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Debromination of Waste Circuit Boards by Reaction in Solid and Liquid Phases: Phenomenological Behavior and Kinetics. Polymers (Basel) 2023; 15:polym15061388. [PMID: 36987169 PMCID: PMC10052934 DOI: 10.3390/polym15061388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/01/2023] [Accepted: 03/08/2023] [Indexed: 03/12/2023] Open
Abstract
The debromination of waste circuit boards (WCBs) used in computer motherboards and components has been studied with two different pieces of equipment. Firstly, the reaction of small particles (around one millimeter in diameter) and larger pieces obtained from WCBs was carried out with several solutions of K2CO3 in small non-stirred batch reactors at 200–225 °C. The kinetics of this heterogeneous reaction has been studied considering both the mass transfer and chemical reaction steps, concluding that the chemical step is much slower than diffusion. Additionally, similar WCBs were debrominated using a planetary ball mill and solid reactants, namely calcined CaO, marble sludge, and calcined marble sludge. A kinetic model has been applied to this reaction, finding that an exponential model is able to explain the results quite satisfactorily. The activity of the marble sludge is about 13% of that of pure CaO and is increased to 29% when slightly calcinating its calcite at only 800 °C for 2 h.
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Grassi M, Colombo I, Manca D, Biasin A, Grassi L, Grassi G, Abrami M. Multiscale mathematical modelling of drug activation by co-grinding. Chem Eng Sci 2022. [DOI: 10.1016/j.ces.2022.118073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Gandon-Ros G, Aracil I, Gómez-Rico MF, Conesa JA. Mechanochemical debromination of waste printed circuit boards with marble sludge in a planetary ball milling process. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 317:115431. [PMID: 35649335 DOI: 10.1016/j.jenvman.2022.115431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/25/2022] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
An effective management of waste printed circuit board (WCB) recycling presents significant advantages of an economic, social, and environmental nature. This is particularly the case when a suitable valorisation is made of the non-metallic parts of the WCBs, well known for their "hidden" toxicological risks. Such benefits motivate research on techniques that could contribute to mitigating their adverse socio-environmental impacts. In this work, waste printed circuit boards (WCBs) containing tetrabromobisphenol A (TBBPA) as a brominated flame retardant (BFR) underwent debromination using a mechanochemical treatment (MCT) and marble sludge, another recoverable waste, as well as pure CaO as additives. All runs in this work were performed at an intermediate rotation speed of 450 rpm, using additive/WCB mass ratios (Rm) of 4:1 and 8:1, ball to powder ratios (BPR) of 20:1 and 50:1, treatment times from 2.5 h to 10 h, two WCB sizes (powder and 0.84 mm) and marble sludge, from original to precalcined conditioning. Stainless steel jars and balls were used to verify the effect of each parameter on the system and to seek an optimum process. Complete debromination of 0.84 mm WCBs was achieved at 450 rpm, using a Rm of 8:1, a BPR of 50:1, a residence time of 10 h (more than 95% in only 5 h), and a precalcined marble sludge as additive. The results revealed that when using a Rm of 4:1 instead of 8:1, more waste could be effectively treated, per batch with a lesser need for additives, at the expense of a slightly lower level of debromination efficiency. In the same way, an appropriate apparent ball diameter (with respect to the volume of the used jar) should be carefully studied in relation to WCB size in order to achieve a beneficial total amount of energy transfer during milling.
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Affiliation(s)
- Gerard Gandon-Ros
- Institute of Chemical Process Engineering, University of Alicante, P.O. Box 99, E-03080, Alicante, Spain; Department of Chemical Engineering, University of Alicante, P.O. Box 99, E-03080, Alicante, Spain
| | - Ignacio Aracil
- Institute of Chemical Process Engineering, University of Alicante, P.O. Box 99, E-03080, Alicante, Spain; Department of Chemical Engineering, University of Alicante, P.O. Box 99, E-03080, Alicante, Spain
| | - María Francisca Gómez-Rico
- Institute of Chemical Process Engineering, University of Alicante, P.O. Box 99, E-03080, Alicante, Spain; Department of Chemical Engineering, University of Alicante, P.O. Box 99, E-03080, Alicante, Spain
| | - Juan A Conesa
- Institute of Chemical Process Engineering, University of Alicante, P.O. Box 99, E-03080, Alicante, Spain; Department of Chemical Engineering, University of Alicante, P.O. Box 99, E-03080, Alicante, Spain.
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Polo A, Carta M, Delogu F, Rustici M, Budroni MA. Controlling Nonlinear Dynamics of Milling Bodies in Mechanochemical Devices Driven by Pendular Forcing. Front Chem 2022; 10:915217. [PMID: 35991610 PMCID: PMC9388739 DOI: 10.3389/fchem.2022.915217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 06/20/2022] [Indexed: 11/26/2022] Open
Abstract
Understanding the dynamics of milling bodies is key to optimize the mixing and the transfer of mechanical energy in mechanochemical processing. In this work, we present a comparative study of mechanochemical reactors driven by harmonic pendular forcing and characterized by different geometries of the lateral borders. We show that the shape of the reactor bases, either flat or curved, along with the size of the milling body and the elasticity of the collisions, represents relevant parameters that govern the dynamical regimes within the system and can control the transition from periodic to chaotic behaviors. We single out possible criteria to preserve target dynamical scenarios when the size of the milling body is changed, by adapting the relative extent of the spatial domain. This allows us to modulate the average energy of the collisions while maintaining the same dynamics and paves the way for a unifying framework to control the dynamical response in different experimental conditions. We finally explore the dynamical and energetic impact of an increasingly asymmetric mechanical force.
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Fe-X-B-Cu (X = Nb, NiZr) Alloys Produced by Mechanical Alloying: Influence of Milling Device. METALS 2021. [DOI: 10.3390/met11030379] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this work, we analyze the influence of the milling device in the microstructural evolution of two Fe-X-B-Cu (X = Nb, NiZr) alloys produced by mechanical alloying (MA). The two milling devices are a planetary mil (P7) and a shaker mill (SPEX 8000). Microstructural analysis by X-ray diffraction detects the formation of a Fe rich solid solution. In the Fe-Nb-B-Cu alloy produced in the shaker mill also appears a Nb(B) minor phase, whereas in the Fe-NiZr-B-Cu alloy produced in the planetary mill, a minor disordered phase is formed. The comparative study regarding the energy transferred per unit of time in both devices determines that the shaker mill is more energetic. This fact explains that in the Fe-Nb-B-Cu alloy, Nb has not been introduced in the main Fe rich phase, whereas in the Fe-NiZr-B-Cu alloy milled in the shaker mill was formed the highly disordered phase. With regard to thermal analysis, the values of the apparent activation energies of the main crystallization process (above 200 kJ/mol) correspond to the crystalline growth of the nanocrystalline Fe rich phase.
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Concas A, Pisu M, Cao G. Mechanochemical immobilization of heavy metals in contaminated soils: A novel mathematical modeling of experimental outcomes. JOURNAL OF HAZARDOUS MATERIALS 2020; 388:121731. [PMID: 31786025 DOI: 10.1016/j.jhazmat.2019.121731] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 11/08/2019] [Accepted: 11/19/2019] [Indexed: 06/10/2023]
Abstract
Mechanochemical processing to immobilize heavy metals in contaminated soils has been proposed few years ago. The corresponding experimental results have shown that, under specific operating conditions, the mechanical energy provided by suitable ball mills, can greatly reduce heavy metals mobility without the addition of any reactant. Such results, together with the extreme simplicity of the proposed technique, are still very promising in view of its industrial transposition. Along these lines, the use of suitable mathematical models might represent a valuable tool which would permit to design and control mechano-chemical reactors for field applications. In this work, a simple albeit exhaustive model is proposed for the first time to quantitatively describe the effects of the dynamics of milling process, such as impact frequency and energy, on the immobilization kinetics. Model results and experimental data obtained so far are successfully compared in terms of leached heavy metals and immobilization efficiency evolution with treatment time. Finally, the potential capability of the model to contribute to the industrial scale transposition of the proposed technique is addressed.
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Affiliation(s)
- Alessandro Concas
- Center for Advanced Studies, Research and Development in Sardinia (CRS4), Loc. Piscina Manna, Building 1, 09050 Pula CA, Italy.
| | - Massimo Pisu
- Center for Advanced Studies, Research and Development in Sardinia (CRS4), Loc. Piscina Manna, Building 1, 09050 Pula CA, Italy
| | - Giacomo Cao
- Interdepartmental Center of Environmental Science and Engineering (CINSA), University of Cagliari, Via San Giorgio 12, 09124 Cagliari, Italy; Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, Via Marengo 2, 09123 Cagliari, Italy
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Mill, material, and process parameters – A mechanistic model for the set-up of wet-stirred media milling processes. ADV POWDER TECHNOL 2019. [DOI: 10.1016/j.apt.2019.04.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Di Nardo T, Moores A. Mechanochemical amorphization of chitin: impact of apparatus material on performance and contamination. Beilstein J Org Chem 2019; 15:1217-1225. [PMID: 31293669 PMCID: PMC6604705 DOI: 10.3762/bjoc.15.119] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 05/14/2019] [Indexed: 12/19/2022] Open
Abstract
Herein, we present a study of the impact of the jar and ball medium on the performance in the mechanochemical amorphization of chitin. We measured the crystallinity index of chitin after milling it in a vibration mill in an apparatus made of copper, aluminum, brass, tungsten carbide, zirconia, stainless steel, polytetrafluoroethylene (PTFE), or poly(methyl methacrylate) (PMMA). These materials offer a range of Vickers hardness values and the impact of these parameters is discussed. The role of the size and mass of the balls is also studied in the case of stainless steel. This study also highlights one of the major challenges during milling, which is contamination of the studied samples.
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Affiliation(s)
- Thomas Di Nardo
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3A 0B8, Canada
| | - Audrey Moores
- Centre in Green Chemistry and Catalysis, Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3A 0B8, Canada
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Predicting effects of operating condition variations on breakage rates in stirred media mills. Chem Eng Res Des 2018. [DOI: 10.1016/j.cherd.2018.09.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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10
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On the Use of JMAK Theory to Describe Mechanical Amorphization: A Comparison between Experiments, Numerical Solutions and Simulations. METALS 2018. [DOI: 10.3390/met8060450] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Affiliation(s)
- Davin Tan
- Department of Chemistry; McGill University; 801 Sherbrooke St.W. H3A0B8 Montreal Canada
| | - Tomislav Friščić
- Department of Chemistry; McGill University; 801 Sherbrooke St.W. H3A0B8 Montreal Canada
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Dynamic impact milling model with a particle-scale breakage kernel. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/b978-0-444-63428-3.50084-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Naik S, Chaudhuri B. Quantifying Dry Milling in Pharmaceutical Processing: A Review on Experimental and Modeling Approaches. J Pharm Sci 2015; 104:2401-13. [PMID: 26096636 DOI: 10.1002/jps.24512] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Revised: 03/21/2015] [Accepted: 04/02/2015] [Indexed: 11/08/2022]
Abstract
Particle size reduction by mechanical means is an important unit operation in the pharmaceutical industry, used to improve flow, solubility, and in amorphization of drugs. It is usually achieved by the fracturing of particles under the action of applied energy. Despite being pervasive in the pharmaceutical field, it is one of the least understood processes owing to the complexity of material and process variables involved during milling. To comprehend the process, efforts should be focused on techniques that measure the particle size as well as the control the process. With the ongoing initiative of US FDA to encourage design in quality, the review is focused on some process analytical tools to characterize particle size distribution as well as process modeling tools to simulate particle size reduction. Additionally, an overview of some fundamental aspects related to milling is provided. To this end, the review is limited, mainly concentrating on some of experimental and modeling approaches used to quantify and understand the physics behind the process of dry milling.
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Affiliation(s)
- Shivangi Naik
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut, 06269
| | - Bodhisattwa Chaudhuri
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut, 06269.,Institute of Material Sciences, University of Connecticut, Storrs, Connecticut, 06269
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15
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Budroni MA, Pilosu V, Delogu F, Rustici M. Multifractal properties of ball milling dynamics. CHAOS (WOODBURY, N.Y.) 2014; 24:023117. [PMID: 24985431 DOI: 10.1063/1.4875259] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This work focuses on the dynamics of a ball inside the reactor of a ball mill. We show that the distribution of collisions at the reactor walls exhibits multifractal properties in a wide region of the parameter space defining the geometrical characteristics of the reactor and the collision elasticity. This feature points to the presence of restricted self-organized zones of the reactor walls where the ball preferentially collides and the mechanical energy is mainly dissipated.
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Affiliation(s)
- M A Budroni
- Dipartimento di Chimica e Farmacia, Università degli Studi di Sassari, Via Vienna 2, Sassari 07100, Italy
| | - V Pilosu
- Dipartimento di Chimica e Farmacia, Università degli Studi di Sassari, Via Vienna 2, Sassari 07100, Italy
| | - F Delogu
- Dipartimento di Ingegneria Meccanica, Chimica, e dei Materiali, Università degli Studi di Cagliari, via Marengo 2, Cagliari 09123, Italy
| | - M Rustici
- Dipartimento di Chimica e Farmacia, Università degli Studi di Sassari, Via Vienna 2, Sassari 07100, Italy
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16
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A Solvent-Free, One-Step, One-Pot Gewald Reaction for Alkyl-aryl Ketones via Mechanochemistry. APPLIED SCIENCES-BASEL 2014. [DOI: 10.3390/app4020171] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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17
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Capece M, Bilgili E, Davé RN. Formulation of a physically motivated specific breakage rate parameter for ball milling via the discrete element method. AIChE J 2014. [DOI: 10.1002/aic.14451] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Maxx Capece
- Otto H. York Dept. of Chemical, Biological, and Pharmaceutical Engineering; New Jersey Institute of Technology; Newark NJ 07102
| | - Ecevit Bilgili
- Otto H. York Dept. of Chemical, Biological, and Pharmaceutical Engineering; New Jersey Institute of Technology; Newark NJ 07102
| | - Rajesh N. Davé
- Otto H. York Dept. of Chemical, Biological, and Pharmaceutical Engineering; New Jersey Institute of Technology; Newark NJ 07102
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Ebadnejad A, Karimi G, Dehghani H. Application of response surface methodology for modeling of ball mills in copper sulphide ore grinding. POWDER TECHNOL 2013. [DOI: 10.1016/j.powtec.2013.04.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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19
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Freireich B, Li J, Litster J, Wassgren C. Incorporating particle flow information from discrete element simulations in population balance models of mixer-coaters. Chem Eng Sci 2011. [DOI: 10.1016/j.ces.2011.04.015] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Prasad DVN, Theuerkauf J. Improvement in the Collision Intensity of Grinding Media in High Energy Impact Mills. Chem Eng Technol 2010. [DOI: 10.1002/ceat.200900392] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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22
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Freireich B, Litster J, Wassgren C. Using the discrete element method to predict collision-scale behavior: A sensitivity analysis. Chem Eng Sci 2009. [DOI: 10.1016/j.ces.2009.04.019] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Prasad DVN, Theuerkauf J. Effect of Grinding Media Size And Chamber Length on Grinding in a Spex Mixer Mill. Chem Eng Technol 2009. [DOI: 10.1002/ceat.200900035] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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FENG PZ, WANG XH, QIANG YH, QU XH. Energy analysis of mechanical alloying of molybdenum disilicide in a new-type high energy vibrating ball mill. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/s1006-1266(08)60093-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Concas A, Montinaro S, Pisu M, Cao G. Mechanochemical remediation of heavy metals contaminated soils: Modelling and experiments. Chem Eng Sci 2007. [DOI: 10.1016/j.ces.2007.02.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Montinaro S, Concas A, Pisu M, Cao G. Remediation of heavy metals contaminated soils by ball milling. CHEMOSPHERE 2007; 67:631-9. [PMID: 17188323 DOI: 10.1016/j.chemosphere.2006.11.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2006] [Revised: 11/02/2006] [Accepted: 11/03/2006] [Indexed: 05/13/2023]
Abstract
In the present work, the use of ball milling reactors for the remediation of lead contaminated soils was investigated. Lead immobilization was achieved without the use of additional reactants but only through the exploitation of weak transformations induced on the treated soil by mechanical loads taking place during collisions among milling media. The degree of metal immobilization was evaluated by analyzing the leachable fraction of Pb(II) obtained through the "synthetic precipitation leaching procedure". The reduction of leachable Pb(II) from certain synthetic soils, i.e., bentonitic, sandy and kaolinitc ones, was obtained under specific milling regimes. For example, for the case of bentonitic soils characterized by a Pb(II) concentration in the solid phase equal to 954.4 mg kg(-1), leachable Pb(II) was reduced, after 7 h of mechanical treatment, from 1.3 mg l(-1) to a concentration lower than the USEPA regulatory threshold (i.e., 0.015 mg l(-1) for drinkable water). Similar results were obtained for sandy and kaolinitic soils. X-ray diffraction, scanning electron microscopy, electron dispersive spectroscopy and granulometric analyses revealed no significant alterations of the intrinsic character of sandy and bentonitic soils after milling except for a relatively small increase of particles size and a partial amorphization of the treated soil. On the other hand, the mechanical treatment caused the total amorphization of kaolinitic soil. The increase of immobilization efficiency can be probably ascribed to specific phenomena induced by mechanical treatment such as entrapment of Pb(II) into aggregates due to aggregation, solid diffusion of Pb(II) into crystalline reticulum of soil particles as well as the formation of new fresh surfaces (through particle breakage) onto which Pb(II) may be irreversibly adsorbed.
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Affiliation(s)
- Selena Montinaro
- Dipartimento di Ingegneria Chimica e Materiali, Università degli Studi di Cagliari and Unità di Ricerca del Consorzio Interuniversitario Nazionale La Chimica per l'Ambiente, Piazza d'Armi, 09123 Cagliari, Italy
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