Modeling three-dimensional contaminant transport released from arbitrary shape source geometries is useful in hydrological and environmental sciences. This article produces several analytical solutions for three-dimensional contaminant transport in a homogeneous and isotropic aquifer by using Green's function with the groundwater flow which is assumed to be in three directions. The solutions are obtained for both finite depth aquifer and semi-infinite depth aquifer. Various types of sources are discussed: point, line, plane, or cuboid sources. The continuous and instantaneous sources are also investigated. A MATLAB coding is developed to calculate the numerical integrals which occur at the solutions. Some solutions are verified with the solutions obtained in the literature. This study confirms the effect of groundwater velocities in all directions on the degree and the directions of contaminant spreading. Additionally, the results highlight the significant effect of the geometrical shape of the contaminant sources on contaminant concentrations for instantaneous and continuous sources. In particular, the cuboid source and the horizontal rectangular source provide the highest concentrations. The analytical solutions developed in this article can be applied for a wide range of contaminant transport.
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http://dx.doi.org/10.1007/s11356-022-21402-8 | DOI Listing |
Carbohydr Polym
March 2025
School of Environmental and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China. Electronic address:
Carbon dots (CDs) mediated g-CN (CN) is a promising visible-light-driven semiconductor in catalyzing peroxymonosulfate (PMS) for aqueous contaminants remediation. However, the poor dispersibility of powered catalyst and its challenging recyclability impede their broader application. Herein, we embedded FeN bridge within the g-CN framework and immobilized g-CN gel beads (CA/FNCCN) through a 3D cross-linking process with sodium alginate.
View Article and Find Full Text PDFPlacenta
December 2024
Johns Hopkins University Bloomberg School of Public Health, USA. Electronic address:
Chronic arsenic exposure affects over 140 million people globally. While arsenic easily crosses the placenta, the specific mechanisms impacting placental immune cell populations and fetal health are unclear. Maternal arsenic exposure is epidemiologically linked to increased infection risk, mortality, and cancer susceptibility in offspring, emphasizing the importance of understanding placentally-mediated immune effects.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, PR China.
The efficient removal of organic contaminants from high-salinity wastewater is crucial for resource recovery and achieving zero discharge. Nanofiltration (NF) membranes are effective in separating organic compounds and monovalent salts, but they typically exhibit an excessive rejection of divalent salts. Modifying the charge characteristics of NF membranes can improve salt permeation; however, the role of charge spatial distribution in governing salt transport behavior is not fully understood.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
Rice (), a globally significant staple crop, is crucial for ensuring human food security due to its high yield and quality. However, the intensification of industrial activities has resulted in escalating cadmium (Cd) pollution in agricultural soils, posing a substantial threat to rice production. To address this challenge, this review comprehensively analyzes rice promoters, with a particular focus on identifying and characterizing key -regulatory elements (CREs) within them.
View Article and Find Full Text PDFCells
December 2024
Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee 247667, India.
The quest for cleaner and sustainable energy sources is crucial, considering the current scenario of a steep rise in energy consumption and the fuel crisis, exacerbated by diminishing fossil fuel reserves and rising pollutants. In particular, the bioaccumulation of hazardous substances like trivalent chromium has not only disrupted the fragile equilibrium of the ecological system but also poses significant health hazards to humans. Microalgae emerged as a promising solution for achieving sustainability due to their ability to remediate contaminants and produce greener alternatives such as biofuels.
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