Post-calcination as an effective approach to enhance adsorption of arsenic and antimony anions by Mg/Al layered double hydroxide-decorated spent coffee ground biochars: Role of charge properties and active sites
{"title":"Post-calcination as an effective approach to enhance adsorption of arsenic and antimony anions by Mg/Al layered double hydroxide-decorated spent coffee ground biochars: Role of charge properties and active sites","authors":"","doi":"10.1016/j.envpol.2024.124850","DOIUrl":null,"url":null,"abstract":"<div><p>This study evaluated the effects of post-calcination on the charge properties and active sites of Mg/Al layered double hydroxide-decorated spent coffee ground biochars (LDH<sub>MgAl</sub>@SCGB) governing adsorption behaviors and mechanisms of arsenic (As<sup>V</sup>) and antimony (Sb<sup>V</sup>) anions from aqueous phases. Post-calcinated LDH<sub>MgAl</sub>@SCGB (PLDH<sub>MgAl</sub>@SCGB) exhibited higher adsorption capacities for As<sup>V</sup> and Sb<sup>V</sup> compared to spent coffee ground biochars (SCGB) and LDH<sub>MgAl</sub>@SCGB as post-calcination of LDH<sub>MgAl</sub>@SCGB enhanced the charge properties (surface zeta potential at pH 7.0: SCGB = −21.8 mV, LDH<sub>MgAl</sub>@SCGB = 28.5 mV, and PLDH<sub>MgAl</sub>@SCGB = 34.4 mV) and increased active sites by eliminating the anions (i.e., Cl<sup>−</sup> ions) and water molecules at its interlayers. The calculated kinetic, intra-particle diffusion, and isotherm parameters indicated that the chemisorption and intra-particle diffusion were mainly responsible for the adsorption of As<sup>V</sup> and Sb<sup>V</sup> by SCGB, LDH<sub>MgAl</sub>@SCGB, and PLDH<sub>MgAl</sub>@SCGB. Moreover, post-calcination of LDH<sub>MgAl</sub>@SCGB enhanced its selectivity toward As<sup>V</sup> and Sb<sup>V</sup> by reinforcing the electrostatic surface complexation via its improvement of charge properties. Since PLDH<sub>MgAl</sub>@SCGB exhibited the excellent reusability for the adsorption of As<sup>V</sup> (reuse efficiency >63.6%) and Sb<sup>V</sup> (reuse efficiency >52.1%), it can be concluded that post-calcination of LDH<sub>MgAl</sub>@SCGB is a promising method for improving the adsorption capacities for As<sup>V</sup> and Sb<sup>V</sup> in real water matrices.</p></div>","PeriodicalId":311,"journal":{"name":"Environmental Pollution","volume":null,"pages":null},"PeriodicalIF":7.6000,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Environmental Pollution","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0269749124015641","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
This study evaluated the effects of post-calcination on the charge properties and active sites of Mg/Al layered double hydroxide-decorated spent coffee ground biochars (LDHMgAl@SCGB) governing adsorption behaviors and mechanisms of arsenic (AsV) and antimony (SbV) anions from aqueous phases. Post-calcinated LDHMgAl@SCGB (PLDHMgAl@SCGB) exhibited higher adsorption capacities for AsV and SbV compared to spent coffee ground biochars (SCGB) and LDHMgAl@SCGB as post-calcination of LDHMgAl@SCGB enhanced the charge properties (surface zeta potential at pH 7.0: SCGB = −21.8 mV, LDHMgAl@SCGB = 28.5 mV, and PLDHMgAl@SCGB = 34.4 mV) and increased active sites by eliminating the anions (i.e., Cl− ions) and water molecules at its interlayers. The calculated kinetic, intra-particle diffusion, and isotherm parameters indicated that the chemisorption and intra-particle diffusion were mainly responsible for the adsorption of AsV and SbV by SCGB, LDHMgAl@SCGB, and PLDHMgAl@SCGB. Moreover, post-calcination of LDHMgAl@SCGB enhanced its selectivity toward AsV and SbV by reinforcing the electrostatic surface complexation via its improvement of charge properties. Since PLDHMgAl@SCGB exhibited the excellent reusability for the adsorption of AsV (reuse efficiency >63.6%) and SbV (reuse efficiency >52.1%), it can be concluded that post-calcination of LDHMgAl@SCGB is a promising method for improving the adsorption capacities for AsV and SbV in real water matrices.
期刊介绍:
Environmental Pollution is an international peer-reviewed journal that publishes high-quality research papers and review articles covering all aspects of environmental pollution and its impacts on ecosystems and human health.
Subject areas include, but are not limited to:
• Sources and occurrences of pollutants that are clearly defined and measured in environmental compartments, food and food-related items, and human bodies;
• Interlinks between contaminant exposure and biological, ecological, and human health effects, including those of climate change;
• Contaminants of emerging concerns (including but not limited to antibiotic resistant microorganisms or genes, microplastics/nanoplastics, electronic wastes, light, and noise) and/or their biological, ecological, or human health effects;
• Laboratory and field studies on the remediation/mitigation of environmental pollution via new techniques and with clear links to biological, ecological, or human health effects;
• Modeling of pollution processes, patterns, or trends that is of clear environmental and/or human health interest;
• New techniques that measure and examine environmental occurrences, transport, behavior, and effects of pollutants within the environment or the laboratory, provided that they can be clearly used to address problems within regional or global environmental compartments.