1
|
Modification of Natural Peat for Removal of Copper Ions from Aqueous Solutions. WATER 2022. [DOI: 10.3390/w14132114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study aimed at estimating peat adsorption properties for copper ion removal from aqueous solutions during peat modification. Two peat modifications have been studied using batch tests and quantitatively reproduced with instrumental analysis by using spectrometric, potentiometric, and thermodynamic modeling methods. The first variation—mechanical activation—was carried out in a planetary mill; for the second one—mechanochemical activation—dry sodium percarbonate (Na2CO3∙1.5H2O2) was added. The adsorption of copper ions was studied in the concentration range from 10–150 mg/L with an interaction time from 0.25–12 h. Both modifications led to significant changes in the interaction energy in the adsorption layer; thus, the acceptor properties of macromolecules were enhanced from natural peat to mechanically activated peat and mechanochemically activated peat. FTIR spectra, specific surface area characteristics, and sorption experiments show the predominantly chemical nature of copper sorption. Maximum adsorption capacity was determined to be 24.1, 42.1, and 16.0 mg/g for natural peat, mechanically activated peat, and mechanochemically activated peat, respectively. The example of peat mechanochemically oxidized with Na2CO3∙1.5H2O2 shows that the improvement in the physicochemical properties (CBET and specific surface area) plays a smaller role in the sorption capacity in relation to copper ions than the presence of phenolic and carboxyl groups, the content of which decreases during oxidation.
Collapse
|
2
|
Velasco CA, Brearley AJ, Gonzalez-Estrella J, Ali AMS, Meza MI, Cabaniss SE, Thomson BM, Forbes TZ, Lezama Pacheco JS, Cerrato JM. From Adsorption to Precipitation of U(VI): What is the Role of pH and Natural Organic Matter? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:16246-16256. [PMID: 34797046 PMCID: PMC8680647 DOI: 10.1021/acs.est.1c05429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We investigated interfacial reactions of U(VI) in the presence of Suwannee River natural organic matter (NOM) at acidic and neutral pH. Laboratory batch experiments show that the adsorption and precipitation of U(VI) in the presence of NOM occur at pH 2 and pH 4, while the aqueous complexation of U by dissolved organic matter is favored at pH 7, preventing its precipitation. Spectroscopic analyses indicate that U(VI) is mainly adsorbed to the particulate organic matter at pH 4. However, U(VI)-bearing ultrafine to nanocrystalline solids were identified at pH 4 by electron microscopy. This study shows the promotion of U(VI) precipitation by NOM at low pH which may be relevant to the formation of mineralized deposits, radioactive waste repositories, wetlands, and other U- and organic-rich environmental systems.
Collapse
Affiliation(s)
- Carmen A Velasco
- Department of Civil, Construction and Environmental Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Adrian J Brearley
- Department of Earth and Planetary Sciences, MSC03 2040, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Jorge Gonzalez-Estrella
- School of Civil and Environmental Engineering, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - Abdul-Mehdi S Ali
- Department of Earth and Planetary Sciences, MSC03 2040, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - María Isabel Meza
- Department of Civil, Construction and Environmental Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Stephen E Cabaniss
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Bruce M Thomson
- Department of Civil, Construction and Environmental Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Tori Z Forbes
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Juan S Lezama Pacheco
- Department of Earth System Science, Stanford University, Stanford, California 94305, United States
| | - José M Cerrato
- Department of Civil, Construction and Environmental Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
| |
Collapse
|
3
|
Velasco CA, Artyushkova K, Ali AMS, Osburn CL, Gonzalez-Estrella J, Lezama-Pacheco JS, Cabaniss SE, Cerrato JM. Organic Functional Group Chemistry in Mineralized Deposits Containing U(IV) and U(VI) from the Jackpile Mine in New Mexico. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:5758-5767. [PMID: 30998849 PMCID: PMC6557721 DOI: 10.1021/acs.est.9b00407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We investigated the functional group chemistry of natural organic matter (NOM) associated with both U(IV) and U(VI) in solids from mineralized deposits exposed to oxidizing conditions from the Jackpile Mine, Laguna Pueblo, NM. The uranium (U) content in unreacted samples was 0.44-2.6% by weight determined by X-ray fluorescence. In spite of prolonged exposure to ambient oxidizing conditions, ≈49% of U(IV) and ≈51% of U(VI) were identified on U LIII edge extended X-ray absorption fine structure spectra. Loss on ignition and thermogravimetric analyses identified from 13% to 44% of NOM in the samples. Carbonyl, phenolic, and carboxylic functional groups in the unreacted samples were identified by fitting of high-resolution X-ray photoelectron spectroscopy (XPS) C 1s and O 1s spectra. Peaks corresponding to phenolic and carbonyl functional groups had intensities higher than those corresponding to carboxylic groups in samples from the supernatant from batch extractions conducted at pH 13, 7, and 2. U(IV) and U(VI) species were detected in the supernatant after batch extractions conducted under oxidizing conditions by fitting of high-resolution XPS U 4f spectra. The outcomes from this study highlight the importance of the influence of pH on the organic functional group chemistry and U speciation in mineralized deposits.
Collapse
Affiliation(s)
- Carmen A. Velasco
- Department of Civil, Construction & Environmental Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Kateryna Artyushkova
- Department of Chemical and Biological Engineering, MSC01 1120, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Abdul-Mehdi S. Ali
- Department of Earth and Planetary Sciences, MSC03 2040, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Christopher L. Osburn
- Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, North Carolina 27607, United States
| | - Jorge Gonzalez-Estrella
- Department of Civil, Construction & Environmental Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Juan S. Lezama-Pacheco
- Department of Environmental Earth System Science, Stanford University, Stanford, California 94305, United States
| | - Stephen E. Cabaniss
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - José M. Cerrato
- Department of Civil, Construction & Environmental Engineering, MSC01 1070, University of New Mexico, Albuquerque, New Mexico 87131, United States
- Corresponding Author. Telephone: (001) (505) 277-0870. Fax: (001) (505) 277-1918
| |
Collapse
|
4
|
Bordelet G, Beaucaire C, Phrommavanh V, Descostes M. Chemical reactivity of natural peat towards U and Ra. CHEMOSPHERE 2018; 202:651-660. [PMID: 29602097 DOI: 10.1016/j.chemosphere.2018.03.140] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 03/15/2018] [Accepted: 03/20/2018] [Indexed: 06/08/2023]
Abstract
Peat is a complex material with several organic constituents that contribute to its high capacity to retain metals. In the context of uranium mining, peat can accumulate high concentrations of uranium and its decay products such as radium. Hence, interaction with peat appears to be a key factor in the understanding of the geochemical mechanisms controlling the fate of these products. This study aims to determine the sorption properties of two trace elements, U(VI) and 226Ra, on natural organic matter from peat. The presented method was applied to both natural peat samples originating from a mining context, with various contents of organic matter (from 40 to 70%) and detrital loads, and wetland peat with a more than 98% composition of organic matter. In the present study, considering peat material as a sorbent, its reactivity towards metals and other contaminants can be described as that of an ion-exchanger. A relatively simple model of ion-exchange based on the sorption properties of carboxylic sites has been applied with success to describe the sorption of uranium and radium. In the general overview of the different mechanisms able to control the mobility of these radionuclides in a uranium mining context, organic matter is likely one of the main contributors to radionuclide scavenging even under oxic conditions.
Collapse
Affiliation(s)
- G Bordelet
- CEA Saclay, DEN/DANS/DPC/SECR/L3MR, Bât: 450, F-91191 Gif-sur-Yvette, France
| | - C Beaucaire
- CEA Saclay, DEN/DANS/DPC/SECR/L3MR, Bât: 450, F-91191 Gif-sur-Yvette, France
| | - V Phrommavanh
- ORANO Mining, R&D Dpt, BAL 4246D-3, Tour AREVA - 1, Place Jean Millier 92084 Paris la Defense Cedex, France
| | - M Descostes
- ORANO Mining, R&D Dpt, BAL 4246D-3, Tour AREVA - 1, Place Jean Millier 92084 Paris la Defense Cedex, France.
| |
Collapse
|
5
|
Tserenpil S, Maslov OD, Norov N, Liu QC, Fillipov MF, Theng BKG, Belov AG. Chemical and mineralogical composition of the Mongolian rural soils and their uranium sorption behavior. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2013; 118:105-112. [PMID: 23295620 DOI: 10.1016/j.jenvrad.2012.11.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Revised: 11/05/2012] [Accepted: 11/29/2012] [Indexed: 06/01/2023]
Abstract
Distribution of uranium (VI) between soil solids and solutions is a key parameter in assessing the risk to the biosphere of disposing uranium-rich waste products from nuclear plants as well as uranium (U) ore mining. Both of these topics have recently been brought to public attention in Mongolia. Regional background levels of soil elements are an important dataset for accessing the actual environmental situation and monitoring pollution levels. Little information, however, is available on background concentrations of various elements in Mongolian soils. Thirteen rural soils were sampled from six provinces in Mongolia, and the concentrations of macro-, micro- and trace elements were measured. The values obtained served as a reference (baseline) for uncontaminated soils. The soils were characterized with slightly acidic to strongly alkaline pH values. With the exception of the sample from a western province, all the soils investigated contained little organic matter. The content of soil elements did not vary widely among geographical regions. The concentration of most micro elements was within the range of worldwide soil values but the value for Zn tended to be moderately higher. The U (VI) sorption into the soils was investigated using the batch technique and the (237)U radionuclide tracer, produced by the photo fission reaction (238)U(γ, n) (237)U at an electron accelerator. The (237)U distribution coefficient (K(d)), derived from the sorption isotherms, was related to solution pH and varying from 9 to 2547 mL g(-1) when the pH ranged between 3 and 7.7. The sorption process was interpreted in terms of the formation of different U (VI) species at given concentrations, calculated using the Speciation program with and without carbonate in the system. The U sorption isotherm displayed two general patterns: one where sorption decreased as solution pH increased, showing a maximum at pH 3, and another pattern revealed an adsorption maximum at pH 5 and then decreased up to pH 7.7 (the final solution pH). The observed decrease in K(d) when solution pH increased from 6 to 8 was consistent with the increased formation of soluble UO(2)(OH)(2) species. A linear negative correlation between lgK(d) and the solution pH was observed similarly to that reported for the soils with a pH ≥ 6.
Collapse
Affiliation(s)
- Sh Tserenpil
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, 46 Guanshui Lu, Guiyang, China.
| | | | | | | | | | | | | |
Collapse
|
6
|
Filippov MF, Maslov OD, Bozhikov GA, Tserenpil S, Gustova MV, Milanov MV. Sorption of U(VI) with soil from the region of location of the Novi Khan radioactive waste repository in Bulgaria. RADIOCHEMISTRY 2009. [DOI: 10.1134/s1066362209010172] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|