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Burgos-Ruiz M, Ilett M, Roncal-Herrero T, Elert K, Rubio-Domene R, Ruiz-Agudo E, Rodriguez-Navarro C. Bio-Inspired Fluorescent Calcium Sulfate for the Conservation of Gypsum Plasterwork. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2402581. [PMID: 38940389 DOI: 10.1002/smll.202402581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 06/11/2024] [Indexed: 06/29/2024]
Abstract
In this work, the potential of bio-inspired strategies for the synthesis of calcium sulfate (CaSO4·nH2O) materials for heritage conservation is explored. For this, a nonclassical multi-step crystallization mechanism to understand the effect of calcein- a fluorescent chelating agent with a high affinity for divalent cations- on the nucleation and growth of calcium sulfate phases is proposed. Moving from the nano- to the macro-scale, this strategy sets the basis for the design and production of fluorescent nano-bassanite (NB-C; CaSO4·0.5H2O), with application as a fully compatible consolidant for the conservation of historic plasterwork. Once applied to gypsum (CaSO4·2H2O) plaster specimens, cementation upon hydration of nano-bassanite results in a significant increase in mechanical strength, while intracrystalline occlusion of calcein in newly-formed gypsum cement improves its weathering resistance. Furthermore, under UV irradiation, the luminescence produced by calcein molecules occluded in gypsum crystals formed upon nano-bassanite hydration allows the easy identification of the newly deposited consolidant within the treated gypsum plaster without altering the substrate's appearance.
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Affiliation(s)
- Miguel Burgos-Ruiz
- Department of Mineralogy and Petrology, Faculty of Sciences, University of Granada, Avenida Fuentenueva S/N, Granada, 18002, Spain
| | - Martha Ilett
- School of Chemical and Process Engineering, University of Leeds, Woodhouse, Leeds, LS2 9JT, UK
| | - Teresa Roncal-Herrero
- School of Chemical and Process Engineering, University of Leeds, Woodhouse, Leeds, LS2 9JT, UK
| | - Kerstin Elert
- Department of Mineralogy and Petrology, Faculty of Sciences, University of Granada, Avenida Fuentenueva S/N, Granada, 18002, Spain
- Escuela de Estudios Árabes, Spanish National Research Council (CSIC), Cuesta del Chapiz 22, Granada, 18010, Spain
| | - Ramon Rubio-Domene
- Conservation Department, Council of the Alhambra and Generalife, Calle Real de la Alhambra S/N, Granada, E-18009, Spain
| | - Encarnacion Ruiz-Agudo
- Department of Mineralogy and Petrology, Faculty of Sciences, University of Granada, Avenida Fuentenueva S/N, Granada, 18002, Spain
| | - Carlos Rodriguez-Navarro
- Department of Mineralogy and Petrology, Faculty of Sciences, University of Granada, Avenida Fuentenueva S/N, Granada, 18002, Spain
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Burgos-Ruiz M, Elert K, Ruiz-Agudo E, Cölfen H, Rodriguez-Navarro C. Silica-Functionalized Nanolimes for the Conservation of Stone Heritage. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2300596. [PMID: 37072886 DOI: 10.1002/smll.202300596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/25/2023] [Indexed: 05/03/2023]
Abstract
The relatively recent development of nanolimes (i.e., alcoholic dispersions of Ca(OH)2 nanoparticles) has paved the way for new approaches to the conservation of important art works. Despite their many benefits, nanolimes have shown limited reactivity, back-migration, poor penetration, and lack of proper bonding to silicate substrates. In this work a novel solvothermal synthesis process is presented by which extremely reactive nanostructured Ca(OH)2 particles are obtained using calcium ethoxide as the main precursor species. Moreover, it is demonstrated that this material can be easily functionalized with silica-gel derivatives under mild synthesis conditions, thereby preventing particle growth, increasing total specific surface area, enhancing reactivity, modifying colloidal behavior, and functioning as self-integrated coupling agents. Additionally, the formation of calcium silicate hydrate (CSH) nanocement is promoted by the presence of water, resulting in optimal bonding when applied to silicate substrates, as evidenced by the higher reinforcement effect produced on treated Prague sandstone specimens as compared to those consolidated with nonfunctionalized commercial nanolime. The functionalization of nanolimes is not only a promising strategy for the design of optimized consolidation treatments for the cultural heritage, but may also have important implications for the development of advanced nanomaterials for building, environmental, or biomedical applications.
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Affiliation(s)
- Miguel Burgos-Ruiz
- Department of Mineralogy and Petrology, University of Granada, Av. Fuentenueva s/n, Granada, 18002, Spain
| | - Kerstin Elert
- Department of Mineralogy and Petrology, University of Granada, Av. Fuentenueva s/n, Granada, 18002, Spain
| | - Encarnacion Ruiz-Agudo
- Department of Mineralogy and Petrology, University of Granada, Av. Fuentenueva s/n, Granada, 18002, Spain
| | - Helmut Cölfen
- Physical Chemistry, Department of Chemistry, University of Konstanz, Universitätsstraße 10, D78457, Konstanz, Germany
| | - Carlos Rodriguez-Navarro
- Department of Mineralogy and Petrology, University of Granada, Av. Fuentenueva s/n, Granada, 18002, Spain
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Zhu J, Ding J, Li Y, Wang Q, Yang F, Jia C, Zhang Y, Zhao X, Dong W, Wang J, Lu Z, Li X. Realizing Nanolime Aqueous Dispersion via Ionic Liquid Surface Modification to Consolidate Stone Relics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023. [PMID: 37422798 DOI: 10.1021/acs.langmuir.3c01147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
After decades of research in the conservation of cultural heritage, nanolime (NL) has emerged as a potential alternative inorganic material to the frequently used organic materials. However, its poor kinetic stability in water has been a major challenge that restricted its penetration depth through cultural relics and resulted in unsatisfactory conservation outcomes. Here, for the first time, we realize NL water dispersion by modification of ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) via a sample aqueous solution deposit method. Our findings indicate that the cation of the ionic liquid (IL) binds strongly to the surface of NL particles (IL-NL) by forming hydrogen bonds with Ca(OH)2 facets. The absorption of IL causes an unexpected significant alteration in the morphology of NL particles and results in a drastic reduction in NL's size. More importantly, this absorption endows NL excellent kinetic stability dispersed into water and implements NL water dispersion, which makes a breakthrough in terms of extreme poor kinetic stability of as-synthesized NL and commercial NL in water. The mechanism driving IL-NL water dispersion is explained by Stern theory. In the context of consolidating weathered stone, the presence of IL may delay carbonation of NL but the penetration depth of IL-NL through stone samples is three times deeper than that of as-synthesized and commercial NLs. Additionally, the consolidation strength of IL-NL is similar to that of as-synthesized NL and commercial NL. Moreover, IL-NL has no significant impact on the permeability, pore size, and microstructure of consolidated stone relics. Our research contributes to the field of NL-related materials and will enhance the dissemination and utilization of NL-based materials in the preservation of water-insensitive cultural heritage.
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Affiliation(s)
- Jinmeng Zhu
- NPU Institute of Culture and Heritage, Key Laboratory of Archaeological Exploration and Cultural Heritage Conservation Technology (NPU), Ministry of Education, Northwestern Polytechnical University, Xi'an 710072, China
- Key Scientific Research Base of Conservation & Restoration for Mural as Collection and Materials Science in State Administration of Cultural Heritage, Xi'an 710061, China
| | - Jinghan Ding
- State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Lab of Graphene (NPU), Xi'an 710072, China
| | - Yuke Li
- Department of Chemistry and Centre for Scientific Modeling and Computation, Chinese University of Hong Kong, Shatin, Hong Kong 999077, China
| | - Qi Wang
- State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Lab of Graphene (NPU), Xi'an 710072, China
| | - Fan Yang
- State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Lab of Graphene (NPU), Xi'an 710072, China
| | - Cong Jia
- School of Materials and Chemical Engineering, Xi'an Technological University, Xi'an 710021, P. R. China
| | - Yaxu Zhang
- Shaanxi Provincial Institute of Archaeology, Xi'an 710054, China
| | - Xichen Zhao
- Shaanxi Provincial Institute of Archaeology, Xi'an 710054, China
| | - Wenqiang Dong
- NPU Institute of Culture and Heritage, Key Laboratory of Archaeological Exploration and Cultural Heritage Conservation Technology (NPU), Ministry of Education, Northwestern Polytechnical University, Xi'an 710072, China
| | - Jia Wang
- Center for Wall Painting Protection, Shaanxi History Museum, Xi'an 710061, China
| | - Zhiyong Lu
- Center for Wall Painting Protection, Shaanxi History Museum, Xi'an 710061, China
| | - Xuanhua Li
- NPU Institute of Culture and Heritage, Key Laboratory of Archaeological Exploration and Cultural Heritage Conservation Technology (NPU), Ministry of Education, Northwestern Polytechnical University, Xi'an 710072, China
- Gansu Provincial Research Center for Conservation of Dunhuang Cultural Heritage, Dunhuang 736200, China
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Rodriguez-Navarro C, Monasterio-Guillot L, Burgos-Ruiz M, Ruiz-Agudo E, Elert K. Unveiling the secret of ancient Maya masons: Biomimetic lime plasters with plant extracts. SCIENCE ADVANCES 2023; 9:eadf6138. [PMID: 37075113 PMCID: PMC10115411 DOI: 10.1126/sciadv.adf6138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Ancient Maya produced some of the most durable lime plasters on Earth, yet how this was achieved remains a secret. Here, we show that ancient Maya plasters from Copan (Honduras) include organics and have a calcite cement with meso-to-nanostructural features matching those of calcite biominerals (e.g., shells). To test the hypothesis that the organics could play a similar toughening role as (bio)macromolecules in calcium carbonate biominerals, we prepared plaster replicas adding polysaccharide-rich bark extracts from Copan's local trees following an ancient Maya building tradition. We show that the replicas display similar features as the organics-containing ancient Maya plasters and demonstrate that, as in biominerals, in both cases, their calcite cement includes inter- and intracrystalline organics that impart a marked plastic behavior and enhanced toughness while increasing weathering resistance. Apparently, the lime technology developed by ancient Maya, and likely other ancient civilizations that used natural organic additives to prepare lime plasters, fortuitously exploited a biomimetic route for improving carbonate binders performance.
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A Multi-Analytical Investigation of Roman Frescoes from Rapoltu Mare (Romania). COATINGS 2022. [DOI: 10.3390/coatings12040530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
(1) Background: Due to the precarious situation of many monuments or archeological sites, analytical investigations are necessary to obtain information about the used materials, as well as to identify the most appropriate solutions for their conservation/restoration. This paper addresses the characterization of mural painting fragments collected during the excavation in 2018 in Rapoltu Mare (La vie), Deva. (2) Methods: Specific analytical techniques were used, as follows: X-ray diffractometry (XRD), wavelength dispersive X-ray fluorescence (WDXRF), optical microscopy (OM), zoom microscopy and scanning electron microscopy (SEM), spectroscopic techniques (UV–Vis, FTIR, Raman), porosity and thermal analysis, all of which provide information about the structure, chemical composition, morphology and topography of pigments and their deterioration as well. (3) Results: Up to seven different pigments were identified: Egyptian blue, carbon, calcite, gypsum, hematite, goethite and green earth. Egyptian Blue is identified in all the other color areas, except the white area: in the green zone (as degradation product with beeswax) and in the red zone (in mixture with ochre) too. In addition, carbon and beeswax were highlighted as toner and binder for pigments, respectively. In the presence of the organic beeswax binding environment, the Egyptian blue pigment particles darkened or turned yellow significantly, changing the blue to a greenish color. It is also possible to identify wollastonite (CaSiO3) in the blue pigment, which indicates that the temperature used in the manufacturing of Egyptian blue was higher than 950 °C from thermal analysis. The presence of apatite, hematite and gypsum deposits in the Hunedoara region certifies that these pigments could have been of local origin, as demonstrated by the presence of analytically identified elements (Fe, P, S, Ca). (4) Conclusions: The analytical techniques used for such investigations have highlighted the main pigments used in Roman times for various Roman murals.
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Zhu J, Jia C, Li Y, Zhang P, Ding J, Xu G, Zhao X, Li X. Polydopamine-Modified Nanolime with High Kinetic Stability in Water for the Consolidation of Stone Relics. ACS APPLIED MATERIALS & INTERFACES 2022; 14:13622-13630. [PMID: 35275613 DOI: 10.1021/acsami.1c24699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
As a promising inorganic nanomaterial for the conservation of arenaceous sandstone-based relics such as wall painting, ancient building, stone heritage etc., nanolime (NL) has drawn increasing attention in recent years. Usually, NL needs to be dispersed into an alcoholic solution when applied. Nevertheless, a back-migration phenomenon of NL to the surface of the stone and delayed carbonation of NL enabled by alcohol do not guarantee good preservation effects. Dispersing NL into water can avoid the above issues. However, NL water suspension shows extremely poor kinetic stability, greatly restricting the penetration of NL into stone relics as well as bringing unfavorable impacts to the treated stone heritage. Here, we develop a facile method to synthesize polydopamine (PDA)-modified NL (PDA@NL). Characterizations demonstrate that PDA is uniformly distributed on the surface of NL particles though hydrogen bonds. In addition, the presence of PDA reduces the size of NL particles and achieves the highest specific surface area of NL reported to date. More importantly, water suspension of PDA@NL is far more stable than that of pure NL. The kinetic stability mechanism of PDA@NL in water is attributed to the lessened spatial interactions between NL particles, which is realized by the coverage of PDA on the surface of NL particles. Furthermore, the coverage of PDA does not inhibit carbonation. Within 105 h, NL in PDA@NL completes carbonation and obtains 93.7% calcite, which is comparable to that of NL suspension. Permeability tests prove that the PDA@NL suspension penetrates far deeper through stone specimens compared with the NL suspension. Additionally, PDA@NL presents good consolidation performances for stone samples. Our work opens a new direction for the modification of NL that will boost the studies of NL-modified materials as well as the conservation of cultural heritage.
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Affiliation(s)
- Jinmeng Zhu
- School of Materials and Chemical Engineering, Xi'an Technological University, Xi'an 710021, P. R. China
- Gansu Provincial Research Center for Conservation of Dunhang Cultural Heritage, Dunhuang 736200, China
| | - Cong Jia
- School of Materials and Chemical Engineering, Xi'an Technological University, Xi'an 710021, P. R. China
| | - Yuke Li
- Department of Chemistry and Centre for Scientific Modeling and Computation, Chinese University of Hong Kong, Shatin, Hong Kong 999077, China
| | - Peiyao Zhang
- State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Lab of Graphene (NPU), Xi'an 710072, China
| | - Jinghan Ding
- State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Lab of Graphene (NPU), Xi'an 710072, China
| | - Gang Xu
- School of Materials and Chemical Engineering, Xi'an Technological University, Xi'an 710021, P. R. China
| | - Xichen Zhao
- Shaanxi Provincial Institute of Archaeology, Xi'an 710054, China
| | - Xuanhua Li
- State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Lab of Graphene (NPU), Xi'an 710072, China
- Research & Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen 518057, Guangdong, China
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Mucilages from Different Plant Species Affect the Characteristics of Bio-Mortars for Restoration. COATINGS 2021. [DOI: 10.3390/coatings11010075] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The need for compatible materials for the preservation of cultural heritage has resulted in the revival of lime-based mortar technology and other applications. This work investigates the cohesion and integrity of lime mortars added with fresh mucilage extracted from five plants and evaluates their bioreceptivity for long-term durability. Specimens of lime mortars added with 2.5% of fresh mucilage extracted from Aloe vera, Cylindropuntia californica, Opuntia engelmannii, Opuntia ficus-indica and Salvia hispanica mucilages were analyzed for color change (colorimetry), cohesion (ultrasound measurements), integrity (X-rays) and bioreceptivity (microbiological tests).The internal structure of the specimens added with Cacti mucilages shows better compactness, and no color change was noticed in the bio-mortars also after aging. The bioreceptivity response of mortars inoculated with bacteria, fungi and a photosynthetic biofilm was quite different. Specimens added with Aloe and Cylindropuntia mucilages showed a higher extent of bioreceptivity than the control; the specimens of bio-mortars added with Opuntia engelmannii, Opuntia ficus-indica and Salvia hispanica mucilages did not appear, up to threemonths after the contamination, any microbial growth. These results indicate that the addition of mucilage improves the mortar qualities, but the choice of the plant mucilage must be carefully evaluated since it can be responsible for changes in the bioreceptivity of the mortar.
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Zhu J, Li X, Zhang Y, Wang J, Cao Y, Camaiti M, Wei B. Dual Functionalities of Few-Layered Boron Nitrides in the Design and Implementation of Ca(OH) 2 Nanomaterials toward an Efficient Wall Painting Fireproofing and Consolidation. ACS APPLIED MATERIALS & INTERFACES 2019; 11:11792-11799. [PMID: 30821952 DOI: 10.1021/acsami.9b00826] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Preserving ancient wall paintings from damage has become a challenge over the years. Nanosized calcium hydroxide (Ca(OH)2) has been identified as a promising material to preserve wall paintings. However, the synthesis of nanosized Ca(OH)2 is extremely difficult. Here, we demonstrate a breakthrough in wall painting protection enabled by boron nitride nanosheets (BNNSs) through strategic synthesis Ca(OH)2-BNNS nanohybrids using an aqueous method. The BNNS have two significant functionalities in the design and implementation of the Ca(OH)2 nanomaterials. First, the introduction of BNNS results in the successful synthesis of uniform and nanosized Ca(OH)2 (∼80 nm) in the nanohybrids, which can be attributed to the supersaturation-induced "etching-stripping" mechanism. More interestingly and importantly, a unique gradient penetration structure is strategically formed when applying Ca(OH)2-BNNS hybrids on the wall paintings, i.e., the BNNS-rich layer will be at the surface of wall painting, whereas Ca(OH)2 nanomaterials prefer to penetrate deep in to the wall paintings. This gradient structure will allow the BNNS-rich layer to protect the wall paintings from fire, which is the first report to date among the protection materials for wall paintings; at the same time, nanosized Ca(OH)2 shows superior wall painting consolidation strength compared to commercial Ca(OH)2 material. These results endow new applications of the newly emerging two-dimensional nanomaterials for protecting cultural heritage.
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Affiliation(s)
- Jinmeng Zhu
- State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering , Northwestern Polytechnical University and Shaanxi Joint Lab of Graphene (NPU) , Xi'an 710072 , China
| | - Xuanhua Li
- State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering , Northwestern Polytechnical University and Shaanxi Joint Lab of Graphene (NPU) , Xi'an 710072 , China
| | - Yuanyuan Zhang
- State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering , Northwestern Polytechnical University and Shaanxi Joint Lab of Graphene (NPU) , Xi'an 710072 , China
| | - Jia Wang
- Center for Wall Painting Protection, Shaanxi History Museum , Xi'an 710061 , China
| | - Yijian Cao
- Department of Chemistry , University of Florence , Via della Lastruccia 3-13 , 50019 Sesto Fiorentino , FI , Italy
| | - Mara Camaiti
- CNR-Institute of Geosciences and Earth Resources , Via Giorgio La Pira 4 , 50121 Florence , Italy
| | - Bingqing Wei
- State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering , Northwestern Polytechnical University and Shaanxi Joint Lab of Graphene (NPU) , Xi'an 710072 , China
- Department of Mechanical Engineering , University of Delaware , Newark , Delaware 19716 , United States
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Wei Y, Liu Y. Study of dispersion mechanisms of modified SiC powder: electrostatic repulsion and steric hindrance mechanism. NEW J CHEM 2019. [DOI: 10.1039/c9nj02131k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Surface modification technology was used to increase the dispersion of SiC powder.
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Affiliation(s)
- Yanan Wei
- College of Sciences
- Hebei University of Science and Technology
- Shijiazhuang 050018
- P. R. China
| | - Youxing Liu
- Beijing Key Laboratory of Electrochemical Process and Technology for Materials
- Beijing University of Chemical Technology
- Beijing 100029
- P. R. China
- Institute of Chemistry
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Shi Q, Sterbinsky GE, Prigiobbe V, Meng X. Mechanistic Study of Lead Adsorption on Activated Carbon. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:13565-13573. [PMID: 30350696 DOI: 10.1021/acs.langmuir.8b03096] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Activated carbon (AC) is a carbonaceous material broadly applied in filters to remove lead (Pb(II)) from drinking water through adsorption. However, the chemical interactions between Pb(II) and the reactive sites on AC or other carbonaceous materials are not well understood, yet. The understanding of the mechanism of Pb(II) adsorption onto AC would allow to optimally design AC-based materials even in the presence of a complex liquid phase. Here, the interaction between Pb(II) and functional groups on AC was investigated at the molecular scale to help identifying the chemical reactions at the solid-liquid interface. Spectroscopic analyses and chemical quantum calculations were performed and indicated the formation of monodentate mononuclear Pb(II)-phenol and bidentate mononuclear Pb(II)-carboxyl complexes on AC. Competitive adsorption behavior was observed between Pb(II) and calcium (Ca(II)) because of their similar adsorption configurations on AC. In contrast, anions, including sulfate and phosphate, were observed to enhance Pb(II) adsorption on AC by forming ternary complexes. On the basis of these observations, a new surface complexation model of Pb(II) adsorption onto AC was formulated and validated with batch tests. Overall, this work presents a new set of chemical reactions at the solid-liquid interface between Pb(II) and AC under various conditions of interest for the application of AC or other carbonaceous materials in water treatment.
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Affiliation(s)
- Qiantao Shi
- Center for Environmental Systems , Stevens Institute of Technology , Hoboken , New Jersey 07030 , United States
| | - George E Sterbinsky
- Advanced Photon Source , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - Valentina Prigiobbe
- Center for Environmental Systems , Stevens Institute of Technology , Hoboken , New Jersey 07030 , United States
| | - Xiaoguang Meng
- Center for Environmental Systems , Stevens Institute of Technology , Hoboken , New Jersey 07030 , United States
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