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  • 1.
    Trublet, Mylene
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Scukins, Edvards
    Aeronautics, Department of Flight Data and Navigation, SAAB, Linköping, Sweden.
    Carabante, Ivan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Rusanova-Naydenova, Daniela
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Competitive Sorption of Metal Ions on Titanium Phosphate Sorbent(TiP1) in Fixed-Bed Columns: A Closed-Mine Waters Study2019Ingår i: ACS Sustainable Chemistry & Engineering, ISSN 2168-0485, Vol. 7, nr 9, s. 8145-8154Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Sorptionfixed-bed column experiments were performed using atitanium phosphate ion-exchanger composed of−H2PO4units [TiO(OH)(H2PO4)·H2O]. Model mine water containingfive divalent metal ions (Cu2+,Zn2+,Mn2+,Ni2+,and Co2+) and a few closed-mine water samples were treated to evaluate the sorptionpreference of the material. For thefirst time, dynamic ion-exchange capacities(estimated to be between 3.2 and 4.2 mequiv g−1) and static ion-exchange uptakes(calculated to be between 3.1 and 3.5 mequiv g−1) were obtained for the same TiP1sorbent and data were discussed in terms of sorption behavior. It was found thatsorption processes on TiP1 in model and closed-mine waters during a columnexperiment could be accurately predicted from the corresponding batch experiment(including the sorbent’s capacities in different types of waters). A competitivesorption phenomenon in favor of Cu2+on TiP1 was established for all cases, pointingtoward the possibility of isolating pure copper concentrate from closed-mine waters.The relatively high amounts of calcium and magnesium ions present in mine waters did not appear to considerably affect theselectivity of TiP1 material. Exploratory experiments for sorbent regeneration and desorption using a low concentration of nitricacid were demonstrated.

  • 2.
    Kasiuliene, Alfreda
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Carabante, Ivan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Bhattacharya, Prosun
    Department of Sustainable Development, Environmental Science and Engineering, Royal Institute of Technology, Stockholm.
    Kumpiene, Jurate
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Hydrothermal carbonisation of peat-based spent sorbents loaded with metal(loid)s2019Ingår i: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 26, nr 23, s. 23730-23738Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hydrothermal carbonisation (HTC) is a wet and relatively low-temperature process where, under autogenous pressures, biomass undergoes a chain of reactions leading to the defragmentation of organic matter. As well as its other uses (e.g. for producing low-cost carbon-based nano-compounds), HTC is utilised for the treatment of wet wastes, such as manure and biosludge. This study aimed to determine if hydrothermal carbonisation is a feasible treatment method for spent sorbents that are highly enriched with arsenic, chromium, copper, and zinc. The chemical properties of hydrochar and process liquid were evaluated after HTC treatment, where peat-based spent sorbents were carbonised at 230 °C for 3 h. Analysis of Fourier transform-infrared spectra revealed that during HTC, the oxygenated bonds of ethers, esters, and carboxylic groups were cleaved, and low-molecular-weight organic fragments were dissolved in the process liquid. A large fraction of arsenic (up to 62%), copper (up to 25%), and zinc (up to 36%) were transferred from the solids into the process water. Leaching of these elements from the hydrochars increased significantly in comparison with the spent sorbents.

  • 3.
    Kumpiene, Jurate
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Antelo, Juan
    Technological Research Institute, University of Santiago de Compostela, Spain.
    Brännvall, Evelina
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Carabante, Ivan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Ek, Kristina
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Samhällsvetenskap.
    Komárek, Michael
    Department of Environmental Geosciences, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Czech Republic.
    Söderberg, Charlotta
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Samhällsvetenskap.
    Wårell, Linda
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Samhällsvetenskap.
    In situ chemical stabilization of trace element-contaminated soil: Field demonstrations and barriers to transition from laboratory to the field : A review2019Ingår i: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 100, s. 335-351Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The chemical stabilization, or immobilization, of trace elements (metals and metalloids; TE) in contaminated soil has been studied for decades. A vast number of scientific publications are available on the method performance in laboratory settings, reporting that the application of various soil amendments to contaminated soil reduces TE mobility, bioavailability and toxicity. The most commonly used soil amendments include organic matter, iron oxides, phosphates, ashes, and lately biochar, alone or in combination with each other and/or lime. Most of the implemented field studies show a certain degree of improvement in soil and/or vegetation status following amendment. Regardless the positive performance of the technique in the laboratory, field validations and demonstrations remain scarce. The establishment of a field experiment often involves permits from authorities and agreements with site owners, both of which are considerably more time-consuming than laboratory tests. Due to conservative institutional structures, public authorities have been slow to adopt alternative remediation technologies, especially when the total TE concentration in soil remains the same and all of the associated risks are not yet convincingly described. For this reason, researchers should also focus on enhancing public knowledge of alternative remediation techniques so that future projects which aim to demonstrate the effectiveness of in situ immobilization techniques under natural conditions will be supported.

  • 4.
    Kasiuliene, Alfreda
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Carabante, Ivan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Bhattacharya, Prosun
    Department of Sustainable Development, Environmental Science and Engineering, Royal Institute of Technology, Stockholm.
    Kumpiene, Jurate
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Treatment of metal (loid) contaminated solutions using iron-peat as sorbent: is landfilling a suitable management option for the spent sorbent?2019Ingår i: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study firstly aimed to investigate the potential of simultaneous metal (loid) removal from metal (oid) solution through adsorption on iron-peat, where the sorbent was made from peat and Fe by-products. Up-flow columns filled with the prepared sorbent were used to treat water contaminated with As, Cu, Cr, and Zn. Peat effectively adsorbed Cr, Cu, and Zn, whereas approximately 50% of inlet As was detected in the eluent. Iron-sand was effective only for adsorbing As, but Cr, Cu, and Zn were poorly adsorbed. Only iron-peat showed the simultaneous removal of all tested metal (loid)s. Metal (loid) leaching from the spent sorbent at reducing conditions as means to assess the behaviour of the spent sorbent if landfilled was also evaluated. For this purpose, a standardised batch leaching test and leaching experiment at reducing conditions were conducted using the spent sorbent. It was found that oxidising conditions, which prevailed during the standardised batch leaching test, could have led to an underestimation of redox-sensitive As leaching. Substantially higher amounts of As were leached out from the spent sorbents at reducing atmosphere compared with oxidising one. Furthermore, reducing environment caused As(V) to be reduced into the more-toxic As (III).

  • 5.
    Kasiuliene, Alfroda
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Carabante, Ivan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Bhattacharya, Prosun
    Department of Sustainable Development, Environmental Science and Engineering, Royal Institute of Technology.
    Carporale, A.G.
    Department of Agricultural Sciences, University of Naples Federico II.
    Adamo, P.
    Department of Agricultural Sciences, University of Naples Federico II.
    Kumpiene, Jurate
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Removal of metal(oid)s from contaminated water using iron-coated peat sorbent2018Ingår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 198, s. 290-296Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study aimed at combining iron and peat to produce a sorbent suitable for a simultaneous removal of cations and anions from a solution. Peat powder, an industrial residue, was coated with iron by immersing peat into iron salt solutions. The adsorption efficiency of the newly produced sorbent towards As, Cr, Cu and Zn was tested by means of batch adsorption experiments at a constant pH value of 5. Coating of Fe on peat significantly increased the adsorption of As (from <5% to 80%) and Cr (from <3% to 25%) in comparison to uncoated peat. Removal of cations on coated peat slightly decreased (by 10–15%), yet remained within acceptable range. Electron Microscopy combined with X-Ray Energy Dispersive Spectroscopy revealed that iron coating on the peat was rather homogenous and As and Cr were abundantly adsorbed on the surface. By contrast, Cu and Zn displayed a sparing distribution on the surface of the iron coated peat. These results indicate that iron-peat simultaneously target sufficient amounts of both cations and anions and can be used for a one-step treatment of contaminated groundwater

  • 6.
    Lidelöw, Sofia
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Macsik, Josef
    Ecoloop Stockholm.
    Carabante, Ivan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Kumpiene, Jurate
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Leaching behaviour of copper slag, construction and demolition waste and crushed rock used in a full-scale road construction2017Ingår i: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 204, nr 1, s. 695-703Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The leaching behaviour of a road construction with fayalitic copper slag, recycled concrete and crushed rock as sub-base materials was monitored over ten years. All studied materials used in the road construction, including crushed rock, contained concentrations of several elements exceeding the guideline values recommended by the Swedish EPA for total element concentrations for waste materials used in constructions. Despite that, leaching from the road construction under field conditions in general was relatively low. The leachates from the recycled materials contained higher concentrations of several constituents than the leachates from the reference section with crushed rock. The leaching of the elements of interest (Cr, Mo, Ni, Zn) reached peak concentrations during the second and fourth (Cu) years and decreased over the observation period to levels below the Swedish recommended values. Carbonation of the concrete aggregates caused a substantial but short-term increase in the leaching of oxyanions such as chromate. The environmental risks related to element leaching are highest at the beginning of the road life. Ageing of materials or pre-treatment through leaching is needed prior to their use in construction to avoid peak concentrations. Also, the design of road constructions should be adjusted so that recycled materials are covered with low-permeability covers, which would minimize the exposure to atmospheric precipitation and weathering.

  • 7.
    Kumpiene, Jurate
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Nordmark, Désirée
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Carabante, Ivan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Sužiedelytė-Visockienė, Jūratė
    Department of Geodesy and Cadastre, Vilnius Gediminas Technical University.
    Česlovas Aksamitauskas, Vladislovas
    Department of Geodesy and Cadastre, Vilnius Gediminas Technical University.
    Remediation of soil contaminated with organic and inorganic wood impregnation chemicals by soil washing2017Ingår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 184, s. 13-19Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to evaluate the efficiency of a large scale washing/wet sieving technique for a soil contaminated with wood impregnation chemicals by 1) defining the final distribution of trace elements (As, Cu, Cr, Zn) and polycyclic aromatic hydrocarbons (PAH) in separated soil particle size fractions; and 2) defining the leaching behavior of the contaminants in these soil fractions. A soil washing experiment was implemented at waste management facility in Sweden using a full scale soil sorting and washing equipment. Five tons of soil was loaded to the equipment and wet-sieved into the following fractions: >16 mm, 8–16 mm, 2–8 mm, 0.2–2 mm, <0.2 mm and a fraction that floated on top of the slurry before the final separation phase, composed of organic matter (OM). Analysis of total concentrations of contaminants in all soil fractions indicated that wet sieving/soil washing was not efficient to reduce the total volume of soil that needs further treatment. Even the coarsest soil fractions (>8 mm) contained elevated concentrations of total As and PAH. Leaching of As from all washed soil fractions was so high, that none of the particle size fractions could be disposed of without additional treatment.

  • 8.
    Kumpiene, Jurate
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Nordmark, Desiree
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Hamberg, Roger
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Carabante, Ivan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Simanavičienė, Rūta
    Department of Mathematical Modelling, Vilnius Gediminas Technical University.
    Česlovas Aksamitauskas, Vladislovas
    Department of Geodesy and Cadastre, Vilnius Gediminas Technical University.
    Leaching of arsenic, copper and chromium from thermally treated soil2016Ingår i: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 183, nr 3, s. 460-466Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Thermal treatment, if properly performed, is an effective way of destroying organic compounds in contaminated soil, while impact on co-present inorganic contaminants varies depending on the element. Leaching of trace elements in thermally treated soil can be altered by co-combusting different types of materials. This study aimed at assessing changes in mobility of As, Cr and Cu in thermally treated soil as affected by addition of industrial by-products prior to soil combustion. Contaminated soil was mixed with either waste of gypsum boards, a steel processing residue (Fe3O4), fly ash from wood and coal combustion or a steel abrasive (96.5% Fe0). The mixes and unamended soil were thermally treated at 800 °C and divided into a fine fraction <0.125 mm and a coarse fraction >0.125 mm to simulate particle separation occurring in thermal treatment plants. The impact of the treatment on element behaviour was assessed by a batch leaching test, X-ray absorption spectroscopy and dispersive X-ray spectrometry. The results suggest that thermal treatment is highly unfavourable for As contaminated soils as it increased both the As leaching in the fine particle size fraction and the mass of the fines (up to 92%). Soil amendment with Fe-containing compounds prior to the thermal treatment reduced As leaching to the levels acceptable for hazardous waste landfills, but only in the coarse fraction, which does not justify the usefulness of such treatment. Among the amendments used, gypsum most effectively reduced leaching of Cr and Cu in thermally treated soil and could be recommended for soils that do not contain As. Fly ash was the least effective amendment as it increased leaching of both Cr and As in majority of samples.

  • 9.
    Garcia, Gustavo
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Aguilar, Wilson
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Carabante, Ivan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Cabrera, Saúl
    Chemistry Research Institute IIQ, San Andres Mayor University UMSA, La Paz.
    Hedlund, Jonas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Mouzon, Johanne
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Preparation of zeolite A with excellent optical properties from clay2015Ingår i: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 619, s. 771-777Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Discoloration of zeolite A powder is a common problem when natural raw materials such as kaolin clay are used because of the formation of colored iron compounds. In this study, we report on a novel method to produce zeolite A with excellent optical properties, from clays. The brightness is as high as 94.5 and the yellowness is as low as 3.0. The product is comprised of intergrown zeolite A crystals with cubic habit and a length ranging between 0.5 and 2 μm. Good optical properties are obtained when the raw material contains magnesium, as some natural raw materials do, or alternatively, when a magnesium compound is added to the raw material. Magnesium probably forces iron inside colorless extraneous magnesium aluminosilicate compounds. This simple process appears very promising for the preparation of zeolite A with good optical properties from inexpensive natural raw materials.

  • 10.
    Carabante, Ivan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Mouzon, Johanne
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Kumpiene, Jurate
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Grahn, Mattias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Fredriksson, Andreas
    Mining Technology R and D, LKAB Kiruna Mine.
    Hedlund, Jonas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Reutilization of porous sintered hematite bodies as effective adsorbents for arsenic(V) removal from water2014Ingår i: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 53, nr 32, s. 12689-12696Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A method was developed to enhance the arsenic adsorption capacity of porous bodies of sintered hematite. The method comprised the formation of a coating of 1 wt % iron oxide nanoparticles on the raw material. The nanoparticles showed two distinct habits: spherical habit, likely ferrihydrite, and acicular habit, likely goethite and/or akaganéite. The specific surface area of the hematite raw material increased from 0.5 to 3.75 m2/g, and the adsorption capacity increased from negligible to 0.65 mg of [As]/g as calculated from equilibrium and breakthrough adsorption data. Equilibrium adsorption data of arsenate on the adsorbent from a solution at pH 5 followed the Langmuir model, while breakthrough adsorption data for a 500 μg/L arsenate solution at pH 5 followed the Thomas model. The adsorbed arsenic could be desorbed using distilled water at pH 12. These results show the potential for the reutilization of waste products comprising coarse hematite bodies as adsorbents.

  • 11.
    Carabante, Ivan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Arsenic (V) adsorption on iron oxide: implications for soil remedeation and water purification2012Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Addition of iron oxide based adsorbents to arsenic contaminated soils has been proposed as a mean to reduce the mobility of arsenic in the soil. However, the conditions in the soil such as pH value, the presence of phosphate after addition of fertilizer to the soil or the presence of Zn (II) as a co-contaminant may affect the adsorption of arsenate on the iron oxide and may therefore have implications for the mobility of arsenic in the remediated soil.In the present work, a new flow method was developed to study the adsorption of arsenate on synthetic iron oxide with high surface area (ferrihydrite) in situ by means of Attenuated Total Reflection – Fourier Transform Infrared (ATR – FTIR) spectroscopy and the method was used for studying how the adsorption of arsenate was affected by the pH/pD value, the presence of phosphate and Zn (II) in the system. The highest adsorption of arsenate was found at pD 4 and decreased as the pD value increased. The arsenate complexes formed on ferrihydrite appeared to be very stable at pD 4, while the stability decreased as the pD value increased. Arsenate showed a higher adsorption affinity than phosphate on ferrihydrite under the conditions studied. However, phosphate was able to replace about 10 % of pre-adsorbed arsenate on ferrihydrite at pD 4 and about 20 % of the pre-adsorbed arsenate at pD 8.5 in equimolar concentrations of phosphate and arsenate. Phosphate replaced 30 % of pre-adsorbed arsenate at pD 4 and up to 50 % of pre-adsorbed arsenate at pD 8.5 when the concentration of phosphate in the system was 5 times higher than that of arsenate. Batch adsorption experiments indicated an enhancement in the arsenate removal from a ferrihydrite suspension in the presence of Zn (II) at pH 8 in accordance with previous reports. However, no adsorption of arsenate on ferrihydrite in the presence of high concentrations of Zn (II) in the system was observed by infrared spectroscopy. Instead, precipitation of zinc hydroxide carbonate followed by arsenate adsorption on the zinc precipitate was found to be the most likely explanation of these results.Although iron oxides are selective towards arsenate, high specific surface areas are required to achieve sufficiently high adsorption capacity. A method of increasing the specific surface area of coarse hematite particles to obtain a good adsorbent was also developed in the present work. The method comprises an acid treatment to produce iron ions followed by hydrolysis to precipitate an iron oxy-hydroxide coating on the hematite particles. While the arsenate adsorption capacity of the original coarse hematite particles was found to be negligible, the sintered coarse hematite particles showed good potential as an adsorbent for arsenate with an adsorption capacity of about 0.65 mg[As]/g.The method developed for studying adsorption on iron oxides by in situ ATR - FTIR spectroscopy was further developed for studying the adsorption of flotation collectors on iron oxides. Iron ore is often separated from gangue minerals by means of reverse flotation in which a surfactant should selectively adsorb on the gangue mineral rendering it hydrophobic. However, unwanted adsorption of the surfactants on the iron oxide has been reported to affect the production of iron ore pellets. A method was developed to study the adsorption of the surfactant Atrac 1563 on synthetic hematite in situ by means of ATR - FTIR spectroscopy. The adsorption of Atrac 1563 on hematite at pH 8.5 was found to mostly occur via interactions between the polar ester and ethoxy groups of the surfactant and the hematite surface.

  • 12.
    Carabante, Ivan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Grahn, Mattias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Holmgren, Allan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Kumpiene, Jurate
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Hedlund, Jonas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Influence of Zn(II) on the adsorption of arsenate onto ferrihydrite2012Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, nr 24, s. 13152-13159Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Addition of iron oxide to arsenic-contaminated soil has been proposed as a means of reducing the mobility of arsenic in the soil. Arsenic and zinc are common coexisting contaminants in soils. The presence of zinc therefore may affect the adsorption properties of arsenic on iron oxide, and may thus affect its mobility in the soil. The influence of Zn(II) on the adsorption of arsenate ions on iron oxide was studied. Batch adsorption experiments indicated that Zn(II) increased the arsenate removal from a solution by ferrihydrite at pH 8. However, ATR-FTIR spectroscopy showed that no adsorption of arsenate on a ferrihydrite film occurred at pD 8 in the presence of Zn(II). Precipitation of zinc hydroxide carbonate followed by arsenate adorption onto the precipitate was found to be a plausible mechanism explaining the arsenate removal from a solution in the presence of Zn(II) at pH/pD 8. The previously suggested mechanisms attributing the enhanced removal of arsenate from solution in the presence of Zn(II) to additional adsorption on iron oxides could not be verified under the experimental conditions studied. It was also shown that at pH/pD 4, the presence of Zn(II) in the system did not significantly affect the adsorption of arsenate on ferrihydrite.

  • 13. Carabante, Ivan
    et al.
    Grahn, Mattias
    Hedlund, Jonas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    In situ ATR-FTIR studies on the competitive adsorption of arsenate and phosphate on ferrihydrite2010Ingår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 351, nr 2, s. 523-531Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the present study, in-situ ATR-FTIR spectroscopy was used for the first time to study the competitive adsorption of phosphate and arsenate on ferrihydrite. Deuterium oxide was used as solvent to facilitate the interpretations of recorded infrared spectra.It was found that arsenate and phosphate adsorbed more strongly at lower pD values, showing similarities in the adsorption behavior as a function of pD. However, arsenate complexes were found to be more strongly adsorbed than phosphate complexes in the pD range studied. About five times higher concentration of phosphate in solution was needed to reduce the absorbance due to pre-adsorbed arsenate to the same relative level as for pre-adsorbed phosphate, which was desorbed using a solution containing equal (molar) concentrations in arsenate and phosphate. At pD 4, two phosphate complexes were adsorbed on the iron oxide, one deuterated and one de-deuterated. When phosphate was pre-adsorbed and arsenate subsequently added to the system, the deuterated phosphate complex desorbed rapidly while the de-deuterated phosphate complex was quite stable. At pD 8.5, only the de-deuterated phosphate complex was adsorbed on the iron oxide. Moreover, the arsenate adsorbed was also predominantly de-deuterated as opposite to the arsenate adsorbed at pD 4. During the substitution experiments the configuration of these complexes on the iron oxide surface did not change. To the best of our knowledge, this is the first time this difference in stability of the different phosphate complexes is reported and shows the power of employing in-situ spectroscopy for this kind of studies.

  • 14.
    Potapova, Elisaveta
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Carabante, Ivan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Grahn, Mattias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Holmgren, Allan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Hedlund, Jonas
    Studies of collector adsorption on iron oxides by in-situ ATR-FTIR spectroscopy2010Ingår i: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 49, nr 4, s. 1493-1502Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, the adsorption of three model collectors, viz., poly(ethylene glycol) monooleate (PEGMO), ethyl oleate, and maleic acid, as well as the commercial fatty-acid-type collector Atrac 1563, was studied in situ on synthetic hematite using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The adsorption behavior of the studied compounds on hematite was determined to a large extent by the polar headgroup. Adsorption of Atrac and PEGMO as a function of concentration showed good agreement with the Freundlich adsorption model, suggesting energetically heterogeneous adsorption. In situ desorption experiments revealed that a large fraction of the Atrac was weakly attached to the hematite surface, as it was partially removed by flushing with water at pH 8.5 and 10. These results suggest that a separate washing unit after the flotation step could be beneficial in reducing the contamination of iron ore by flotation chemicals.

  • 15. Carabante, Ivan
    et al.
    Grahn, Mattias
    Holmgren, Allan
    Hedlund, Jonas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    The influence of Zn2+ ions on the adsorption of arsenate onto ferrihydrite studied by in situ ATR-FTIR spectroscopy2010Konferensbidrag (Övrigt vetenskapligt)
  • 16.
    Carabante, Ivan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Grahn, Mattias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Holmgren, Allan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Kumpiene, Jurate
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Hedlund, Jonas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Adsorption of As (V) on iron oxide nanoparticle films studied by in situ ATR-FTIR spectroscopy2009Ingår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 346, nr 1-3, s. 106-113Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Stabilization of arsenic contaminated soils by iron oxides has been proposed as a remediation technique to prevent leaching of arsenate into the environment. Fundamental studies are needed to establish under which conditions the complexes formed are stable. In the present work, a powerful technique, viz. ATR-FTIR spectroscopy, is adapted to studies of adsorption of arsenate species on iron oxides. This technique facilitates acquisition of both quantitative and qualitative in situ adsorption data.In the present work, about 800 nm thick films of 6-lineferrihydrite were deposited on ZnSe ATR crystals. Arsenate adsorption on the ferrihydrite film was studied at pD values ranging from 4 to 12 and at an arsenate concentration of 0.03 mM in D2O solution. The amount of adsorbed arsenate decreased with increasing pD as a result of the more negatively charged iron oxide surface at higher pD values. The adsorption and desorption kinetics were also studied. Arsenate showed a higher adsorption rate within the first 70 minutes and a much lower adsorption rate from 70 up to 300 minutes. The low adsorption rate at longer reaction times was partly due to a low desorption rate of already adsorbed carbonate species adsorbed at the surface. The desorption of carbonate species was evidenced by the appearance of negative absorption bands. The desorption of adsorbed arsenate complexes was examined by flushing with D2O at pD 4 and 8.5 and it was found that the complexes were very stable at pD 4 suggesting formation of mostly inner-sphere complexes whereas a fraction of the complexes at pD 8.5 were less stable than at pD 4, possibly due to the formation of outer-sphere complexes.In summary, the ATR technique was shown to provide in situ information about the adsorption rate, desorption rate and the speciation of the complexes formed within a single experiment, which is very difficult to obtain using other techniques.

  • 17.
    Carabante, Ivan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Study of arsenate adsorption on iron oxide by in situ ATR-FTIR spectroscopy2009Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Stabilization of arsenic contaminated soils by iron oxides has been proposed as a remediation technique to prevent leaching of arsenate into the environment. However, fundamental studies are needed to establish under which conditions the complexes formed are stable. A new method based on ATR-FTIR spectroscopy was adapted to study the adsorption of arsenate species on iron oxides. The measurements required the use of D2O as solvent. The amount of arsenate complexes adsorbed on the iron oxide increased with decreasing pD in the range studied, viz. pD 4-12. Arsenate complexes adsorbed at pD 4 desorbed from the film to some extent as the pD was increased to 8.5 or 12. The stability of arsenate complexes adsorbed on the iron oxide evidently changed with the change in pD, most likely due to the electrostatic repulsion between the negatively charged oxoanion and the more negatively charged iron oxide as the pD increased. From competitive adsorption experiments it was found that arsenate species were more strongly bonded to the iron oxide than phosphate species. Furthermore, it was found that two different phosphate complexes formed on the iron surface at pD 4, one deuterated and the other one de-deuterated. The complexes showed very different stability. The deuterated phosphate complex was desorbed easily from the iron oxide film as arsenate was added to the system whereas the de-deuterated phosphate complex only desorbed slightly from the film upon adding arsenate.This work has increased the fundamental knowledge of the iron oxide/arsenate/phosphate system, which will be of importance for the development of more effective soil remediation techniques.

  • 18.
    Carabante, Ivan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Kumpiene, Jurate
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik.
    Grahn, Mattias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Holmgren, Allan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    Hedlund, Jonas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Industriell miljö- och processteknik.
    A powerful method for studying the adsorption of As(V) on iron oxides in situ2008Ingår i: Arsenic in the environment - Arsenic from nature to humans: Book of Abstracts, 2008Konferensbidrag (Övrigt vetenskapligt)
1 - 18 av 18
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