The relative influences of hydrologic processes and biogeochemistry on the transport and retention of minor solutes were compared in the riverbed of the lower Merced River (California, USA). The subsurface of this reach receives ground water discharge and surface water infiltration due to an altered hydraulic setting resulting from agricultural irrigation. Filtered ground water samples were collected from 30 drive point locations in March, June, and October 2004. Hydrologic processes, described previously, were verified by observations of bromine concentrations; manganese was used to indicate redox conditions. The separate responses of the minor solutes strontium, barium, uranium, and phosphorus to these influences were examined. Correlation and principal component analyses indicate that hydrologic processes dominate the distribution of trace elements in the ground water. Redox conditions appear to be independent of hydrologic processes and account for most of the remaining data variability. With some variability, major processes are consistent in two sampling transects separated by 100 m.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.2134/jeq2008.0448 | DOI Listing |
Environ Res
January 2025
Science and Technology Innovation Center of Smart Water and Resource Environment, Northeastern University, Shenyang 110819, China; School of Resources and Civil Engineering, Northeastern University, Shenyang 110819, China; Liaoning Institute of Technological Innovation in Solid Waste Utilization, Northeastern University, Shenyang 110819, China.
The preparation of low-carbon cementitious materials through the synergistic coupling of multiple solid wastes has great potential for development, which can improve the problems of resource shortage and environmental pollution. In this paper, a new type of supersulfated cement was developed by using calcium carbide residue (CCR) as an alkaline activator. The effects of CCR content on the mechanical properties and hydration behaviors of the samples under steam curing conditions were discussed.
View Article and Find Full Text PDFEnviron Res
January 2025
Key Laboratory of Regional Environment and Eco-restoration, Ministry of Education, Shenyang University, Shenyang, 110044, Liaoning, China. Electronic address:
Nano-microplastics and 17β-E2 have been frequently detected as emerging high-concern pollutants in aquatic systems, and their interaction at the solid/liquid interface has become a research focus in environmental studies. The interfacial sorption kinetics and equilibrium characteristics of 17β-estradiol (17β-E2) on nano-polystyrene (Nano-PS) with different particle sizes and organic functional group modifications were systematically investigated in aqueous environments in this study. The interfacial interaction mechanism between Nano-PS particles and 17β-E2 was elucidated by utilizing SEM, FTIR, XPS and BET techniques.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Department of Environmental Engineering, Korea National University of Transportation, Chungju, 27469, Republic of Korea. Electronic address:
This study investigates the use of nano-sized oxygen bubbles (NOBs) to enhance BTEX (benzene, toluene, ethylbenzene, xylene) biodegradation in groundwater. Optimized NOBs, averaging 155 nm and at a concentration of 6.59 × 10⁸ bubbles/mL, were found to provide sustained oxygen release with a half-life of approximately 50 days.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Hubei Subsurface Multi-scale Imaging Key Laboratory, School of Geophysics and Geomatics, China University of Geosciences, Wuhan, China.
Groundwater plays a key role in the water cycle and is used to meet industrial, agricultural, and domestic water demands. High-resolution modeling of groundwater storage is often challenging due to the limitations of observation techniques and mathematical methods. In this study, two machine learning (ML) algorithms, namely random forest (RF) and artificial neural networks (ANNs), were employed to estimate groundwater level anomaly (GWLA) and groundwater storage anomaly (GWSA) with a 0.
View Article and Find Full Text PDFJ Contam Hydrol
January 2025
Mines Paris, PSL University, Center for Geosciences and Geoengineering, France; ORANO Mining, Environmental R&D Dpt., France.
Sandstone-hosted uranium is mined in the Sahel regions of Niger. The Teloua aquifer is located beneath the ore-processing facilities of one such former mine, COMINAK. The pores of the sandstone bedrock are partially filled by tosudite, a clay with sorption capacities.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!