Separation Science and Technology最新文献

{"title":"Study of plutonium recovery from acidic feed using polyethersulfone encapsulating TBP, DEHPA, and mixture of TBP and DEHPA beads","authors":"Satya Ranjan Guchhait, Kankan Patra, Kartikey K. Yadav, D.K. Singh, Arijit Sengupta, T. P. Valsala, D.B. Sathe, R.B. Bhatt","doi":"10.1080/01496395.2023.2266562","DOIUrl":"https://doi.org/10.1080/01496395.2023.2266562","url":null,"abstract":"ABSTRACTPolyethersulfone (PES) composite beads encapsulating the extractants di-(2-ethylhexyl) phosphoric acid (DEHPA), tributyl phosphoric acid (TBP), and mixture of DEHPA & TBP were synthesized. The synthesis was carried out using phase inversion method. Subsequently, these PES beads were applied for the recovery of plutonium [Pu (IV)] from different aqueous acidic medium. In kinetic studies, the extraction of Pu (IV) was found to be fast and equilibrium was attained within 5 minutes. In batch sorption studies, the role of aqueous acidity and nitrate ion concentration on extraction efficiency was evaluated. Also, the effects of variation of acid medium, concentration of metal ion, extractant concentration were examined for Pu (IV) recovery. Back extraction was effectively carried out using oxalic acid. The reusability of the PES beads was tested for 10 extraction – stripping cycles.KEYWORDS: Polyethersulfone composite beadsDEHPATBPsorptiondesorptionnitric acidplutoniumsorption studies AcknowledgmentsAuthors acknowledge U. Dani, C.E, NRB, BARCDisclosure statementNo potential conflict of interest was reported by the author(s).","PeriodicalId":21680,"journal":{"name":"Separation Science and Technology","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135045891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selective removal and simultaneous immobilization of Pb cations from solutions","authors":"Yunchul Cho, Jing Wang, Sungpyo Kim, Huaibin Zhang, Wenyan Huang, Sridhar Komarneni","doi":"10.1080/01496395.2023.2262745","DOIUrl":"https://doi.org/10.1080/01496395.2023.2262745","url":null,"abstract":"ABSTRACTThe aim of this study was to develop a layered ammonium tin phosphate as a potential sorbent for removal of Pb2+ ions by exchange/sorption or other mechanism from contaminated solutions. A layered ammonium tin phosphate (NH4-SnP), δ-SnP – NH4 was synthesized using the hydrothermal process. XRD pattern of the NH4-SnP revealed that the final product obtained was δ-tin (IV) phosphate with the d(001)-spacing of about 14.8 Å containing ammonium ions and water molecules in the interlayers. In order to investigate the removal efficiency of Pb2+ cations by the NH4-SnP, batch-type of sorption experiments were carried out with 2 days of equilibration time at room temperature. Also, the kinetics of reaction was performed at room temperature to determine equilibrium time. The sorption isotherms for Pb2+ cations indicated that NH4-SnP showed high affinity for these ions with all the concentrations used. In addition, kinetic data showed preference for Pb2+ cations between NH4+ cation on the exchanger and Pb2+metal cation in solution. Based on these results, NH4-SnP can be proposed as an excellent sorbent for not only removal but also immobilization of Pb2+ ions from water and wastewater. Pb2+ ions were found to be immobilized as insoluble pyromorphite, Pb5(PO4)Cl after high uptakes.KEYWORDS: Pb2+ reactionPb2+ immobilizationpyromorphitePb2+ isothermδ-tin (IV) phosphate Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis research was supported by the College of Agricultural Sciences under Station Research Project No. PEN04705.","PeriodicalId":21680,"journal":{"name":"Separation Science and Technology","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136342383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gold recovery from electronic wastes using a solvent extraction/selective back-extraction strategy","authors":"Zahra Raeisi, Bahman Farajmand, Parvaneh Nakhostin Panahi, Mohammad Reza Yaftian","doi":"10.1080/01496395.2023.2260945","DOIUrl":"https://doi.org/10.1080/01496395.2023.2260945","url":null,"abstract":"ABSTRACTThe present lab-scale investigation describes a simple and efficient approach to the selective solvent extraction and recovery of gold, and copper as a by-product, from Waste Printed Circuit Boards (WPCBs) of different brands of used computers. The process comprised of three steps; leaching of scraps in aqua regia, solvent extraction process under optimized conditions, and ultimately selective back-extraction. The analysis of leach solution by inductively coupled plasma revealed, in addition to gold (0.14 wt%), copper (40.0 wt%), tin (11.9 wt%), and Ni (2.3 wt%) were the other main metals in the WPCBs. A solvent extraction procedure using trioctylamine, as extractant, dissolved in kerosene was employed for the extraction of gold as its anionic chloride-complexes from the leach liquor. The parameters affecting this process including hydrochloric acid concentration, equilibrium time, extractant concentration, initial gold concentration in the sample solution, and the aqueous/organic volume ratio were optimized by means of the statistical technique response surface methodology (RSM). Under the optimized extraction conditions, 99.6% of gold and 23.4% of copper were transferred into the organic phase, while the extracted percentage of other metal ions were negligible. Selective back-extraction by the solution 0.1 M NaOH resulted in the selective precipitation of copper, while the raffinate contained just gold ions.KEYWORDS: Goldcopperrecyclingsolvent extractionselective back-extractiontrioctylamineresponse surface methodology optimization Disclosure statementThe authors declare no conflict of interest.Statement of NoveltyThe present paper aims to report a new, low-cost, efficient, and simple solvent extraction method, using a solution of trioctylamine dissolved in kerosene, followed by a selective back-extraction procedure method, for efficient recovery of gold from leach liquor of Waste Printed Circuit Boards (WPCBs). The presented method allowed also to obtain metallic copper as the by-product","PeriodicalId":21680,"journal":{"name":"Separation Science and Technology","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134886624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oxidation of ferrous ions enhanced by CaMg(CO ₃ ) ₂ for their efficient separation from neodymium solution","authors":"Kaibo Hu, Yucheng Liu, Xiaowen Zhou, Fang Gao, Chuanqi Zhang, Tianci Chen, Ke Li, Jiuyang Lin, Xuewei Li","doi":"10.1080/01496395.2023.2262743","DOIUrl":"https://doi.org/10.1080/01496395.2023.2262743","url":null,"abstract":"ABSTRACTThe waste products of NdFeB magnets are an attractive resource for the recovery of rare earth elements (REEs), especially for neodymium [Nd]. Conventional methods employed to remove ferric (Fe[II]) from Nd solutions involve high energy consumption and the extensive use of chemicals, including oxidants and pH regulators, leading to substantial wastewater generation. In this work, an environmentally friendly approach utilizing CaMg(CO3)2 was presented to remove Fe(II) from Nd solution. Under optimized conditions, including a reaction temperature of 70°C, a CO32-/Fe2+ ratio of 1.5/1, a reaction time of 240 min, and an initial concentration of 200 mg/L, the heterogeneous precipitation reaction on the surface of CaMg(CO3)2 exhibited an exceptional Fe(II) removal efficiency of 98.6%, with a negligible loss of Nd (only 0.8%). It was observed that the CaMg(CO3)2 not only provide a suitable alkaline environment for the selective precipitation of Fe(II), but also significantly enrich the concentration of dissolved oxygen at a high temperature. In fact, at a CaMg(CO3)2 concentration of 2 g/L, the dissolved oxygen concentration in the solution increased significantly to 15.5 mg/L at 70°C. Consequently, the usage of CaMg(CO3)2 facilitated the rapid conversion of Fe(II) to Fe(III) without the need for additional oxidants, which was perfect for the removal of Fe(II) rather than Nd.KEYWORDS: CaMg(CO3)2ferrous ions removalneodymiumdissolved oxygenprecipitation Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis study was financially supported by the Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths (no. E03MYB0302), and the Research Projects of Ganjiang Innovation Academy, Chinese Academy of Sciences (no. E055ZA01), and the Self-deployed Projects of Ganjiang Innovation Academy, Chinese Academy of Sciences, and the Key Research Program of the Chinese Academy of Sciences (no. ZDRW-CN-2021-3), and the China National Key R&D Program (Grant no. 2022YFB3504303).","PeriodicalId":21680,"journal":{"name":"Separation Science and Technology","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135814367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highly efficient and selective 99TcO ₄ ^– uptake from reprocessing low-level liquid waste using a zirconium-based metal−organic framework","authors":"Kankan Patra, Vinit K Mittal, Thichur P Valsala, Arijit Sengupta, Ashok K Sahu, Darshan B Sathe, Raj B Bhatt","doi":"10.1080/01496395.2023.2260949","DOIUrl":"https://doi.org/10.1080/01496395.2023.2260949","url":null,"abstract":"ABSTRACTEfficient and selective sequestration of pertechnetate ions (99TcO4–) from nuclear low-level waste (LLW) solution is very much desirable for the safe treatment of radioactive liquid waste. However, the separation of specific radionuclides from competitors is a huge challenge in separation science. In the nuclear fuel cycle, 99TcO4– is one of troublesome fission products due to long half-life, large inventory in spent fuel, significant radiation hazards, and high environmental mobility of 99TcO4– ions. Recently, the metal−organic framework (MOFs) has shown significant potentials toward 99TcO4– removal. So far, most of the studies were reported using ReO4– ions, an inactive surrogate of 99TcO4– ions, and very few MOF materials are applied for real-time 99TcO4– sequestration from nuclear waste solution in the presence of extreme conditions. Herein, we report 99TcO4– ion removal from low-level liquid nuclear waste solution using zirconium-based metal−organic framework UIO-66-NH2. The material has exhibited fast kinetics and record selectivity toward 99TcO4– ions, making the adsorbent highly promising.HIGHLIGHTS Successful synthesis of zirconium-based metal−organic framework UIO-66-NH2/UIO-66-NH3+ was carried out using the solvothermal method.Characterization of zirconium-based metal−organic framework UIO-66-NH2/UIO-66-NH3+ was carried out using PXRD, SEM, EDX, and elemental analysis.An ion exchange study of 99TcO4– ions was carried out with low-level waste (LLW) solution.UIO-66-NH2/UIO-66-NH3+ has exhibited fast kinetics and record selectivity toward 99TcO4– ions with low-level waste (LLW) solution.Feasibility and selectivity study of the TcO4− extraction process with nuclear reprocessing low-level waste (LLW) solution.KEYWORDS: UiO-66-NH2/NH3+ MOFseparation99TcO4– ionsnuclear waste solution AcknowledgmentsThe authors acknowledge U. Dani, G.M, R &WM, BARC (T), Dr. H.Pal, Professor, Homi Bhabha National Institute & Former Associate Director, Chemistry Group, BARC, Mumbai, and Dr. Biswajit Sadhu, Scientific Officer, HPD, BARC, Mumbai.Disclosure statementNo potential conflict of interest was reported by the author(s).Author informationAll the authors have given permission to the final version of the manuscript.","PeriodicalId":21680,"journal":{"name":"Separation Science and Technology","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135966586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving anti-fouling properties of alumina tubular microfiltration membranes through the use of hydrophilic silica nanoparticles for oil/water separation","authors":"Anirban Ghosh, Ghader Mahmodi, Michael Miranda, Songpei Xie, Madelyn Shaw, Mark Krzmarzick, David J. Lampert, Seok-Jhin Kim, Clint P. Aichele","doi":"10.1080/01496395.2023.2259605","DOIUrl":"https://doi.org/10.1080/01496395.2023.2259605","url":null,"abstract":"ABSTRACTIn this study, hydrophilic silica nanoparticles (Si NPs) were used to modify α-alumina tubular membranes to improve their performance in terms of flux, oil rejection, and anti-fouling properties. Our work focuses on enhancing membrane performance, particularly for difficult applications such as produced water treatment. The prepared membranes were applied for oil-in-water emulsion treatment. After coating hydrophilic Si NPs, the oil contact angle improved from 133.8° to 171.4°. To prevent Si NPs from leaching off the surface of α-alumina tubular membranes, polyvinyl alcohol was used to coat the membranes as a pre-treatment step before Si NP modification. After coating the membrane with Si NPs, the roughness of the membrane surface decreased, likely leading to less fouling. After coating Si NPs, Total Organic Carbon rejection increased from 93.1% for pristine α-alumina tubular membranes to 97.7% for silica-modified membranes because of hydrophilic improvements of the modified membranes. The Si NP coating improved the anti-fouling property of membranes with the flux recovery ratio increasing from 71.3% for pristine α-alumina tubular membranes to 85.9% for silica-modified membranes. Scanning Electron Microscopy, Energy-dispersive X-ray spectroscopy, oil contact angle, and Atomic Force Microscopy characterization tests were done. The tests showed successful Si NPs impregnation and altered wettability.KEYWORDS: Oil/Water emulsionmembrane filtrationdip coatinghydrophilicitysilica modification AcknowledgmentsWe want to thank Dr. Imran Shaik for his assistance in measuring the oil contact angles.Disclosure statementNo potential conflict of interest was reported by the author(s).Statement of noveltyThe membrane development technique combines a novel pre-treatment method (using Polyvinyl alcohol) and a silica grafting technique to produce stable fumed silica coatings on membranes. After incorporating the hydrophilic Si NPs, the oil contact angle (OCA) improved from 133.8° to 171.4°. In addition, the surface roughness and associated containment traps on the membrane surface decreased, likely leading to less fouling. Total Organic Carbon (TOC) rejection increased from 93.1% for pristine α-alumina tubular membranes to 97.7% for silica-modified membranes because of hydrophilic improvements of the modified membranes. The Si NP coating improved the anti-fouling properties of membranes as evidenced by the flux recovery ratio increasing from 71.3% for pristine α-alumina tubular membranes to 85.9% for silica-modified membranes. To the best of our knowledge, there are no literature sources reporting the separation of oil and water using α-alumina membranes modified with fumed silica in a continuous cross-flow process.Additional informationFundingThe work was supported by the National Science Foundation under Grant No. OIA-1946093.","PeriodicalId":21680,"journal":{"name":"Separation Science and Technology","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136099080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two new ammonium-based poly(ionic liquid)s for breaking water-in-crude oil emulsions","authors":"Mahmood M.S. Abdullah, Hamad A. Al-Lohedan","doi":"10.1080/01496395.2023.2266563","DOIUrl":"https://doi.org/10.1080/01496395.2023.2266563","url":null,"abstract":"ABSTRACTTwo new poly(ionic liquid)s (PILs) were synthesized, characterized, and applied in breaking water-in-oil (W/O) emulsions. For that, tetraethylene glycol (TG) was treated with thionyl chloride, obtaining dialkyl chloride (TC). TC was reacted with diamines 1,5-diaminopentane (AP) and 1,11-diaminoundecane (AU), forming the corresponding polyamines, TC-AP and TC-AU. Following this, TC-AP and TC-AU were quaternized with acetic acid (AA), producing poly(ionic liquid)s (PILs), TCAP-PIL, and TCAU-PIL, respectively. Chemical structures, thermal stability, surface activity, aggregation size, and zeta potential measurements were investigated using several techniques. In addition, their performance in breaking (PB) W/O emulsions in different ratios was investigated. TCAP-PIL and TCAU-PIL exhibited high PB at all ratios, while their performance improved as the crude oil ratio decreased. Moreover, TCAU-PIL showed higher PB than TCAP-PIL, which may be linked to the increased hydrophobicity of TCAU-PIL due to increased methylene units in the diamine chain compared to TCAP-PIL.KEYWORDS: Poly(ionic liquid)sdemulsificationwater-in-crude oil emulsion AcknowledgmentsThe authors acknowledge the financial support through Researchers Supporting Project number (RSPD2023R688), King Saud University, Riyadh, Saudi Arabia.Disclosure statementThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.Additional informationFundingThe authors acknowledge the financial support through Research Supporting Project number (RSPD2023R688), King Saud University, Riyadh, Saudi Arabia.","PeriodicalId":21680,"journal":{"name":"Separation Science and Technology","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136100889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Partitioning behavior of dyes in ionic liquids induced aqueous biphasic systems of PPG 725 & ammonium salts","authors":"Emmanuel A. Oke, Sushma P. Ijardar","doi":"10.1080/01496395.2023.2259600","DOIUrl":"https://doi.org/10.1080/01496395.2023.2259600","url":null,"abstract":"ABSTRACTPolypropylene glycol (PPG) is one of the most utilized polymers in aqueous biphasic systems. The low polarity of the polymer-rich phase restricts the application of the ABSs. The applicability of polymer rich ABSs can be induced by adding little amount of ionic liquids as adjuvants. Therefore, an analysis involving the introduction of a small amount of imidazolium-based ILs to PPG 725 + ammonium salts ABSs was performed. The phase diagrams as well as the partitioning behavior of dyes: Orange II (OII), Eriochrome Black T (EBT) and Brilliant Green (BG) were investigated. The addition of 5% 1-butyl-3-methylimidazolium acetate, [BMIM][AC] modulates the partition behaviors of all the investigated dyes. The employed ILs and dyes partitioned preferentially into the polymer-rich phase. The partition coefficients (Kdye) for all the dyes follow the sequence: BG > EBT > OII in all investigated ABSs. The results obtained are in accordance with the logarithm of octanol-water partition coefficients (log Kow) of the respective dyes. The recovery of BG dye from polymer phase has been studied successfully by adsorption onto chitosan.KEYWORDS: Aqueous biphasic systemsphase behaviorammonium saltsionic liquidsdyes AcknowledgmentsEmmanuel A. Oke acknowledges the financial assistance of Africa Scholarship-MEA under the scheme of the Indian Council for Cultural Relations (2019-2020).Disclosure statementNo potential conflict of interest was reported by the author(s).Statement of noveltyThe main objective of this paper is to study the effect of addition of small amount of imidazolium based ILs on aqueous biphasic systems of PPG 725 + inorganic ammonium salts: (NH4)2CO3, NH4H2PO4, (NH4)2SO4 and (NH4)2HPO4. Many researchers conducted similar kind of work on ABS of polymer but the present work is first report on ABS of PPG 725 and ammonium salts. The obtained results shows that require comparatively less amount of ammonium salts. The partitioning of dyes: Orange II (OII), Eriochrome Black T (EBT) and Brilliant Green (BG) were investigated in theses ABSs. The addition of 1-butyl-3-methylimidazolium tetrafluoroborate, [BMIM][BF4]; 1-butyl-3-methylimidazolium acetate, [BMIM][AC]; and 1-butyl-3-methylimidazolium trifluoromethanesulfonate, [BMIM][OTF] were investigated. The present of 5% 1-butyl-3-methylimidazolium acetate, [BMIM][AC] modulates the partitioning behavior of all the investigated dyes. The employed ILs and dyes partitioned preferentially into the polymer-rich phase. [BMIM][AC] is referred as greener ILs hence the studied ABSs can serve as eco-friendly separation systems for removal of dyes.Supplementary materialSupplemental data for this article can be accessed online at https://doi.org/10.1080/01496395.2023.2259600","PeriodicalId":21680,"journal":{"name":"Separation Science and Technology","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136099032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low temperature hydrothermal processing to recover aluminum from nepheline syenite roast-leach residue","authors":"Jayashree Samantray, Amit Anand, Barsha Dash, Malay K. Ghosh","doi":"10.1080/01496395.2023.2260084","DOIUrl":"https://doi.org/10.1080/01496395.2023.2260084","url":null,"abstract":"ABSTRACTNepheline syenite is primarily an alumino-silicate rock which contains a major amount of potassium and aluminum. After potassium recovery through chloridizing roasting followed by water leaching method, the roast leach residue of nepheline syenite was considered for the aluminum extraction process due to its ample aluminum content. Sulfuric acid is chosen over other acids as it prevents the leaching of calcium. A 2^3 full factorial design was employed to study the effects of acid concentration, time, and temperature. Furthermore, to enhance the recovery and to forbid the leaching of silicon, autoclave leaching was preferred.Iron is generally leached with aluminum in the acid leaching process which could be removed effectively by pH adjustment. The leached liquor obtained after purification is evaporated by using a hot water bath. The liquor concentrated on slow evaporation to a point where aluminum sulfate started precipitating. Then, the concentrated liquor was kept overnight at 8°C in a cooling incubator. Aluminum sulfate was produced with 99.80% purity.KEYWORDS: Nepheline syenitealuminumhydrothermal process, aluminum sulfate AcknowledgmentsThe authors also appreciatively recognize the technical assistance provided by the institute staff for the characterization studies. One of the authors (JS) expresses her gratitude to CSIR for providing the fellowship under XII plan period projects.Disclosure statementNo potential conflict of interest was reported by the author(s).Statement of noveltyThe residues obtained after potassium recovery by chloridizing roasting followed by water leaching of silicate minerals and rocks such as feldspar, nepheline syenite etc. are rich in silicon, aluminum, calcium, and iron due to which these can be utilized in various ways. Hence, processing of these residues would be a value addition to the potassium recovery process by increasing the number of products.In our present work, we have tried to recover aluminum from the roast leach residue of nepheline syenite containing 21.43% aluminum as its oxide employing the acid leaching method. Among various acids, leaching with sulfuric acid was better for downstream processing for aluminum recovery. Three parameters chosen for a two[Citation3] full factorial design were time, temperature, and acid concentration. The leaching extent obtained at the design conditions was fed to Minitab 17, and regression equations were generated. Furthermore, to enhance the recovery and to forbid the leaching of silicon, model equations were utilized for autoclave leaching. As the liquor constitutes iron along with aluminum, hence it was removed by pH adjustment to get aluminum-rich liquor which was further processed to get aluminum sulfate crystals.","PeriodicalId":21680,"journal":{"name":"Separation Science and Technology","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136100209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the sorption behavior of tri, tetra and hexavalent f cations on metal–organic framework (MOF), ZIF-67: experimental and theoretical investigation","authors":"J. Mor, Anil Boda, S. K. Sharma, Musharaf Ali, Arijit Sengupta","doi":"10.1080/01496395.2023.2255740","DOIUrl":"https://doi.org/10.1080/01496395.2023.2255740","url":null,"abstract":"ABSTRACTMetal–organic frameworks (MOFs) are a class of compounds with modern-age technological importance due to diverse structural topologies, porosity, and modularity. ZIF-67 has been synthesized for efficient extraction of f cations in different oxidation states (UO22+, Th4+ and Eu3+) from aqueous pH medium exhibiting the trend in sorption efficiency as: KdTh(6.19 × 103) > KdU (5.20 × 103) > KdEu (1.58 × 103) in accordance to their chemical potential. Langmuir isotherm was found to be predominate with sorption capacity 85.9 mg g−1, 137.4 mg g−1 and 50.6 mg g−1 for U, Th and Eu, respectively. The sorption predominantly proceeded via pseudo 2nd order rate kinetics with rate constants: k2U ~0.089 g mg−1 min−1, k2Th ~0.011 g mg−1 min−1 and k2Eu ~0.04 g mg−1 min−1. The processes were found to be spontaneous as revealed from negative ΔG values; and endothermic in nature (ΔHU ~10.5 kJ mol−1; ΔHTh ~12.8 kJ mol−1; ΔHEu ~8.3 kJ mol−1). The sorption proceeded via the formation of an inner sphere complex as indicated from their enhancement in the entropy values on sorption due to the release of water molecules. The Density Functional Theory (DFT) predicted selectivity using binding energy (ZIF-67-Eu3+ ~ -60.90 eV, ZIF-67-Th4+ ~ -70.78 eV, ZIF-67-Th4+ ~ -69.52 eV) is in line with the experimental selectivity of Th4+ > UO22+ > Eu3+. Total density of states (TODS) and Projected density of States (PODS) were estimated in order to understand the interaction between the ZIF-67 and f cations.KEYWORDS: ZIF-67f-cationssorptionisothermradiolytic stability AcknowledgmentsThe authors wish to acknowledge Dr. P. K. Mohapatra, Associate Director, RC & I Group, BARC & Head, Radiochemistry Division.Disclosure statementNo potential conflict of interest was reported by the author(s).Metal-Organic Framework noveltyMetal-Organic Framework (MOF), ZIF-67 has been synthesized for efficient extraction of f-cations in different oxidation states (UO22+, Th4+ and Eu3+) from aqueous pH medium exhibiting the trend in sorption efficiency as: KdTh (6.19 × 103) > KdU (5.20 × 103) > KdEu (1.58 × 103) in accordance to their chemical potential. Langmuir isotherm was found to be predominate with sorption capacity 85.9 mg g−1, 137.4 mg g−1 and 50.6 mg g−1 for U, Th and Eu, respectively. The sorption predominantly proceeded via pseudo 2nd order rate kinetics with rate constants: k2U ~0.089 g mg−1 min−1, k2Th ~0.011 g mg−1 min−1 and k2Eu ~0.04 g mg−1 min−1. The processes were found to be spontaneous as revealed from negative ΔG values, and endothermic in nature (ΔHU ~10.5 kJ mol−1; ΔHTh ~12.8 kJ mol−1 ΔHEu ~8.3 kJ mol−1). The sorption proceeded via the formation of an inner sphere complex as indicated from their enhancement in the entropy values on sorption due to the release of water molecules. The Density Functional Theory (DFT) predicted selectivity using B.E. (ZIF-67-Eu3+ ~ −60.90 eV, ZIF-67-Th4+ ~ −70.78 eV, ZIF-67-Th4+ ~ −69.52 eV) is in line with the experimental selectivity of Th4+ > UO","PeriodicalId":21680,"journal":{"name":"Separation Science and Technology","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136235236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}