
January 2025
Raj Kumar Goel Institute of Technology (Pharmacy), 5-Km. Stone, Delhi-Meerut Road, Ghaziabad, Uttar Pradesh, India.
Background: Nanosuspension has emerged as an effective, lucrative, and unequalled approach for efficiently elevating the dissolution and bioavailability of aqueous soluble drugs. Diverse challenges persist within this domain, demanding further comprehensive investigation and exploration.
Objective: This study aims to design, develop, optimise formulation and process variables, and characterise the stabilised aqueous dissolvable nanosuspension using chlorthalidone as a BCS class- IV drug.
Talanta
January 2025
DCU Water Institute, School of Chemical Sciences, Dublin City University, Ireland. Electronic address:
Anthropogenic activities have led to increased stress on our marine and other aquatic environments. There is a pressing need to monitor, measure, understand and mitigate causes of these pressures. This paper presents a novel optical head for monitoring and measuring marine based optical phenomena.
View Article and Find Full Text PDFChem Sci
January 2025
Department of Chemistry, Rice University Houston Texas 77005 USA
We recently demonstrated molecular plasmons in cyanine dyes for the conversion of photon energy into mechanical energy through a whole-molecule coherent vibronic-driven-action. Here we present a model, a molecular plasmon analogue of molecular orbital theory and of plasmon hybridization in metal nanostructures. This model describes that molecular plasmons can be obtained from the combination or hybridization of elementary molecular fragments, resulting in molecules with hybridized plasmon resonances in the electromagnetic spectrum.
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