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Yasmin Vieira Matias Schadeck Netto Éder C.Lima Ioannis Anastopoulos Marcos L.S.Oliveira Guilherme L.Dotto 《地学前缘(英文版)》2022,(1):457-477
Adsorption is a unit operation widely used for the tertiary treatment of the most diverse effluents,whose mechanism is based on removing recalcitrant compounds from the organic and inorganic origin.In this process,choosing a suitable adsorbent is a fundamental point.This review article focuses on the adsorbents with natural geological origin:minerals,clays,geopolymers,and even wastes resulted from mining activity.Therefore,over 450 articles and research papers were explored.These materials’main sources are described,and their characteristics,composition,and intrinsic properties are related to adsorption.Herein,we discuss the effects of several process parameters,such as p H,temperature,pollutant,and adsorbent concentration.Furthermore,equilibrium,kinetics,and thermodynamic aspects are also addressed,and relevant regeneration prospects and final disposal.Finally,some suggestions and perspectives on applying these adsorbents in wastewater treatment are presented as future trends. 相似文献
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This work studied the influence of meteorological conditions on particulate polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of Higashi Hiroshima, Japan. The seasonal variation of particulate PAHs was also covered. It was found that ambient temperature, solar intensity and weekly rainfall had significant influence on the particulate PAH concentration based on correlation studies. Correlation of particulate PAHs with ambient temperature, solar intensity, weekly rainfall, wind speed and humidity was studied by using Pearson correlation analysis. Particulate PAHs had a strong negative correlation with ambient temperature and solar intensity. A moderate negative correlation with weekly rainfall was also observed. There was no significant correlation between particulate PAHs with wind speed as well as humidity. Besides, particulate PAHs were found to have significant positive correlation with sulfur dioxide and nitrogen dioxide while having a moderate negative correlation with ozone. The particulate PAHs in Higashi Hiroshima exerted distinct seasonal variation with a higher concentration in winter and lower concentration in summer. When compared among PAHs with different numbers of aromatic rings; 5-ring PAHs was found to exert the most distinct seasonal variation. The contribution of carcinogenic PAHs to total particulate PAH concentration was fairly constant at about 50% throughout the year. 相似文献
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An impact model of gravity designed to emulate Newton’s law of gravitation is applied to particles with relative motions at slow and relativistic speeds. Based on this model, a gravitational interaction mode is then conceived between photons and massive particles. This implies a deflection perpendicular to the propagation direction of a photon twice as large as expected from the mass-energy relation of photons—in accordance with observations and the General Theory of Relativity. The longitudinal interaction is compatible with the energy and momentum conservation principles applied to massless entities, and the results are consistent with the observed Shapiro delay. 相似文献
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Landscape evolution is governed by the interplay of uplift, climate, erosion, and the discontinuous pattern of sediment transfer from the proximal source of erosion to distal sedimentary sinks. The transfer of sediment through the catchment system is often referred to as a cascade, the pattern of which is modulated by the interaction of key network characteristics such as the distribution of transport capacity and resultant zones of sediment storage. An understanding of how sediment production is modulated through river networks with different topological structures at the associated timescales has remained elusive but presents significant implications for the knowledge of river response to disturbance events, and floodplain asset management. A multivariate method of identifying representative topological structures from a range of river networks is presented. Stream networks from 59 catchments in the South Island of New Zealand were extracted from a digital elevation model and their key topological parameters quantified. A principal component analysis was implemented to reduce these to two-dimensional axes that represent the magnitude of network branching and the topographic structure of each catchment, respectively. An agglomerative hierarchical clustering analysis revealed five network ‘types’, which are examined in terms of their internal structural characteristics and relationships to potential regional-scale controls. Implications for sediment transfer in these network ‘types’, and their use as representative networks for further analysis, are discussed. © 2020 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd 相似文献
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A theoretical investigation has been made of electrostatic solitary structures in an electron-positron-ion (e-p-i) plasma, taking nonextensive electrons and nonextensive positrons. By employing the reductive perturbation method, the basic characteristics of ion-acoustic (IA) solitary waves (SWs) in a three-component e-p-i plasma (consisting of negatively charged nonextensive electrons, positively charged nonextensive positrons, and ions) have been addressed. The Korteweg-de Vries (K-dV), modified K-dV (mK-dV), and Gardner equations are derived and their numerical solutions are obtained. It has been shown that the combined effects of electron nonextensivity, positron nonextensivity, and ions significantly modify the behavior of these electrostatic solitary structures that have been found to exist with positive and negative potential in this plasma model. The present analysis may be useful to understand and demonstrate the dynamical properties of IA SWs in different astrophysical and cosmological scenarios (viz. stellar polytropes, hadronic matter and quark-gluon plasma, protoneutron stars, dark-matter halos, etc.). 相似文献