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Ostervold L, Smerigan A, Liu MJ, Filardi LR, Vila FD, Perez-Aguilar JE, Hong J, Tarpeh WA, Hoffman AS, Greenlee LF, Clark EL, Janik MJ, Bare SR. Cation Incorporation into Copper Oxide Lattice at Highly Oxidizing Potentials. ACS Appl Mater Interfaces 2023; 15:47025-47036. [PMID: 37756387 DOI: 10.1021/acsami.3c10296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
Electrolyte cations can have significant effects on the kinetics and selectivity of electrocatalytic reactions. We show an atypical mechanism through which electrolyte cations can impact electrocatalyst performance─direct incorporation of the cation into the oxide electrocatalyst lattice. We investigate the transformations of copper electrodes in alkaline electrochemistry through operando X-ray absorption spectroscopy in KOH and Ba(OH)2 electrolytes. In KOH electrolytes, both the near-edge structure and extended fine-structure agree with previous studies; however, the X-ray absorption spectra vary greatly in Ba(OH)2 electrolytes. Through a combination of electronic structure modeling, near-edge simulation, and postreaction characterization, we propose that Ba2+ cations are directly incorporated into the lattice and form an ordered BaCuO2 phase at potentials more oxidizing than 200 mV vs the normal hydrogen electrode (NHE). BaCuO2 formation is followed by further oxidation to a bulk Cu3+-like BaxCuyOz phase at 900 mV vs NHE. Additionally, during reduction in Ba(OH)2 electrolyte, we find both Cu-O bonds and Cu-Ba scattering persist at potentials as low as -400 mV vs NHE. To our knowledge, this is the first evidence for direct oxidative incorporation of an electrolyte cation into the bulk lattice to form a mixed oxide electrode. The oxidative incorporation of electrolyte cations to form mixed oxides could open a new route for the in situ formation of active and selective oxidation electrocatalysts.
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Affiliation(s)
- Lars Ostervold
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Adam Smerigan
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Matthew J Liu
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
| | - Leah R Filardi
- Department of Chemical Engineering, University of California, Davis, Davis, California 95616, United States
| | - Fernando D Vila
- Department of Physics, University of Washington, Seattle, Washington 98195, United States
| | - Jorge E Perez-Aguilar
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Jiyun Hong
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - William A Tarpeh
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
| | - Adam S Hoffman
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Lauren F Greenlee
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Ezra Lee Clark
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Michael J Janik
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Simon R Bare
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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Hackett C, Abolhassani M, Greenlee LF, Thompson AK. Ultrafiltration Membranes Functionalized with Copper Oxide and Zwitterions for Fouling Resistance. Membranes (Basel) 2022; 12:544. [PMID: 35629870 PMCID: PMC9145826 DOI: 10.3390/membranes12050544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/16/2022] [Accepted: 05/20/2022] [Indexed: 01/25/2023]
Abstract
Polymeric membrane fouling is a long-standing challenge for water filtration. Metal/metal oxide nanoparticle functionalization of the membrane surface can impart anti-fouling properties through the reactivity of the metal species and the generation of radical species. Copper oxide nanoparticles (CuO NPs) are effective at reducing organic fouling when used in conjunction with hydrogen peroxide, but leaching of copper ions from the membrane has been observed, which can hinder the longevity of the CuO NP activity at the membrane surface. Zwitterions can reduce organic fouling and stabilize NP attachment, suggesting a potential opportunity to combine the two functionalizations. Here, we coated polyethersulfone (PES) ultrafiltration membranes with polydopamine (PDA) and attached the zwitterionic compound, thiolated 2-methacryloyloxyethyl phosphorylcholine (MPC-SH), and CuO NPs. Functionalized membranes resulted in a higher flux recovery ratio (0.694) than the unfunctionalized PES control (0.599). Copper retention was high (>96%) for functionalized membranes. The results indicate that CuO NPs and MPC-SH can reduce organic fouling with only limited copper leaching.
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Affiliation(s)
- Cannon Hackett
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, AR 72701, USA; (C.H.); (M.A.)
| | - Mojtaba Abolhassani
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, AR 72701, USA; (C.H.); (M.A.)
| | - Lauren F. Greenlee
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802, USA;
| | - Audie K. Thompson
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, AR 72701, USA; (C.H.); (M.A.)
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3
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Kékedy‐Nagy L, Abolhassani M, Greenlee LF, Pollet BG. The electrochemistry of ammonium dihydrogen phosphate, disodium phosphate, ammonium chloride on Mg‐based and polycrystalline Pt electrodes. Electrochemical Science Adv 2022. [DOI: 10.1002/elsa.202100067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- László Kékedy‐Nagy
- Ralph E. Martin, Department of Chemical Engineering University of Arkansas Fayetteville Arkansas USA
| | - Mojtaba Abolhassani
- Ralph E. Martin, Department of Chemical Engineering University of Arkansas Fayetteville Arkansas USA
| | - Lauren F. Greenlee
- Ralph E. Martin, Department of Chemical Engineering University of Arkansas Fayetteville Arkansas USA
| | - Bruno G. Pollet
- Department of Energy and Process Engineering, Faculty of Engineering Norwegian University of Science and Technology (NTNU) Trondheim Norway
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Kékedy-Nagy L, English L, Anari Z, Abolhassani M, Pollet BG, Popp J, Greenlee LF. Electrochemical nutrient removal from natural wastewater sources and its impact on water quality. Water Res 2022; 210:118001. [PMID: 34974342 DOI: 10.1016/j.watres.2021.118001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 12/07/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
In this study, a suite of natural wastewater sources is tested to understand the effects of wastewater composition and source on electrochemically driven nitrogen and phosphorus nutrient removal. Kinetics, electrode behavior, and removal efficiency were evaluated during electrochemical precipitation, whereby a sacrificial magnesium (Mg) anode was used to drive precipitation of ammonium and phosphate. The electrochemical reactor demonstrated fast kinetics in the natural wastewater matrices, removing up to 54% of the phosphate present in natural wastewater within 1 min, with an energy input of only 0.04 kWh.m-3. After 1 min, phosphate removal followed a zero-order rate law in the 1 min - 30 min range. The zero-order rate constant (k) appears to depend upon differences in wastewater composition, where a faster rate constant is associated with higher Cl- and NH4+ concentrations, lower Ca2+ concentrations, and higher organic carbon content. The sacrificial Mg anode showed the lowest corrosion resistance in the natural industrial wastewater source, with an increased corrosion rate (vcorr) of 15.8 mm.y-1 compared to 1.9-3.5 mm.y-1 in municipal wastewater sources, while the Tafel slopes (β) showed a direct correlation with the natural wastewater composition and origin. An overall improvement of water quality was observed where important water quality parameters such as total organic carbon (TOC), total suspended solids (TSS), and turbidity showed a significant decrease. An economic analysis revealed costs based upon experimental Mg consumption are estimated to range from 0.19 $.m-3 to 0.30 $.m-3, but costs based upon theoretical Mg consumption range from 0.09 $.m-3 to 0.18 $.m-3. Overall, this study highlights that water chemistry parameters control nutrient recovery, while electrochemical treatment does not directly produce potable water, and that economic analysis should be based upon experimentally-determined Mg consumption data. Synopsis Statement: Magnesium-driven electrochemical precipitation of natural wastewater sources enables fast kinetics for phosphate removal at low energy input.
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Affiliation(s)
- László Kékedy-Nagy
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, 3202 Bell Engineering Center, Fayetteville AR 72701, United States; Department of Electrical and Computer Engineering, Concordia University, Center of Structural and Functional Genomics, 7141 Sherbrooke St. West, Montreal H4B 1R6, Canada
| | - Leah English
- Department of Agricultural Economics and Agribusiness, University of Arkansas, 217 Agriculture Building, Fayetteville, AR 72701, United States
| | - Zahra Anari
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, 3202 Bell Engineering Center, Fayetteville AR 72701, United States; Department of Chemical Engineering, Pennsylvania State University, 121 Chemical and Biomedical Engineering Building, University Park, PA 16802 United States
| | - Mojtaba Abolhassani
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, 3202 Bell Engineering Center, Fayetteville AR 72701, United States
| | - Bruno G Pollet
- Hydrogen Energy and Sonochemistry research group, Department of Energy and Process Engineering, Faculty of Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway; Green Hydrogen Lab, Hydrogen Research Institute, Université du Québec à Trois-Rivières, 3351 Boulevard des Forges, Trois-Rivières, Québec G9A 5H7, Canada
| | - Jennie Popp
- Department of Agricultural Economics and Agribusiness, University of Arkansas, 217 Agriculture Building, Fayetteville, AR 72701, United States
| | - Lauren F Greenlee
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, 3202 Bell Engineering Center, Fayetteville AR 72701, United States; Department of Chemical Engineering, Pennsylvania State University, 121 Chemical and Biomedical Engineering Building, University Park, PA 16802 United States.
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Acharya P, Manso RH, Hoffman AS, Bakovic SIP, Kékedy-Nagy L, Bare SR, Chen J, Greenlee LF. Fe Coordination Environment, Fe-Incorporated Ni(OH)2 Phase, and Metallic Core Are Key Structural Components to Active and Stable Nanoparticle Catalysts for the Oxygen Evolution Reaction. ACS Catal 2022. [DOI: 10.1021/acscatal.1c04881] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Prashant Acharya
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Ryan H. Manso
- Department of Chemistry & Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Adam S. Hoffman
- Stanford Synchrotron Radiation Lightsource, Menlo Park, California 94025, United States
| | - Sergio I. Perez Bakovic
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - László Kékedy-Nagy
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
- Department of Electrical and Computer Engineering, Concordia University, Montreal, Quebec H3G 1M8, Canada
| | - Simon R. Bare
- Stanford Synchrotron Radiation Lightsource, Menlo Park, California 94025, United States
| | - Jingyi Chen
- Department of Chemistry & Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Lauren F. Greenlee
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States
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Vahdatifar S, Ali Khodadadi A, Mortazavi Y, Greenlee LF. Functionalized open-ended vertically aligned carbon nanotube composite membranes with high salt rejection and enhanced slip flow for desalination. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.119773] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Qing G, Foster SL, Anari Z, Matlock M, Thoma G, Greenlee LF. Disinfection/ammonia removal from aquaculture wastewater and disinfection of irrigation water using electrochemical flow cells: A case study in Hawaii. Water Environ Res 2021; 93:2149-2168. [PMID: 34022089 DOI: 10.1002/wer.1588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/20/2021] [Accepted: 05/16/2021] [Indexed: 06/12/2023]
Abstract
This field case study reports findings on disinfection/ammonia removal from aquaculture wastewater and disinfection of irrigation water carried out at an aquaculture farm and two irrigation locations in Hawaii. We used a flow cell incorporating PtRu/graphite anode and graphite cathode for the disinfection/ammonia removal from aquaculture wastewater, and a flow cell assembled with graphite plates as both anode and cathode for the disinfection of irrigation water. The removal of ammonia followed the indirect oxidation mechanism mediated by free chlorine electro-generated at the PtRu/graphite anode. Ammonia removal rate increased with the increase in NaCl concentration, applied current density, or flow rate. The disinfection of aquaculture wastewater can be readily achieved due to the presence of highly germicidal free chlorine species. The disinfection of irrigation water was realized without the addition of chemicals. The disinfection mechanism was attributed to the formation of free chlorine from the anodic oxidation of chloride ions naturally occurring in the water sources. The disinfection efficiency decreased with increasing organic matter concentration. In addition to the flow cell approach, we also successfully demonstrated the disinfection of irrigation water by adding electrolyzed NaCl solution or purging with a mixture of air and chlorine gas, both of which were generated on-site. PRACTITIONER POINTS: Field case study on disinfection/ammonia removal from aquaculture wastewater and disinfection of irrigation water was carried out in Hawaii. Electrochemical flow cell assembled with PtRu/graphite anode and graphite cathode effectively removes ammonia from aquaculture wastewater. Ammonia removal proceeds via the indirect oxidation mechanism mediated by free chlorine electro-generated at the PtRu/graphite anode. Electrochemical flow cell assembled with commercial graphite electrodes enables fast disinfection of coliform bacteria and E. coli. The primary disinfection mechanism is through chlorine species electro-generated from chloride oxidation at the graphite anode.
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Affiliation(s)
- Geletu Qing
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, AR, USA
| | - Shelby L Foster
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, AR, USA
| | - Zahra Anari
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, AR, USA
| | - Marty Matlock
- Department of Biological and Agricultural Engineering, University of Arkansas, Fayetteville, AR, USA
| | - Greg Thoma
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, AR, USA
| | - Lauren F Greenlee
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, AR, USA
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Ostervold L, Perez Bakovic SI, Hestekin J, Greenlee LF. Electrochemical biomass upgrading: degradation of glucose to lactic acid on a copper(ii) electrode. RSC Adv 2021; 11:31208-31218. [PMID: 35496889 PMCID: PMC9041372 DOI: 10.1039/d1ra06737k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 09/15/2021] [Indexed: 12/22/2022] Open
Abstract
Biomass upgrading - the conversion of biomass waste into value-added products - provides a possible solution to reduce global dependency on nonrenewable resources. This study investigates the possibility of green biomass upgrading for lactic acid production by electrochemically-driven degradation of glucose. Herein we report an electrooxidized copper(ii) electrode which exhibits a turnover frequency of 5.04 s-1 for glucose conversion. Chronoamperometry experiments under varied potentials, alkalinity, and electrode preparation achieved a maximum lactic acid yield of 23.3 ± 1.2% and selectivity of 31.1 ± 1.9% (1.46 V vs. RHE, 1.0 M NaOH) for a room temperature and open-to-atmosphere reaction. Comparison between reaction conditions revealed lactic acid yield depends on alkalinity and applied potential, while pre-oxidation of the copper had a negligible effect on yield. Post-reaction cyclic voltammetry studies indicated no loss in reactivity for copper(ii) electrodes after a 30 hour reaction. Finally, a mechanism dependent on solvated Cu2+ species is proposed as evidenced by similar product distributions in electrocatalytic and thermocatalytic systems.
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Affiliation(s)
- Lars Ostervold
- Department of Chemical Engineering, Pennsylvania State University University Park PA USA .,Ralph E. Martin Department of Chemical Engineering Fayetteville AR USA
| | | | - Jamie Hestekin
- Ralph E. Martin Department of Chemical Engineering Fayetteville AR USA
| | - Lauren F Greenlee
- Department of Chemical Engineering, Pennsylvania State University University Park PA USA .,Ralph E. Martin Department of Chemical Engineering Fayetteville AR USA
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Qing G, Anari Z, Foster SL, Matlock M, Thoma G, Greenlee LF. Electrochemical disinfection of irrigation water with a graphite electrode flow cell. Water Environ Res 2021; 93:535-548. [PMID: 32920945 DOI: 10.1002/wer.1456] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 09/04/2020] [Accepted: 09/07/2020] [Indexed: 06/11/2023]
Abstract
In this work, we report experimental studies on the disinfection of irrigation water using a flow cell assembled with low-cost graphite plates as both anode and cathode. Natural irrigation waters collected from two irrigation locations (Reservoir 225 and Bott Well Pond) in Hawaii were used, and synthetic irrigation waters were prepared based on the chemical analysis of natural irrigation waters. The concentration of chloride was 10.2 mg/L in the synthetic Reservoir 225 water and 6.9 mg/L in the synthetic Bott Well pond water. Escherichia coli K12 ER2738 was selected as a model bacterium to evaluate the disinfection capability of the flow cell. Experiments performed in the synthetic irrigation waters showed that E. coli was inactivated by free chlorine species electro-generated from oxidation of chloride ions at the graphite anode. Complete removal of E. coli was achieved within 10 min in the synthetic irrigation waters. The disinfection of the natural irrigation waters took about four times longer than the disinfection of the synthetic irrigation waters. This result is most likely due to the presence of organic matter (and possibly other oxidizable species) in the natural irrigation waters. PRACTITIONER POINTS: Electrochemical flow cell disinfects to 99.9% with commercial graphite electrodes. E. coli is removed in 10 min from synthetic irrigation water by a flow cell. E. coli removal takes 4× longer in natural irrigation water. A minimum current density of ≥1 mA/cm2 is required for disinfection. The primary disinfection mechanism is through chlorine generated from chloride ions.
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Affiliation(s)
- Geletu Qing
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas
| | - Zahra Anari
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas
| | - Shelby L Foster
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas
| | - Marty Matlock
- Department of Biological and Agricultural Engineering, University of Arkansas, Fayetteville, Arkansas
| | - Greg Thoma
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas
| | - Lauren F Greenlee
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas
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Kékedy-Nagy L, Abolhassani M, Greenlee LF, Pollet BG. An Electrochemical Study of Ammonium Dihydrogen Phosphate on Mg and Mg Alloy Electrodes. Electrocatalysis (N Y) 2021. [DOI: 10.1007/s12678-021-00646-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
AbstractIn this work, the electrochemistry of ammonium dihydrogen phosphate in aqueous solution on Mg and Mg AZ31 alloy (Al 3 wt%, Zn 1 wt%, balanced Mg) electrodes was studied using electrochemical characterization similar to electro-agglomeration and physical characterization to shed some light on the electrochemical mechanism of struvite formation as phosphate precipitation in waste. It was found that the Mg AZ31 alloy exhibited higher corrosion current densities (jcorr), and thus higher Mg dissolution rates and corrosion rates (vcorr) when compared with pure Mg. This finding was confirmed by ion chromatography (IC) analysis. Results also showed a phosphorus removal efficiency (PRem) of 16.8% together with ~53 mL H2 production for pure Mg and 17.2% with ~61 mL H2 production for Mg AZ31 alloy. The precipitates formed on the two Mg electrode materials were physically characterized by SEM, XRD, XPS, and energy-dispersive X-ray spectroscopy, which indicated the formation of struvite (magnesium ammonium phosphate hexahydrate-MgNH4PO4*6H2O). It was found that (i) the thickness of the films was influenced by the applied scan rates, which also had a significant impact on the morphology, and (ii) hydrogen bubble formation influenced the precipitates, whereby the film thicknesses were negatively impacted.
Graphical abstract
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11
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Perez Bakovic SI, Acharya P, Watkins M, Thornton H, Hou S, Greenlee LF. Electrochemically active surface area controls HER activity for FexNi100−x films in alkaline electrolyte. J Catal 2021. [DOI: 10.1016/j.jcat.2020.12.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Kékedy-Nagy L, Abolhassani M, Perez Bakovic SI, Anari Z, Moore Ii JP, Pollet BG, Greenlee LF. Electroless Production of Fertilizer (Struvite) and Hydrogen from Synthetic Agricultural Wastewaters. J Am Chem Soc 2020; 142:18844-18858. [PMID: 33084316 DOI: 10.1021/jacs.0c07916] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The drive toward sustainable phosphorus (P) recovery from agricultural and municipal wastewater streams has intensified. However, combining P recovery with energy conservation is perhaps one of the greatest challenges of this century. In this study, we report for the first time the simultaneous electroless production of struvite and dihydrogen from aqueous ammonium dihydrogen phosphate (NH4H2PO4) solutions in contact with either a pure magnesium (Mg) or a Mg alloy as the anode and 316 stainless steel (SS) as the cathode placed in a bench-scale electrochemical reactor. During the electroless process (i.e., in the absence of external electrical power), the open circuit potential (OCP), the formation of struvite on the anode, and the generation of dihydrogen at the cathode were monitored. We found that struvite is formed, and that struvite crystal structure/morphology and precipitate film thickness are affected by the concentration of the HnPO4n-3/NH4+ in solution and the composition of the anode. The pure Mg anode produced a porous 0.6-4.1 μm thick film, while the AZ31 Mg alloy produced a more compact 1.7-9.9 μm thick struvite film. Kinetic analyses revealed that Mg dissolution to Mg2+ followed mostly a zero-order kinetic rate law for both Mg anode materials, and the rate constants (k) depended upon the struvite layer morphology. Fourier-transform infrared spectrometry, X-ray diffraction, and scanning electron microscopy indicated that the synthesized struvite was of high quality. The dihydrogen and Mg2+ in solution were detected by a gas chromatography-thermal conductivity detector and ion chromatography, respectively. Furthermore, we fully demonstrate that the reactor was able to remove ∼73% of the HnPO4n-3 present in a natural poultry wastewater as mainly struvite. This study highlights the feasibility of simultaneously producing struvite and dihydrogen from wastewater effluents with no energy input in a green and sustainable approach.
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Affiliation(s)
- László Kékedy-Nagy
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, 3202 Bell Engineering Center, Fayetteville, Arkansas 72701, United States
| | - Mojtaba Abolhassani
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, 3202 Bell Engineering Center, Fayetteville, Arkansas 72701, United States
| | - Sergio I Perez Bakovic
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, 3202 Bell Engineering Center, Fayetteville, Arkansas 72701, United States
| | - Zahra Anari
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, 3202 Bell Engineering Center, Fayetteville, Arkansas 72701, United States
| | - John P Moore Ii
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, 3202 Bell Engineering Center, Fayetteville, Arkansas 72701, United States
| | - Bruno G Pollet
- Hydrogen Energy and Sonochemistry Research Group, Department of Energy and Process Engineering, Faculty of Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway
| | - Lauren F Greenlee
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, 3202 Bell Engineering Center, Fayetteville, Arkansas 72701, United States
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Acharya P, Nelson ZJ, Benamara M, Manso RH, Bakovic SIP, Abolhassani M, Lee S, Reinhart B, Chen J, Greenlee LF. Chemical Structure of Fe-Ni Nanoparticles for Efficient Oxygen Evolution Reaction Electrocatalysis. ACS Omega 2019; 4:17209-17222. [PMID: 31656894 PMCID: PMC6811848 DOI: 10.1021/acsomega.9b01692] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Accepted: 10/03/2019] [Indexed: 06/10/2023]
Abstract
Bimetallic iron-nickel-based nanocatalysts are perhaps the most active for the oxygen evolution reaction (OER) in alkaline electrolytes. Recent developments in literature have suggested that the ratio of iron and nickel in Fe-Ni thin films plays an essential role in the performance and stability of the catalysts. In this work, the metallic ratio of iron to nickel was tested in alloy bimetallic nanoparticles. Similar to thin films, nanoparticles with iron-nickel atomic compositions where the atomic iron percentage is ≤50% outperformed nanoparticles with iron-nickel ratios of >50%. Nanoparticles of Fe20Ni80, Fe50Ni50, and Fe80Ni20 compositions were evaluated and demonstrated to have overpotentials of 313, 327,, and 364 mV, respectively, at a current density of 10 mA/cm2. While the Fe20Ni80 composition might be considered to have the best OER performance at low current densities, Fe50Ni50 was found to have the best current density performance at higher current densities, making this composition particularly relevant for electrolysis conditions. However, when stability was evaluated through chronoamperometry and chronopotentiometry, the Fe80Ni20 composition resulted in the lowest degradation rates of 2.9 μA/h and 17.2 μV/h, respectively. These results suggest that nanoparticles with higher iron and lower nickel content, such as the Fe80Ni20 composition, should be still taken into consideration while optimizing these bimetallic OER catalysts for overall electrocatalytic performance. Characterization by electron microscopy, diffraction, and X-ray spectroscopy provides detailed chemical and structural information on as-synthesized nanoparticle materials.
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Affiliation(s)
- Prashant Acharya
- Ralph
E. Martin Department of Chemical Engineering, Institute for Nanoscience and Engineering, and Department of
Chemistry and Biochemistry, University of
Arkansas, Fayetteville, Arkansas 72701, United
States
| | - Zachary J. Nelson
- Ralph
E. Martin Department of Chemical Engineering, Institute for Nanoscience and Engineering, and Department of
Chemistry and Biochemistry, University of
Arkansas, Fayetteville, Arkansas 72701, United
States
| | - Mourad Benamara
- Ralph
E. Martin Department of Chemical Engineering, Institute for Nanoscience and Engineering, and Department of
Chemistry and Biochemistry, University of
Arkansas, Fayetteville, Arkansas 72701, United
States
| | - Ryan H. Manso
- Ralph
E. Martin Department of Chemical Engineering, Institute for Nanoscience and Engineering, and Department of
Chemistry and Biochemistry, University of
Arkansas, Fayetteville, Arkansas 72701, United
States
| | - Sergio I. Perez Bakovic
- Ralph
E. Martin Department of Chemical Engineering, Institute for Nanoscience and Engineering, and Department of
Chemistry and Biochemistry, University of
Arkansas, Fayetteville, Arkansas 72701, United
States
| | - Mojtaba Abolhassani
- Ralph
E. Martin Department of Chemical Engineering, Institute for Nanoscience and Engineering, and Department of
Chemistry and Biochemistry, University of
Arkansas, Fayetteville, Arkansas 72701, United
States
| | - Sungsik Lee
- Advanced
Photon Source, Argonne National Lab, Argonne, Illinois 60439, United States
| | - Benjamin Reinhart
- Advanced
Photon Source, Argonne National Lab, Argonne, Illinois 60439, United States
| | - Jingyi Chen
- Ralph
E. Martin Department of Chemical Engineering, Institute for Nanoscience and Engineering, and Department of
Chemistry and Biochemistry, University of
Arkansas, Fayetteville, Arkansas 72701, United
States
| | - Lauren F. Greenlee
- Ralph
E. Martin Department of Chemical Engineering, Institute for Nanoscience and Engineering, and Department of
Chemistry and Biochemistry, University of
Arkansas, Fayetteville, Arkansas 72701, United
States
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14
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Loney CN, Perez Bakovic SI, Xu C, Graybill A, Greenlee LF, Renner JN. Interactions of Polyproline II Helix Peptides with Iron(III) Oxide. ChemistrySelect 2019. [DOI: 10.1002/slct.201901817] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Charles N. Loney
- Department of Chemical and Biomolecular EngineeringCase Western Reserve University 10900 Euclid Ave. Cleveland, OH 44106
| | - Sergio I. Perez Bakovic
- Ralph E. Martin Department of Chemical EngineeringUniversity of Arkansas 4183 Bell Engineering Center Fayetteville, AR 72701
| | - Cheyan Xu
- Department of Chemical and Biomolecular EngineeringCase Western Reserve University 10900 Euclid Ave. Cleveland, OH 44106
| | - Ashley Graybill
- Department of Chemical and Biomolecular EngineeringCase Western Reserve University 10900 Euclid Ave. Cleveland, OH 44106
| | - Lauren F. Greenlee
- Ralph E. Martin Department of Chemical EngineeringUniversity of Arkansas 4183 Bell Engineering Center Fayetteville, AR 72701
| | - Julie N. Renner
- Department of Chemical and Biomolecular EngineeringCase Western Reserve University 10900 Euclid Ave. Cleveland, OH 44106
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15
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Manso RH, Acharya P, Deng S, Crane CC, Reinhart B, Lee S, Tong X, Nykypanchuk D, Zhu J, Zhu Y, Greenlee LF, Chen J. Controlling the 3-D morphology of Ni-Fe-based nanocatalysts for the oxygen evolution reaction. Nanoscale 2019; 11:8170-8184. [PMID: 30775739 DOI: 10.1039/c8nr10138h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Controlling the 3-D morphology of nanocatalysts is one of the underexplored but important approaches for improving the sluggish kinetics of the oxygen evolution reaction (OER) in water electrolysis. This work reports a scalable, oil-based method based on thermal decomposition of organometallic complexes to yield highly uniform Ni-Fe-based nanocatalysts with a well-defined morphology (i.e. Ni-Fe core-shell, Ni/Fe alloy, and Fe-Ni core-shell). Transmission electron microscopy reveals their morphology and composition to be NiOx-FeOx/NiOx core-mixed shell, NiOx/FeOx alloy, and FeOx-NiOx core-shell. X-ray techniques resolve the electronic structures of the bulk and are supported by electron energy loss spectroscopy analysis of individual nanoparticles. These results suggest that the crystal structure of Ni is most likely to contain α-Ni(OH)2 and that the chemical environment of Fe is variable, depending on the morphology of the nanoparticle. The Ni diffusion from the amorphous Ni-based core to the iron oxide shell makes the NiOx-NiOx/FeOx core-mixed shell structure the most active and the most stable nanocatalyst, which outperforms the comparison NiOx/FeOx alloy nanoparticles expected to be active for the OER. This study suggests that the chemical environment of the mixed NiOx/FeOx alloy composition is important to achieve high electrocatalytic activity for the OER and that the 3-D morphology plays a key role in the optimization of the electrocatalytic activity and stability of the nanocatalyst for the OER.
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Affiliation(s)
- Ryan H Manso
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
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16
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Esfahani MR, Aktij SA, Dabaghian Z, Firouzjaei MD, Rahimpour A, Eke J, Escobar IC, Abolhassani M, Greenlee LF, Esfahani AR, Sadmani A, Koutahzadeh N. Nanocomposite membranes for water separation and purification: Fabrication, modification, and applications. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2018.12.050] [Citation(s) in RCA: 237] [Impact Index Per Article: 47.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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17
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Greenlee LF, Renner JN, Foster SL. The Use of Controls for Consistent and Accurate Measurements of Electrocatalytic Ammonia Synthesis from Dinitrogen. ACS Catal 2018. [DOI: 10.1021/acscatal.8b02120] [Citation(s) in RCA: 192] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lauren F. Greenlee
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, 3202 Bell Engineering Center, Fayetteville, Arkansas 72701, United States
| | - Julie N. Renner
- Department of Chemical and Biomolecular Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Shelby L. Foster
- Ralph E. Martin Department of Chemical Engineering, University of Arkansas, 3202 Bell Engineering Center, Fayetteville, Arkansas 72701, United States
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18
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Foster SL, Bakovic SIP, Duda RD, Maheshwari S, Milton RD, Minteer SD, Janik MJ, Renner JN, Greenlee LF. Catalysts for nitrogen reduction to ammonia. Nat Catal 2018. [DOI: 10.1038/s41929-018-0092-7] [Citation(s) in RCA: 676] [Impact Index Per Article: 112.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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19
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Abolhassani M, Griggs CS, Gurtowski LA, Mattei-Sosa JA, Nevins M, Medina VF, Morgan TA, Greenlee LF. Scalable Chitosan-Graphene Oxide Membranes: The Effect of GO Size on Properties and Cross-Flow Filtration Performance. ACS Omega 2017; 2:8751-8759. [PMID: 31457405 PMCID: PMC6645527 DOI: 10.1021/acsomega.7b01266] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/22/2017] [Indexed: 05/12/2023]
Abstract
Chitosan (CS)-graphene oxide (GO) composite films were fabricated, characterized, and evaluated as pressure-driven water filtration membranes. GO particles were incorporated into a chitosan polymer solution to form a suspension that was cast as a membrane via evaporative phase inversion allowing for scale-up for cross-flow testing conditions. Morphology and composition results for nano and granular GO in the CS matrix indicate that the particle size of GO impacts the internal membrane morphology as well as the structural order and the chemical composition. Performance of the membranes was evaluated with cationic and anionic organic probe molecules and revealed charge-dependent mechanisms of dye removal. The CSGO membranes had rejections of at least 95% for cationic methylene blue with mass balances obtained from measurements of the feed, concentrate, and permeate. This result suggests the dominant mechanism of removal is physical rejection for both GO particle sizes. For anionic methyl orange, the results indicate sorption as the dominant mechanism of removal, and performance is dependent on both GO particle size and time, with micrometer-scale GO removing 68-99% and nanometer-scale GO showing modest removal of 29-64%. The pure water flux for CSGO composite membranes ranged from 2-4.5 L/m2 h at a transmembrane pressure of 344 kPa (3.44 bar), with pure water permeance ranging from 5.8 × 10-3 to 0.01 L/m2 h kPa (0.58-1.3 L/m2 h bar). Based on the 41 μm membrane thickness obtained from microscopy, the hydraulic permeability ranged from 0.24-0.54 L μm/m2 h kPa (24.4-54.1 L μm/m2 h bar).
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Affiliation(s)
- Mojtaba Abolhassani
- Ralph
E. Martin Department of Chemical Engineering, 3202 Bell Engineering
Center, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Chris S. Griggs
- U.S.
Army Engineer Research Development Center, 3909 Halls Ferry Road, Vicksburg, Mississippi 39180, United States
| | - Luke A. Gurtowski
- U.S.
Army Engineer Research Development Center, 3909 Halls Ferry Road, Vicksburg, Mississippi 39180, United States
| | - Jose A. Mattei-Sosa
- U.S.
Army Engineer Research Development Center, 3909 Halls Ferry Road, Vicksburg, Mississippi 39180, United States
| | - Michelle Nevins
- U.S.
Army Engineer Research Development Center, 3909 Halls Ferry Road, Vicksburg, Mississippi 39180, United States
- State
University of New York at Stony Brook, Stony Brook, New York 11794, United States
| | - Victor F. Medina
- U.S.
Army Engineer Research Development Center, 3909 Halls Ferry Road, Vicksburg, Mississippi 39180, United States
| | - Timothy A. Morgan
- Institute
for Nanoscience and Engineering, University
of Arkansas, 731 W Dickson
Street, Fayetteville, Arkansas 72701, United States
| | - Lauren F. Greenlee
- Ralph
E. Martin Department of Chemical Engineering, 3202 Bell Engineering
Center, University of Arkansas, Fayetteville, Arkansas 72701, United States
- E-mail: . Phone: 4987-575-5976. Fax: 479-575-7926
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20
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Abstract
Zero-valent iron (ZVI) nanoparticles are susceptible to oxidation and are therefore sensitive to postsynthesis processing, including both separation and storage techniques. Two separation methods, centrifugation and magnetic separation, were evaluated in this study. Nanoparticle stability during storage in ethanol-water solutions was also studied, and the influence of both water and aeration on nanoparticle oxidation was determined. Nanoparticle morphology and extent of oxidation were analyzed with electron microscopy, elemental analysis, zeta potential, and X-ray photoelectron spectroscopy. Microscopy results suggest that the separation method used affects the extent of stabilizer that remains adsorbed to the nanoparticles, but both separation methods result in minimal oxidation of the nanoparticles. However, the addition of aerated water to nanoparticle-ethanol storage solutions caused nanoparticle oxidation; an increase in the volume fraction of water added caused a linear increase in oxygen content based on elemental analysis of nanoparticle samples. X-ray photoelectron spectroscopy results suggest that organic stabilizer is incorporated into the nanoparticle structure as oxidation occurs.
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21
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Candelaria SL, Bedford NM, Woehl TJ, Rentz NS, Showalter AR, Pylypenko S, Bunker BA, Lee S, Reinhart B, Ren Y, Ertem SP, Coughlin EB, Sather NA, Horan JL, Herring AM, Greenlee LF. Multi-Component Fe–Ni Hydroxide Nanocatalyst for Oxygen Evolution and Methanol Oxidation Reactions under Alkaline Conditions. ACS Catal 2016. [DOI: 10.1021/acscatal.6b02552] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Stephanie L. Candelaria
- Applied
Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, Colorado 80305, United States
| | - Nicholas M. Bedford
- Applied
Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, Colorado 80305, United States
| | - Taylor J. Woehl
- Applied
Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, Colorado 80305, United States
| | - Nikki S. Rentz
- Applied
Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, Colorado 80305, United States
| | - Allison R. Showalter
- Department
of Physics, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Svitlana Pylypenko
- Department
of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Bruce A. Bunker
- Department
of Physics, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Sungsik Lee
- X-Ray
Sciences Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Benjamin Reinhart
- X-Ray
Sciences Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Yang Ren
- X-Ray
Sciences Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - S. Piril Ertem
- Department
of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - E. Bryan Coughlin
- Department
of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Nicholas A. Sather
- Department
of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - James L. Horan
- Department
of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Andrew M. Herring
- Department
of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Lauren F. Greenlee
- Applied
Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, Colorado 80305, United States
- Ralph
E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
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22
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Torrey JD, Kirschling TL, Greenlee LF. Processing and Characterization of Nanoparticle Coatings for Quartz Crystal Microbalance Measurements. J Res Natl Inst Stand Technol 2015; 120:1-10. [PMID: 26958434 PMCID: PMC4730678 DOI: 10.6028/jres.120.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 01/21/2015] [Indexed: 06/05/2023]
Abstract
The quartz-crystal microbalance is a sensitive and versatile tool for measuring adsorption of a variety of compounds (e.g. small molecules, polymers, biomolecules, nanoparticles and cells) to surfaces. While the technique has traditionally been used for measuring adsorption to flat surfaces and thin ridged films, it can also be extended to study adsorption to nanoparticle surfaces when the nanoparticles are fixed to the crystal surface. The sensitivity and accuracy of the measurement depend on the users' ability to reproducibly prepare a thin uniform nanoparticle coating. This study evaluated four coating techniques, including spin coating, spray coating, drop casting, and electrophoretic deposition, for two unique particle chemistries [nanoscale zero valent iron (nZVI) and titanium dioxide (TiO2)] to produce uniform and reproducible nanoparticle coatings for real-time quartz-crystal microbalance measurements. Uniform TiO2 coatings were produced from a 50 mg/mL methanol suspension via spin coating. Nanoscale zero-valent iron was best applied by spray coating a low concentration 1.0 mg/mL suspended in methanol. The application of multiple coatings, rather than an increase in the suspension concentration, was the best method to increase the mass of nanoparticles on the crystal surface while maintaining coating uniformity. An upper mass threshold was determined to be approximately 96 µg/cm(2); above this mass, coatings no longer maintained their uniform rigid characteristic, and a low signal to noise ratio resulted in loss of measurable signal from crystal resonances above the fundamental.
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Affiliation(s)
- Jessica D. Torrey
- Technical Service Center of the US Bureau of Reclamation, Lakewood, CO, 80225
- National Institute of Standards and Technology, Boulder, CO, 80305
| | - Teresa L. Kirschling
- National Institute of Standards and Technology, Boulder, CO, 80305
- United States Geological Survey, Lakewood, CO, 80225
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23
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Abstract
Zero valent iron (ZVI) nanoparticles are versatile in their ability to remove a wide variety of water contaminants, and ZVI-based bimetallic nanoparticles show increased reactivity above that of ZVI alone. ZVI nanoparticles degrade contaminants through the reactive species (e.g., OH*, H(2(g)), H(2)O(2)) that are produced during iron oxidation. Measurement and modeling of aqueous ZVI nanoparticle oxidation kinetics are therefore necessary to optimize nanoparticle design. Stabilized ZVI and iron-nickel nanoparticles of approximately 150 nm in diameter were synthesized through solution chemistry, and nanoparticle oxidation kinetics were determined via measured mass change using a quartz crystal microbalance (QCM). Under flowing aerated water, ZVI nanoparticles had an initial exponential growth behavior indicating surface-dominated oxidation controlled by migration of species (H(2)O and O(2)) to the surface. A region of logarithmic growth followed the exponential growth which, based on the Mott-Cabrera model of thin oxide film growth, suggests a reaction dominated by movement of species (e.g., iron cations and oxygen anions) through the oxide layer. The presence of ethanol or a nickel shell on the ZVI nanoparticles delayed the onset of iron oxidation and reduced the extent of oxidation. In oxygenated water, ZVI nanoparticles oxidized primarily to the iron oxide-hydroxide lepidocrocite.
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Affiliation(s)
- Lauren F Greenlee
- Applied Chemicals and Materials Division National Institute of Standards and Technology 325 Broadway, Boulder, Colorado 80305, USA.
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24
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Greenlee LF, Testa F, Lawler DF, Freeman BD, Moulin P. The effect of antiscalant addition on calcium carbonate precipitation for a simplified synthetic brackish water reverse osmosis concentrate. Water Res 2010; 44:2957-2969. [PMID: 20350741 DOI: 10.1016/j.watres.2010.02.024] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 02/15/2010] [Accepted: 02/15/2010] [Indexed: 05/29/2023]
Abstract
The primary limitations to inland brackish water reverse osmosis (RO) desalination are the cost and technical feasibility of concentrate disposal. To decrease concentrate volume, a side-stream process can be used to precipitate problematic scaling salts and remove the precipitate with a solid/liquid separation step. The treated concentrate can then be purified through a secondary reverse osmosis stage to increase overall recovery and decrease the volume of waste requiring disposal. Antiscalants are used in an RO system to prevent salt precipitation but might affect side-stream concentrate treatment. Precipitation experiments were performed on a synthetic RO concentrate with and without antiscalant; of particular interest was the precipitation of calcium carbonate. Particle size distributions, calcium precipitation, microfiltration flux, and scanning electron microscopy were used to evaluate the effects of antiscalant type, antiscalant concentration, and precipitation pH on calcium carbonate precipitation and filtration. Results show that antiscalants can decrease precipitate particle size and change the shape of the particles; smaller particles can cause an increase in microfiltration flux decline during the solid/liquid separation step. The presence of antiscalant during precipitation can also decrease the mass of precipitated calcium carbonate.
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Affiliation(s)
- Lauren F Greenlee
- The University of Texas at Austin, Department of Chemical Engineering, 1 University Station, Austin, TX 78712, USA
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25
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Greenlee LF, Testa F, Lawler DF, Freeman BD, Moulin P. Effect of antiscalants on precipitation of an RO concentrate: metals precipitated and particle characteristics for several water compositions. Water Res 2010; 44:2672-2684. [PMID: 20172582 DOI: 10.1016/j.watres.2010.01.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2009] [Revised: 01/22/2010] [Accepted: 01/26/2010] [Indexed: 05/28/2023]
Abstract
Inland brackish water reverse osmosis (RO) is economically and technically limited by the large volume of salty waste (concentrate) produced. The use of a controlled precipitation step, followed by solid/liquid separation (filtration), has emerged as a promising side-stream treatment process to treat reverse osmosis concentrate and increase overall system recovery. The addition of antiscalants to the RO feed prevents precipitation within the membrane system but might have a deleterious effect on a concentrate treatment process that uses precipitation to remove problematic precipitates. The effects of antiscalant type and concentration on salt precipitation and precipitate particle morphology were evaluated for several water compositions. The primary precipitate for the synthetic brackish waters tested was calcium carbonate; the presence of magnesium, sulfate, minor ions, and antiscalant compounds affected the amount of calcium precipitated, as well as the phases of calcium carbonate formed during precipitation. Addition of antiscalant decreased calcium precipitation but increased incorporation of magnesium and sulfate into precipitating calcium carbonate. Antiscalants prevented the growth of nucleated precipitates, resulting in the formation of small (100-200 nm diameter) particles, as well as larger (6-10 microm) particles. Elemental analysis revealed changes in composition and calcium carbonate polymorph with antiscalant addition and antiscalant type. Results indicate that the presence of antiscalants does reduce the extent of calcium precipitation and can worsen subsequent filtration performance.
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Affiliation(s)
- Lauren F Greenlee
- The University of Texas at Austin, Department of Chemical Engineering, 1 University Station C0400 Austin, TX 78712, USA
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26
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Greenlee LF, Lawler DF, Freeman BD, Marrot B, Moulin P. Reverse osmosis desalination: water sources, technology, and today's challenges. Water Res 2009; 43:2317-2348. [PMID: 19371922 DOI: 10.1016/j.watres.2009.03.010] [Citation(s) in RCA: 1032] [Impact Index Per Article: 68.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Revised: 03/02/2009] [Accepted: 03/06/2009] [Indexed: 05/26/2023]
Abstract
Reverse osmosis membrane technology has developed over the past 40 years to a 44% share in world desalting production capacity, and an 80% share in the total number of desalination plants installed worldwide. The use of membrane desalination has increased as materials have improved and costs have decreased. Today, reverse osmosis membranes are the leading technology for new desalination installations, and they are applied to a variety of salt water resources using tailored pretreatment and membrane system design. Two distinct branches of reverse osmosis desalination have emerged: seawater reverse osmosis and brackish water reverse osmosis. Differences between the two water sources, including foulants, salinity, waste brine (concentrate) disposal options, and plant location, have created significant differences in process development, implementation, and key technical problems. Pretreatment options are similar for both types of reverse osmosis and depend on the specific components of the water source. Both brackish water and seawater reverse osmosis (RO) will continue to be used worldwide; new technology in energy recovery and renewable energy, as well as innovative plant design, will allow greater use of desalination for inland and rural communities, while providing more affordable water for large coastal cities. A wide variety of research and general information on RO desalination is available; however, a direct comparison of seawater and brackish water RO systems is necessary to highlight similarities and differences in process development. This article brings to light key parameters of an RO process and process modifications due to feed water characteristics.
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Affiliation(s)
- Lauren F Greenlee
- The University of Texas at Austin, Center for Energy and Environmental Resources, Austin, TX 78758, USA.
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