We investigated the role of natural organic matter in cadmium mobility in soil environments. We collected the dissolved organic matter from two different types of natural waters: pond surface water, which is oxic, and deep anoxic groundwater. The collected organic matter was fractionated into four groups with molecular weights (unit: Da (Daltons)) of <1 x 10(3), 1-10 x 10(3), 10-100 x 10(3), and >100 x 10(3). The organic matter source was land plants, based on the carbon isotope ratios (delta(13)C/(12)C). The organic matter in surface water originated from presently growing land plants, based on (14)C dating, but the organic matter in deep groundwater originated from land plants that grew approximately 4000 years ago. However, some carbon was supplied by the high-molecular-weight fraction of humic substances in soil or sediments. Cadmium interacted in a system of siliceous sand, fractionated organic matter, and water. The lowest molecular weight fraction of organic matter (<1 x 10(3)) bound more cadmium than did the higher molecular weight fractions. Organic matter in deep groundwater was more strongly bound to cadmium than was organic matter in surface water. The binding behaviours of organic matter with cadmium depended on concentration, age, molecular weight, and degradation conditions of the organic matter in natural waters. Consequently, the dissolved, low-molecular-weight fraction in organic matter strongly influences cadmium migration and mobility in the environment.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.scitotenv.2007.08.002 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Effects of Low-Severity Fire on the Composition and Stability of Soil Organic Carbon in Permafrost Peatlands (Northeast China).
Environ Sci Technol
January 2025
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Shengbei Street 4888, Changchun 130102, China.
Climate change and human activity are increasing the frequency of wildfires in peatlands and threatening permafrost peatland carbon pools. In Northeast China, low-severity prescribed fires are conducted annually on permafrost peatlands to reduce the risk of wildfires. These fires typically do not burn surface peat but lead to the loss of surface vegetation and introduction of pyrogenic carbon.
View Article and Find Full Text PDFElectron Microscopy Reveals Inhomogeneous Adsorption of Iodine and Concurrent Defect Formation in a Metal-Organic Framework.
J Am Chem Soc
January 2025
Center for Electron Microscopy, South China University of Technology, Guangzhou 511436, China.
Adsorption behaviors are typically examined through adsorption isotherms, which measure the average adsorption amount as a function of partial pressure or time. However, this method is incapable of identifying inhomogeneities across the adsorbent, which may occur in the presence of strong intermolecular interactions of the adsorbate. In this study, we visualize the adsorption of molecular iodine (I) in the metal-organic framework material MFM-300(Sc) using high-resolution scanning transmission electron microscopy (STEM).
View Article and Find Full Text PDFRegulating Charge Distribution in Porphyrin-Based Polymer for Achieving Photocatalytic CO Conversion to CH or CH.
Small
January 2025
School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
The photocatalytic conversion of CO into products such as CH and CH poses a significant challenge due to the lengthy reaction steps and the high energy barrier involved. In this study, both benzothiadiazole (BTD) and hydroxyl groups (-OH) are introduced into cobalt-based polymerized porphyrinic network (PPN) through a C-C coupling reaction. This modification of orbital energy levels that strengthens the ability of gain electrons and facilitates the charge transfer in PPN.
View Article and Find Full Text PDFExploring the Molecular Composition of Dissolved Organic Matter and Its Connection to Microbial Communities in Industrial-Scale Anaerobic Digestion of Chicken Manure.
Toxics
January 2025
School of Computer Science and Hubei Key Laboratory of Intelligent Geo-Information Processing, China University of Geosciences, Wuhan 430078, China.
Anaerobic digestion (AD) technology offers significant advantages in addressing environmental issues arising from the intensification of livestock production since it enables waste reduction and energy recovery. However, the molecular composition of dissolved organic matter (DOM) and its linkages to microbial biodiversity during the industrial-scale AD process of chicken manure (CM) remains unclear. In this study, the chemical structure of CM digestate-derived DOM was characterized by using multi-spectroscopic techniques and ultrahigh-resolution mass spectrometry, and the microbial composition was detected by using 16S rRNA gene sequencing.
View Article and Find Full Text PDFAssessment of Organic Matter Influence on the Ecological Integrity of Poyang Lake Using O/E Model and Chemical-Biological Indices over the Past Two Decades.
Toxics
December 2024
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Ecological integrity, encompassing physical, chemical, and biological aspects, is crucial for sustaining ecosystem service functions and stability. As the largest freshwater lake in China, the ecological integrity of Poyang Lake has attracted much attention due to the over-exploitation of its water resources in recent years. In this study, several biological and water quality surveys on water ecological conditions were carried out at 11 sampling points of Poyang Lake from 1998 to 2022, and the ecological health of Poyang Lake was evaluated by use of the O/E (Observation/Expectation) model and the chemical-biological index method according to the status of the water quality and the structure of the benthic fauna in the four seasons, respectively.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!