Calculating how long a coupled multispecies reactive-diffusive transport process in a heterogeneous medium takes to effectively reach steady state is important in many applications. In this paper, we show how the time required for such processes to transition to within a small specified tolerance of steady state can be calculated accurately without having to solve the governing time-dependent model equations. Our approach is valid for general first-order reaction networks and an arbitrary number of species. Three numerical examples are presented to confirm the analysis and investigate the efficacy of the approach. A key finding is that for sequential reactions our approach works better provided the two smallest reaction rates are well separated.
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http://dx.doi.org/10.1103/PhysRevE.102.012107 | DOI Listing |
Nat Commun
January 2025
Department of Environment, Zhejiang University of Technology, Hangzhou, 310014, China.
The generation of radicals through photo-Fenton-like reactions demonstrates significant potential for remediating emerging organic contaminants (EOCs) in complex aqueous environments. However, the excitonic effect, induced by Coulomb interactions between photoexcited electrons and holes, reduces carrier utilization efficiency in these systems. In this study, we develop Cu single-atom-loaded covalent organic frameworks (Cu/COFs) as models to modulate excitonic effects.
View Article and Find Full Text PDFSci Total Environ
January 2025
Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China; Guangdong Basic Research Center of Excellence for Ecological Security and Green Development, Guangzhou, 510000, China.
OH-mediated advanced oxidation processes (AOPs) are widely used in wastewater treatment and drinking water purification. Recently, an increasing number of studies have indicated that common inorganic nitrogen ions can efficiently generate •OH under UV irradiation, demonstrating strong performance in the degradation of various contaminants. Conversely, the presence of inorganic nitrogen ions in UV or other oxidation processes dramatically increases the yield of toxic nitro (so)-aromatic products and the formation potential of nitrogenous disinfection by-products with high genotoxicity and cytotoxicity.
View Article and Find Full Text PDFSci Rep
January 2025
UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria, South Africa.
This research successfully synthesized semiconductive magnesioferrite (MgFeO) nanomaterials using a green chemistry method that utilizes the natural extract of Moringa olefeira serving as both a reducing and oxidizing agent. The optical characteristics and crystalline structure of the MgFeO nanomaterials were analysed using photoluminescence, diffuse reflectance spectroscopy, and X-ray diffraction. Additionally, Fourier transform infrared spectroscopy provided valuable insights into the chemical bonding and composition.
View Article and Find Full Text PDFBioresour Technol
January 2025
School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, China; Henan Center for Outstanding Overseas Scientists, Zhengzhou 450001, China. Electronic address:
Achieving the efficient biomass alcoholysis to methyl levulinate (ML) under high solid content conditions and establishing its kinetic model are crucial, but remain challenging. Here, the alcoholysis of microcrystalline cellulose (MC) and xylose residue (XR) to ML under high solid content conditions using CuSO as a catalyst was reported. High yield (34.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul 04620, Republic of Korea. Electronic address:
The presence of cobalt ions (Co) and radionuclides (Co) in industrial and radioactive effluents pose serious threats to environmental ecosystems and human health. This paper presents the synthesis of dual-functional hydroxyapatite (HAp)-incorporated spherical carbon (SC) composite (HAp/SC) towards the selective adsorption of cobalt from wastewater and the utilization of the Co-adsorbed HAp/SC composite (Co- HAp/SC) as an electrocatalyst for the oxygen evolution reaction (OER). Herein, we prepared a series of HAp/SC composites by varying HAp weight percentages of 10 %, 20 %, 30 %, 40 %, and 50 %.
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