Characteristics of soil organic matter (SOM) are important, especially in the Amazon region, which represents one of the world's most relevant carbon reservoirs. In this work, the concentrations of carbon and differences in its composition (humification indexes) were evaluated and compared for several horizons (0 to 390cm) of three typical Amazonian podzol profiles. Fluorescence spectroscopy was used to investigate the humic acid (HA) fractions of SOM isolated from the different samples. Simple and labile carbon structures appeared to be accumulated in surface horizons, while more complex humified compounds were leached and accumulated in intermediate and deeper Bh horizons. The results suggested that the humic acids originated from lignin and its derivatives, and that lignin could accumulate in some Bh horizons. The HA present in deeper Bh horizons appeared to originate from different formation pathways, since these horizons showed different compositions. There were significant compositional changes of HA with depth, with four types of organic matter: recalcitrant, humified, and old dating; labile and young dating; humified and young dating; and little humified and old dating. Therefore, the humification process had no direct relation with the age of the organic matter in the Amazonian podzols.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.scitotenv.2017.09.068 | DOI Listing |
Adv Sci (Weinh)
January 2025
Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan.
A highly electron-rich S,N heteroacene building block is developed and condensed with FIC and Cl-IC acceptors to furnish CT-F and CT-Cl, which exhibit near-infrared (NIR) absorption beyond 1000 nm. The C-shaped CT-F and CT-Cl self-assemble into a highly ordered 3D intermolecular packing network via multiple π-π interactions in the single crystal structures. The CT-F-based organic photovoltaic (OPV) achieved an impressive efficiency of 14.
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).
J Environ Manage
January 2025
College of Resources and environmental Sciences, Gansu Agricultural University, Lanzhou, 730070, China. Electronic address:
Limestone mining in arid regions, particularly within fragile environments, leads to severe environmental pollution and ecological degradation. Developing a scientifically sound and effective ecological rehabilitation strategy is therefore critical. This study constructed a three-dimensional ecological rehabilitation model integrating soil amelioration and vegetation reconstruction.
View Article and Find Full Text PDFEnviron Res
January 2025
Departamento de Bioloxía Vexetal e Ciencias do Solo, Área de Edafoloxía e Química Agrícola, Facultade de Ciencias, Universidade de Vigo, As Lagoas s/n, Ourense, 32004, Spain; Instituto de Agroecoloxía e Alimentación (IAA), Campus Auga, Universidade de Vigo, Ourense, 32004, Spain; Comunidades Microbianas de suelos (id. UA 1678), MBG-CSIC/ Universidad de Vigo, Unidad asociada al CSIC, Spain.
The overuse of pesticides in agriculture has led to widespread pollution of soils and water resources, becoming a problem of great concern. Nowadays, special attention is given to neonicotinoids, particularly acetamiprid, the only neonicotinoid insecticide allowed for outdoor use in the European Union. Once acetamiprid reaches the soil, adsorption/desorption is the main process determining its bioavailability and environmental fate.
View Article and Find Full Text PDFTalanta
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 PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!