{"title":"用于油水混合物分离的酸碱活化蛭石有机粘土","authors":"Faezeh Hajizadeh , Reza Norouzbeigi , Elmira Velayi","doi":"10.1016/j.clay.2024.107600","DOIUrl":null,"url":null,"abstract":"<div><div>Oily wastewater discharge causes severe environmental pollution and resource waste, requiring the development of low-cost adsorbents with good hydrophobicity. This study presents the preparation and use of a novel highly hydrophobic adsorbent based on natural vermiculite clay minerals to separate free/emulsified oil-water mixtures. Vermiculite was first activated with sulfuric acid and potassium hydroxide to increase its adsorption capacity and surface area. The sample was then modified with cetyltrimethylammonium bromide (CTAB) to change the wetting properties from hydrophilic to hydrophobic and increase oil adsorption. XRD, XRF, FESEM, BET, FTIR, and zeta potential analyses were carried out to determine changes in texture, morphology, and chemical composition of vermiculite affected by acid, base and acid-base activation. According to the results, the acid-base activation process was selected for vermiculite treatment before CTAB modification, which demonstrated a high oil adsorption selectivity (1910.6 %) compared to raw vermiculite (44.14 %). Effect of CTAB concentration on vermiculite's wetting properties was studied. The results confirmed that the acid-base activated sample modified at 0.9 mmol.L<sup>−1</sup> near the critical micelle concentration of CTAB exhibited highly hydrophobic properties (water contact angle of 148° ± 1°). For oil-in-water emulsions, the treated adsorbent demonstrated a high oil removal efficiency of 96 ± 2 %. Additionally, a packed layer of highly hydrophobic vermiculite was applied for free heavy/light oil-water mixture and water-in-oil emulsion separation. The performance test for separation of free oil-water mixture and water-in-oil emulsion showed high separation efficiency (all above 90 %). The reusability of highly hydrophobic vermiculite as well as the effect of oil type, the thickness of the adsorbent layer, and the height of the water phase on separation performance were also investigated.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"262 ","pages":"Article 107600"},"PeriodicalIF":5.3000,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Organoclays from acid-base activated vermiculites for oil-water mixture separations\",\"authors\":\"Faezeh Hajizadeh , Reza Norouzbeigi , Elmira Velayi\",\"doi\":\"10.1016/j.clay.2024.107600\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Oily wastewater discharge causes severe environmental pollution and resource waste, requiring the development of low-cost adsorbents with good hydrophobicity. This study presents the preparation and use of a novel highly hydrophobic adsorbent based on natural vermiculite clay minerals to separate free/emulsified oil-water mixtures. Vermiculite was first activated with sulfuric acid and potassium hydroxide to increase its adsorption capacity and surface area. The sample was then modified with cetyltrimethylammonium bromide (CTAB) to change the wetting properties from hydrophilic to hydrophobic and increase oil adsorption. XRD, XRF, FESEM, BET, FTIR, and zeta potential analyses were carried out to determine changes in texture, morphology, and chemical composition of vermiculite affected by acid, base and acid-base activation. According to the results, the acid-base activation process was selected for vermiculite treatment before CTAB modification, which demonstrated a high oil adsorption selectivity (1910.6 %) compared to raw vermiculite (44.14 %). Effect of CTAB concentration on vermiculite's wetting properties was studied. The results confirmed that the acid-base activated sample modified at 0.9 mmol.L<sup>−1</sup> near the critical micelle concentration of CTAB exhibited highly hydrophobic properties (water contact angle of 148° ± 1°). For oil-in-water emulsions, the treated adsorbent demonstrated a high oil removal efficiency of 96 ± 2 %. Additionally, a packed layer of highly hydrophobic vermiculite was applied for free heavy/light oil-water mixture and water-in-oil emulsion separation. The performance test for separation of free oil-water mixture and water-in-oil emulsion showed high separation efficiency (all above 90 %). The reusability of highly hydrophobic vermiculite as well as the effect of oil type, the thickness of the adsorbent layer, and the height of the water phase on separation performance were also investigated.</div></div>\",\"PeriodicalId\":245,\"journal\":{\"name\":\"Applied Clay Science\",\"volume\":\"262 \",\"pages\":\"Article 107600\"},\"PeriodicalIF\":5.3000,\"publicationDate\":\"2024-10-21\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Applied Clay Science\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S016913172400348X\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Clay Science","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S016913172400348X","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Organoclays from acid-base activated vermiculites for oil-water mixture separations
Oily wastewater discharge causes severe environmental pollution and resource waste, requiring the development of low-cost adsorbents with good hydrophobicity. This study presents the preparation and use of a novel highly hydrophobic adsorbent based on natural vermiculite clay minerals to separate free/emulsified oil-water mixtures. Vermiculite was first activated with sulfuric acid and potassium hydroxide to increase its adsorption capacity and surface area. The sample was then modified with cetyltrimethylammonium bromide (CTAB) to change the wetting properties from hydrophilic to hydrophobic and increase oil adsorption. XRD, XRF, FESEM, BET, FTIR, and zeta potential analyses were carried out to determine changes in texture, morphology, and chemical composition of vermiculite affected by acid, base and acid-base activation. According to the results, the acid-base activation process was selected for vermiculite treatment before CTAB modification, which demonstrated a high oil adsorption selectivity (1910.6 %) compared to raw vermiculite (44.14 %). Effect of CTAB concentration on vermiculite's wetting properties was studied. The results confirmed that the acid-base activated sample modified at 0.9 mmol.L−1 near the critical micelle concentration of CTAB exhibited highly hydrophobic properties (water contact angle of 148° ± 1°). For oil-in-water emulsions, the treated adsorbent demonstrated a high oil removal efficiency of 96 ± 2 %. Additionally, a packed layer of highly hydrophobic vermiculite was applied for free heavy/light oil-water mixture and water-in-oil emulsion separation. The performance test for separation of free oil-water mixture and water-in-oil emulsion showed high separation efficiency (all above 90 %). The reusability of highly hydrophobic vermiculite as well as the effect of oil type, the thickness of the adsorbent layer, and the height of the water phase on separation performance were also investigated.
期刊介绍:
Applied Clay Science aims to be an international journal attracting high quality scientific papers on clays and clay minerals, including research papers, reviews, and technical notes. The journal covers typical subjects of Fundamental and Applied Clay Science such as:
• Synthesis and purification
• Structural, crystallographic and mineralogical properties of clays and clay minerals
• Thermal properties of clays and clay minerals
• Physico-chemical properties including i) surface and interface properties; ii) thermodynamic properties; iii) mechanical properties
• Interaction with water, with polar and apolar molecules
• Colloidal properties and rheology
• Adsorption, Intercalation, Ionic exchange
• Genesis and deposits of clay minerals
• Geology and geochemistry of clays
• Modification of clays and clay minerals properties by thermal and physical treatments
• Modification by chemical treatments with organic and inorganic molecules(organoclays, pillared clays)
• Modification by biological microorganisms. etc...