Synthesis of Sodalite from Sepiolite by Alkali Fusion Method and Its Application to Remove Fe3+, Cr3+, and Cd2+ from Aqueous Solutions

This is an accepted manuscript of an article published by Mary Ann Liebert in Environmental Engineering Science on 16/06/2020, available online: https://doi.org/10.1089/ees.2019.0492 The accepted version of the publication may differ from the final published version.The aim of this article is to study the sodalite synthesis from sepiolite through an alkali fusion method followed by hydrothermal process, and to investigate its application in heavy metal removal. The fused precursors were prepared through mixing sepiolite with sodium hydroxide (NaOH) and potassium hydroxide (KOH) activators, at 650°C. Hydrothermal reactions were performed at 100°C, 140°C, 180°C, and 220°C. Under the hydrothermal treatment at 140°C, pure sodalite 1 was formed from fused precursor of sepiolite-NaOH, for 48 h, while pure sodalite 2 was synthesized from fused mixture of sepiolite and KOH, at 180°C for 72 h. Pure sodalites and raw material were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) analyses. The potential of two sodalites for removal of Fe3+, Cr3+, and Cd2+ cations from 0.001, 0.01, and 0.1 M aqueous solutions was evaluated through a series of batch experiments. The optimum adsorption of Fe3+ and Cr3+ was achieved from 0.001 to 0.01 M solutions. In contrast, Cd2+ was removed most efficiently from 0.1 M solution. In terms of contact time, the maximum adsorption amount from 0.001 M solutions was achieved between 1 and 2 h for pure sodalite 1 and between 30 min and 1 h for pure sodalite 2. The highest adsorption rate from 0.01 to 0.1 M solutions was observed between 30 min and 1 h, for both pure sodalite 1 and pure sodalite 2. Sepiolite was shown to be successfully used as raw material for formation of pure sodalite, and subsequently, pure sodalite has considerable capability to be used for environmental cleanups.Published onlin

Impacts of ultramafic outcrops in Peninsular Malaysia and Sabah on soil and water quality

This study focused on the influence of ultramafic terrains on soil and surface water environmental chemistry in Peninsular\ua0Malaysia and\ua0in\ua0the State of Sabah also in\ua0Malaysia. The sampling included 27 soils from four isolated outcrops at\ua0Cheroh, Bentong, Bukit Rokan, and Petasih from Peninsular Malaysia and sites near Ranau in\ua0Sabah. Water samples were also collected from rivers and subsurface waters interacting with the ultramafic bodies in these study sites. Physico-chemical parameters (including pH, EC, CEC) as well as the concentration of major and trace elements were measured in these soils and waters. Geochemical indices (geoaccumulation index, enrichment factor, and concentration factor) were calculated. AlO and FeO had\ua0relatively high concentrations in the samples. A depletion in MgO, CaO, and NaO was observed as a result of leaching in tropical climate, and in relation to weathering and pedogenesis processes. Chromium, Ni, and Co were enriched and confirmed by the significant values obtained for Igeo, EF, and CF, which correspond to the extreme levels of contamination for Cr and high to moderate levels of contamination for Ni and Co. The concentrations of Cr, Ni, and Co in surface waters did not reflect the local geochemistry and were within the permissible ranges according to WHO and INWQS standards. Subsurface waters were strongly enriched by these elements and exceeded these standards. The association between Cr and Ni was confirmed by factor analysis. The unexpected enrichment of Cu in an isolated component can be explained by localized mineralization in Sabah

Origin and Evolution of Oscillatory Zoned Garnet from Kasva Skarn, Northeast Tafresh, Iran

Within the central Urumieh-Dokhtar Magmatic Belt of northern Iran, the Kasva skarn deposit (KSD) formed by metasomatic alteration of Eocene intercalated carbonate and volcaniclastic sediments in response to Oligo-Miocene intrusion by granitoid porphyries. The KSD contains abundant oscillatory-zoned garnet crystals, which are characterized by isotropic cores of nearly pure andradite that are rimmed by anisotropic grossular–andradite (grandite). The Fe-rich andraditic cores are enriched in U and LREE, with positive Eu anomalies, whereas the Al-rich granditic rims are enriched in Ti, Nb, Zr, Hf, and HREE, without Eu anomalies. Variation in optical and chemical features in Fe- and Al-rich garnet are controlled by external factors such as (1) infiltration of compositionally distinct fluids, (2) incorporation of LREE and U at the {X} site in association with substitution of Fe^(3+) for Al^(3+) at [Y] within the crystal structure of andraditic garnet, and (3) substitution of Ti and HFSE for Al in granditic garnet

Characterization of Iranian bentonites to be used as pharmaceutical materials

Ten Iranian bentonites, sampled fromthe deposits of Chah-Golestan, Chah-Pirouz, Chah-Keshmir and Chah-Taleb (Sarayan), Gholeh-Gelia and Kharman-Sar (Ferdows, Khorasan), Mehrejan (Khoor) and Manian (Zagros) were analyzed to evaluate their potentialities as pharmaceutical products. The mineralogy, chemistry, pH, microbial content, powder flowcharacteristics, swelling capacity, cation exchange capacity, specific surface area, sedimentation volume, and rheological properties of all samples were determined. The bentonite located in carbonate rocks (Zagros) is made up of calcium montmorillonite (97%) and quartz (3%). The rest of the bentonites are hosted by Eocene volcanic rocks and aremainlymade up of sodiummontmorillonite (47%–84%) and cristobalite (up to 39%), with lesser quantities of quartz, calcite, plagioclase, zeolites and halite. Two of the samples (those located at Manian and Chah-Golestan C) showed appropriate composition, purity and technical properties to be used in pharmaceutical applications, whereas the rest would require purification or improvement of their properties. In particular, the samples could be used for topical dosage forms as rheological additives

Petrogenesis of Miocene igneous rocks in the Tafresh area (central Urumieh‐Dokhtar magmatic arc, Iran): Insights into mantle sources and geodynamic processes

Cenozoic tectono-magmatism in Iran is widely considered to be related to subduction of the Neo-Tethys Ocean. We employed whole-rock and mineral geochemistry and isotopic data of intrusive rocks from Tafresh, central Urumieh-Dokhtar magmatic arc, to evaluate the role of the mantle in magmatism, to assess the timing of emplacement, and to interpret the tectonic setting. Rock compositions range from gabbro or gabbro-diorite (plagioclase + pyroxene ± olivine), to diorite (plagioclase + amphibole ± pyroxene), to granodiorite (quartz + plagioclase + K-feldspar + amphibole + biotite), exhibiting high-alumina calc-alkaline affinity. Major oxide and trace element variations vary systematically from less to more evolved rocks suggesting a major role for fractional crystallization processes. Zircon LA-ICP-MS U–Pb ages of major rock types are in the range of 24–19 Ma, whereas those of gabbroic dikes are ~17.5 Ma. ԐNd values range between -1.8 and 3.7, and (87Sr/86Sr)i is narrowly restricted to 0.705–0.706, suggesting a common mantle source. The enrichment in light rare earth element (REE) enrichment and flat heavy REE patterns couple depletion of Nb–Ta–Ti indicate that subducting oceanic crust had interacted with the overlying mantle wedge. High-alumina, mid-Mg# Tafresh plutonic rocks formed from hydrous melts from which Ca-pyroxene and magnetite crystallized earlier than plagioclase, whereas late-crystallizing zircon nucleated while magma traversed through lithospheric mantle and Cadomian crust. Modelling of isotope and incompatible-element patterns suggests the contribution of no more than ~5% molten sediment or other crustal components in Tafresh magma, at a developmental stage before most plagioclase and amphibole had crystallized. The Miocene Tafresh plutons originated during the final stages of subduction, before the collision between the Arabian and Eurasian plates

The world-class Koushk Zn-Pb deposit, Central Iran: a genetic model for vent-proximal shale-hosted massive sulfide (SHMS) deposits - Based on paragenesis and stable isotope geochemistry

© 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The Koushk Zn-Pb deposit is the largest known and least deformed and non-metamorphosed Early Cambrian shale-hosted massive sulfide (SHMS) deposit at Central Iran. The current remaining reserves are estimated to be greater than 14 Mt ore, averaging 7% Zn and 1.5% Pb; the primary resources ore of the deposit is estimated to be more than 60 Mt. At this deposit, different hydrothermal ore styles (bedded ore, vent complex, and feeder zone) are well preserved within the Lower Cambrian black siltstones and shales. According to fluid-rock interaction and different ore-forming processes in SHMS systems, these ore facies with extensive hydrothermal alteration provide unique conditions to understand critical textural and geochemical frameworks to present a genetic model. In this research, we focus on different paragenetic stages of sulfide mineralization and fluid-rock interactions in different ore styles from the Koushk SHMS deposit. The paragenetic relationship provides the context for the interpretation of stable isotopes (S, C, and O) in hydrothermal sulfides and carbonates. Detailed petrography and paragenetic studies represent three major generations of sulfide mineralizations at different ore zones: (1) stage I includes very fine-grained (<6 µm) framboids, spherulite pyrite (py1), associated with minor fine-grained disseminated sphalerite (sp1), and galena (gn1); (2) Stage II is composed of a diagenetic intergrowth of coarse-grained framboids and spherulite pyrite, packed polyspherulite aggregates and pyrite nodules (py2) replacing diagenetic barite and carbonate nodules, and are followed with coarse-grained sphalerite (sp2) and galena (gn2) that replace former sulfides and barite, deposited as disseminated, laminated and sulfide-rich banded textures; (3) stage III of sulfide mineralization is characterized by vent complex development (VCD) over the feeder zone, hydrothermal brecciation, dissolution of rock-forming minerals, and extensive replacement of earlier sulfides and barite, leading to deposition of stage III of ore sulfides. The oxygen and carbon isotopes values, for fluid in equilibrium with hydrothermal calcite and dolomite in this deposit range from d18O +8 to +16.7‰ and d13C from -8.3 to -4.3‰, are generally compatible with basinal brines and formation water as fluid sources. In addition, highly positive d34S values of hydrothermal sulfides (+6.5 to +36.7‰) in different ore stages of the Koushk deposit are consonant with other SHMS deposits. Textural relationships and S isotope data reveal that the contribution of bacterial sulfate reduction (BSR) in the Zn-Pb mineralization is not so significant, but the thermochemical sulfate reduction (TSR) nd direct barite replacement could provide sufficient sulfur for the main sulfide mineralization in the SHMS deposits. Also, the data presented in this paper are against a syngenetic, purely synsedimentary-exhalative model, and give prominence to that vent-proximal SHMS deposits formed predominantly during the diagenesis in the uppermost sediment pile and replacement of host rocks during vent complex development (VCD) processes.To memorialize one of the first author’s best teachers, Donald F. Sangster, for the love and support, and for the guidance and patience in dealing with the many problems arose during this and other projects about the sediment-hosted Zn-Pb deposits of Iran, from 2007 to 2018. The Serveis Científico-Tècnics de la Universitat de Barcelona and the research grant 2009SGR-00444 of the Departament d’Universitats, Recerca i Societat de la Informació (Generalitat de Catalunya) supported sulfur isotope analyses. The Instituto de Geofísica and Instituto de Geología of the Universidad Nacional Autónoma de México (UNAM) supported electron microprobe analyses, which were done with the assistance of Carlos Linares, and carbon and oxygen isotopes analyses. The authors thank Bafq Mining Company (BMC) for allowing access to the deposit and providing invaluable support on-site through access underground exposures. We sincerely thank Jan Peter for his helpful comments and advice, and discussions on the geology of Central Iran. The manuscript has benefited from helpful comments by David Lentz and an anonymous reviewer, and careful editorial handling by Maria Boni and Huayong Chen.Peer ReviewedPostprint (author's final draft