Startseite Natural silica sand modified by calcium oxide as a new adsorbent for uranyl ions removal from aqueous solutions
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Natural silica sand modified by calcium oxide as a new adsorbent for uranyl ions removal from aqueous solutions

  • O. A. Elhefnawy EMAIL logo und A. A. Elabd
Veröffentlicht/Copyright: 28. April 2017
Radiochimica Acta
Aus der Zeitschrift Radiochimica Acta Band 105 Heft 10

Abstract

Calcium oxide modified El-Zafarana silica sand (CMZS) was prepared as a new adsorbent for U(VI) removal from aqueous solutions in a series of batch experiments. The new adsorbent CMZS was characterized by different analysis techniques SEM, EDX, XRD, and FTIR. The influence of many parameters on the removal process like; effect of pH, contact time, U(VI) initial concentration and temperature on U(VI) removal were investigated. Kinetic experiments showed that U(VI) removal on CMZS followed pseudo-second-order kinetics model appropriately and the equilibrium data agreed well with the Langmuir isotherm model. Kinetics and isothermal data reveal the chemisorption process of U(VI) on CMZS. The thermodynamic parameters (ΔH°, ΔS°, ΔG°) were evaluated from temperature dependent adsorption data and the U(VI) removal on CMZS was found to be endothermic and spontaneous in nature. U(VI) desorption from CMZS was studied by a simple acid treatment. The results indicate that CMZS is an effective adsorbent for U(VI) from aqueous solutions.

Keywords: El-Zafarana silica sand; batch technique; calcium oxide; isotherm; kinetics; thermodynamic

References

1. Cao, Q., Liu, Y., Wang, C., Cheng, J.: Phosphorus-modified poly(styrene-co-divinyl benzene)–PAMAM chelating resin for the adsorption of uranium (VI) in aqueous. J. Hazard. Mater. 263, 311 (2013).10.1016/j.jhazmat.2013.05.039Suche in Google Scholar

2. Zhao, Y., Liu, C. X., Feng, M., Chen, Z., Li, S., Tian, G., Wang, L., Huang, J., Li, S.: Solid phase extraction of uranium(VI) onto benzoy lthiourea-anchored activated carbon. J. Hazard. Mater. 176, 119 (2010).10.1016/j.jhazmat.2009.11.005Suche in Google Scholar

3. Elabd, A. A., Zidan, W. I., Abo-aly, M. M., Bakier, E., Attia, M. S.: Uranyl ions adsorption by novel metal hydroxides loaded AmberliteIR120. J. Environ. Radioact. 134, 99 (2014).10.1016/j.jenvrad.2014.02.008Suche in Google Scholar PubMed

4. Duff, M. C., Coughlin, J. U., Hunter, D.B.: Uranium co-precipitation with iron oxideminerals. Geochim. Cosmochim. Acta. 66, 3533 (2002).10.1016/S0016-7037(02)00953-5Suche in Google Scholar

5. Kryvoruchko, A. P., Yurlova, L. Y., Atamanenko, I. D., Kornilovich, B. Y.: Ultrafiltration removal of U(VI) from contaminated water. Desalination. 162, 229 (2004).10.1016/S0011-9164(04)00046-3Suche in Google Scholar

6. Sadeghi, S., Sheikhzadeh, E.: Solid phase extraction using silica gel modified with murexide for preconcentration of uranium (VI) ions from water samples. J. Hazard. Mater. 163, 861 (2009).10.1016/j.jhazmat.2008.07.053Suche in Google Scholar PubMed

7. Hosseini, M. S., Hosseini-Bandegharaei, A.: Comparison of sorption behavior of Th(IV) and U(VI) on modified impregnated resin containing quinizarin with that conventional prepared impregnated resin. J. Hazard. Mater. 190, 755 (2011).10.1016/j.jhazmat.2011.03.111Suche in Google Scholar

8. Majdan, M., Pikus, S., Gajowiak, A., Sternik, D.: Uranium sorption on bentonite modified by octadecyl trimethyl ammonium bromide. J. Hazard. Mater. 184, 662 (2010).10.1016/j.jhazmat.2010.08.089Suche in Google Scholar

9. Graf, W. L., Clark, S. L., Kammerer, M. T., Lehman, T., Randall, K., Schroeder, R.: Geomorphology of heavy metals in the sediments of Queen Creek, Arizona, USA. Catena. 18, 567 (1991).10.1016/0341-8162(91)90039-ZSuche in Google Scholar

10. Payne, T. E., Davis, J. A., Lumpkin, G. R., Chisari, R., Waite, T. D.: Surface complexation model of uranyl sorption on Georgia kaolinite. Appl. Clay Sci. 26, 151 (2004).10.1016/j.clay.2003.08.013Suche in Google Scholar

11. Catalano, J. G., Brown, G. E.: Uranyl adsorption onto montmorillonite: evaluation of binding sites and carbonate complexation. Geochim. Cosmo. Chim. Acta. 69, 2995 (2005).10.1016/j.gca.2005.01.025Suche in Google Scholar

12. Mibus, J., Sachs, S., Pfingsten, W., Nebelung, C., Bernhard, G.: Migration of uranium (IV)/(VI) in the presence of humic acids in quartz sand: a laboratory column study. J. Contam. Hydrol. 89, 199 (2007).10.1016/j.jconhyd.2006.08.005Suche in Google Scholar PubMed

13. Bachmaf, S., Planer-Friedrich, B., Merkel, B. J.: Effect of sulfate, carbonate, and phosphate on the uranium(VI) sorption behavior onto bentonite. Radiochim. Acta. 96, 359 (2008).10.1524/ract.2008.1496Suche in Google Scholar

14. Guerra, D. L., Leidens, V. L., Viana, R. R., Airoldi, C.: Amazon kaolinite functionalized with diethylenetriamine moieties for U(VI) removal: thermodynamic of cationbasic interactions. J. Hazard. Mater. 180, 683 (2010).10.1016/j.jhazmat.2010.04.092Suche in Google Scholar PubMed

15. Pabloa, L. D., Chávez, M. L., Abatal, M.: Adsorption of heavy metals in acid to alkaline environments by montmorillonite and Ca-montmorillonite. Chem. Eng. J. 171, 1276 (2011).10.1016/j.cej.2011.05.055Suche in Google Scholar

16. Elhefnawy, O. A., Zidan, W. I., Abo-Aly, M. M., Bakier, E. M., Elsayed, G. A.: Synthesis of a new Amberlite 7HP sorbent impregnated by Nano manganese dioxide and its applications for uranium separation. Spectrosc. Lett. 47, 131 (2013).10.1080/00387010.2013.773519Suche in Google Scholar

17. Elhefnawy, O. A., Zidan, W. I., Abo-Aly, M. M., Bakier, E. M., Elsayed, G. A.: Synthesis and characterization of a new surface modified Amberlite-7HP resin by nano-iron oxide (Fe3O4) and its application for uranyl ions separation. J. Radioanal. Nucl. Chem. 299, 1821 (2014).10.1007/s10967-013-2879-ySuche in Google Scholar

18. Elhefnawy, O. A., Elabd, A. A.: Enhancing the sorption efficiency of polystyrene by immobilizing MgO and its application for uranium (VI) removal from aqueous solutions. Radiochim. Acta 104, 791 (2016).10.1515/ract-2016-2587Suche in Google Scholar

19. El-Bayaa, A. A., Badawy, N. A., Gamal, A. M., Zidan, I. H., Mowafy, A. R.: Purification of wet process phosphoric acid by decreasing iron and uranium using white silica sand. J. Hazard. Mater. 190, 324 (2011).10.1016/j.jhazmat.2011.03.037Suche in Google Scholar PubMed

20. Awan, M. A., Qazi, I. A., Khalid, I.: Removal of heavy metals through adsorption using sand. China. J. Env. Sci. 15, 413 (2003).Suche in Google Scholar

21. Unob, F., Wongsiri, B., Phaeon, N., Puanngam, M., Shiowatana, J.: Reuse of waste silica as adsorbent for metal removal by iron oxide modification. J. Hazard. Mater. 142, 455 (2007).10.1016/j.jhazmat.2006.08.049Suche in Google Scholar PubMed

22. Gaber, M. A.: Evaluation of some natural ores from Egyptian eastern desert to be utilized in producing of paint materials. J. Pet. Gas Explor. Res. 2, 17 (2012).Suche in Google Scholar

23. Lee, C., Yang, W., Hsieh, C.: Removal of copper (II) by manganese-coated sand in a liquid fluidized-bed reactor. J. Hazard. Mater. 114, 45 (2004).10.1016/j.jhazmat.2004.06.033Suche in Google Scholar

24. Lee, S. M., Laldawngliana, C., Tiwari, D.: Iron oxide nano-particles-immobilized-sand material in the treatment of Cu(II), Cd(II) and Pb(II) contaminated waste waters. Chem. Eng. J. 195, 103 (2012).10.1016/j.cej.2012.04.075Suche in Google Scholar

25. Yadav, S., Srivastava, V., Banerjee, S., Weng, C. H., Sharma, Y. C.: Adsorption characteristics of modified sand for the removal of hexavalent chromium ions from aqueous solutions: kinetic, thermodynamic and equilibrium studies. Catena. 100, 120 (2012).10.1016/j.catena.2012.08.002Suche in Google Scholar

26. Sun, P., Shijirbaatar, A., Fang, J., Owens, G., Lin, D., Zhang, K.: Distinguishable transport behavior of zinc oxide nanoparticles in silica sand and soil columns. Sci. Total Environ. 505, 189 (2015).10.1016/j.scitotenv.2014.09.095Suche in Google Scholar

27. Crawford, S. E., Liber, K.: Effects of clay minerals and organic matter in formulated sediments on the bioavailability of sediment-associated uranium to the freshwater midge, Chironomus dilutes. Sci. Total Environ. 532, 821 (2015).10.1016/j.scitotenv.2015.05.116Suche in Google Scholar

28. Sen, S., Youngman, R. E.: NMR study of Q-speciation and connectivity in K2O–SiO2 glasses with high silica content. J. Non-Cryst. Solids. 331, 100 (2003).10.1016/j.jnoncrysol.2003.08.071Suche in Google Scholar

29. Wacławska, I., Szumera, M.: Influence of MgO (CaO) on the structure of silicate-phosphate glasses. J. Therm. Anal. Calorim. 84, 185 (2006).10.1007/s10973-005-7183-9Suche in Google Scholar

30. Aguiar, H., Serra, J., González, P., León, B.: Structural study of sol-gel silicate glasses by IR and Raman spectroscopies. J. Non-Cryst. Solids. 355, 475 (2009).10.1016/j.jnoncrysol.2009.01.010Suche in Google Scholar

31. Han, Y. S., Demond, A. H., Hayes, K. F.: Impact of dissolved silica on arsenite removal by nano-particulate FeS and FeS-coated sand. Chemosphere 92, 477 (2013).10.1016/j.chemosphere.2013.02.033Suche in Google Scholar PubMed

32. Kuani, W., Shang, L. M., Ming, K., Lin, C.: Removal of Se(IV) and Se(VI) from water by aluminium oxide coated sand. Wat. Res. 32, 915 (1998).10.1016/S0043-1354(97)00228-5Suche in Google Scholar

33. Huet, P. Y., Hsieh, Y. H., Chen, J. C., Chang, C. Y.: Characteristics of manganese-coated sand using SEM and EDAX analysis. J. Colloid Interf. Sci. 272, 308 (2004).10.1016/j.jcis.2003.12.058Suche in Google Scholar PubMed

34. Xuefei, L., Guangxia, Q., Yinglong, S., Hui, X., Wang, Y.: Removal of uranium and gross radioactivity from coal bottom ash by CaCl2 roasting followed by HNO3 leaching. J. Hazard. Mater. 276, 346 (2014).10.1016/j.jhazmat.2014.05.052Suche in Google Scholar PubMed

35. Hana, R. P., Wang, Y. F., Hana, P., Shi, J., Yang, J., Lub, Y. S.: Removal of methylene blue from aqueous solution by chaff in batch mode. J. Hazard. Mater. 137, 550 (2006).10.1016/j.jhazmat.2006.02.029Suche in Google Scholar PubMed

36. Nassar, N. N.: Rapid removal and recovery of Pb(II) from wastewater by magnetic nanoadsorbents. J. Hazard. Mater. 184, 538 (2010).10.1016/j.jhazmat.2010.08.069Suche in Google Scholar PubMed

37. Bakovic, S., Potgieter, H., Waal, D., Popovic, L.: Replacing limestone and linseed oil in the synthesis of putty. J. Appl. Sci. 6, 1009 (2006).10.3923/jas.2006.1009.1016Suche in Google Scholar

38. Sdiri, A., Higashi, T., Bouaziz, S., Benzin, M.: Synthesis and characterization of silica gel from siliceous sands of southern Tunisia. Arab. J. Chem. 7, 486 (2014).10.1016/j.arabjc.2010.11.007Suche in Google Scholar

39. Viriya-empikul, N., Krasae, P., Puttasawat, B., Yoosuk, B., Chollacoop, N., Faungnawakij, K.: Waste shells of mollusk and egg as biodiesel production catalysts. Bioresource Technol. 101, 3765 (2010).10.1016/j.biortech.2009.12.079Suche in Google Scholar PubMed

40. Lesbani, A., Tamba, P., Mohadi, R., Fahmariyanti, A.: Preparation of calcium oxide from achatinafulica as catalyst for production of Biodiesel from cooking oil. Indo. J. Chem. 13, 176 (2013).10.22146/ijc.21302Suche in Google Scholar

41. Serris, E., Favergeon, L., Pijolat, M., Soustelle, M., Nortier, P., Gärtner, R.S., Chopin, T., and Habib, Z.: Study of the hydration of CaO powder by gas-solid reaction. Cem. Concr. Res. 41, 1078 (2011).10.1016/j.cemconres.2011.06.014Suche in Google Scholar

42. Shoval, S., Yariv, S., Michaelian, K., Lapides, I., Bou-deuille, M., Panczer, G.: A fifth OH-stretching band in IR spectra of kaolinites. J. Colloid Interface Sci. 212, 523 (1999).10.1006/jcis.1998.6055Suche in Google Scholar PubMed

43. Frost, R. L., Mendelovici, E.: Modification of fibrous silicates surfaces with organic derivatives: an infrared spectroscopic study. J. Colloid Interface Sci. 294, 47 (2006).10.1016/j.jcis.2005.07.014Suche in Google Scholar PubMed

44. Kalinkin, A. M., Kalinkina, E. V., Zalkind, O. A., Makarova, T. I.: Chemical interaction of calcium oxide and calcium hydroxide with CO2 during mechanical activation. Inorg. Mater. 41, 1073 (2005).10.1007/s10789-005-0263-1Suche in Google Scholar

45. Spence, A., Kelleher, B. P.: FT-IR spectroscopic analysis of kaolinite–microbial interactions. Vib. Spectrosc. 61, 151 (2012).10.1016/j.vibspec.2012.02.019Suche in Google Scholar

46. Psareva, T. S., Zakutevrskgy, O. I., Chubar, M. I., Strelko, V. V., Shaposhnikova, T. O., Carvalho, J. R., Correia, M. J. W.: Uranium sorption on cork biomass. Colloids Surf. A Physiocochem. Eng. Asp. 252, 231 (2005).10.1016/j.colsurfa.2004.10.115Suche in Google Scholar

47. Hu, H., Wang, Z., Pan, L.: Synthesis of monodisperse Fe3O4@silica core–shell microspheres and their application for removal of heavy metal ions from water. J. Alloy Comp. 492, 656 (2010).10.1016/j.jallcom.2009.11.204Suche in Google Scholar

48. Fan, F., Qin, Z., Bai, J., Rong, W., Fan, F. Y., Tian, W., Wu, X., Wang, Y., Zhao, L.: Rapid removal of uranium from aqueous solutions using magnetic Fe3O4@SiO2 composite particles. J. Environ. Radioactiv. 106, 40 (2012).10.1016/j.jenvrad.2011.11.003Suche in Google Scholar

49. Krestou, A., Panias, D.: Uranium (VI) speciation diagrams in the UO2 2+/CO3 2-/H2O system at 25°C. The European Journal of Mineral Processing and Environmental Protection. 4, 113 (2004).Suche in Google Scholar

50. Ho, Y. S., McKay, G.: Pseudo-second order model for sorption processes. Process Biochem. 34, 451 (1999).10.1016/S0032-9592(98)00112-5Suche in Google Scholar

51. Hameed, B. H., Salman, J. M., Ahmad, A. L.: Adsorption isotherm and kinetic modeling of 2, 4-D pesticide on activated carbon derived from date stones. J. Hazard. Mater. 163, 121 (2009).10.1016/j.jhazmat.2008.06.069Suche in Google Scholar PubMed

52. Frost, R. L., Daniel, L., Zhu, M. H. Y.: Synthesis and characterization of clay-supported titania photocatalysts. J. Colloid Interface Sci. 316, 72 (2007).10.1016/j.jcis.2007.08.023Suche in Google Scholar PubMed

53. Jiménez-Cedillo, M. J., Olguína, M. T., Fall, Ch.: Adsorption kinetic of arsenates as water pollutant oniron, manganese and iron–manganese-modified clinoptiloliterichtuffs. J. Hazard. Mater. 163, 939 (2009).10.1016/j.jhazmat.2008.07.049Suche in Google Scholar PubMed

54. Yusan, S. D., Erenturk, S. A.: Sorption behaviors of uranium (VI) ions on α-FeOOH. Desalination. 269, 58 (2011).10.1016/j.desal.2010.10.042Suche in Google Scholar

55. Sari, A., Mendil, D., Tuzen, M., Soylak, M.: Biosorption of palladium (II) from aqueoussolution by moss (Racomitriumlanuginosum) biomass: equilibrium, kinetic andthermodynamic studies. J. Hazard. Mater. 162, 874 (2009).10.1016/j.jhazmat.2008.05.112Suche in Google Scholar PubMed

56. Han, R., Zou, W., Wang, Y., Zhu, L.: Removal of uranium (VI) from aqueous solutions by manganese oxide coated zeolite: discussion of adsorption isotherms and pH effect. J. Environ. Radioact. 93, 127 (2007).10.1016/j.jenvrad.2006.12.003Suche in Google Scholar PubMed

57. Langmuir, I.: The constitution and fundamental properties of solids and liquids part I. Solids. J. Am. Chem. Soc. 38, 2221 (1916).10.1021/ja02268a002Suche in Google Scholar

58. Yang, C. H.: Statistical mechanical study on the Freundlich isotherm equation. J. Colloid Interface Sci. 208, 379 (1998).10.1006/jcis.1998.5843Suche in Google Scholar PubMed

59. Fungaro, D. A., Yamaura, M., Craesmeyer, G. R.: Uranium removal from aqueous solution by zeolite from fly ash-iron oxide magnetic nanocomposite. International Review of Chemical Engineering 4, 2035 (2012).10.4208/jams.032211.041211aSuche in Google Scholar

60. Bakatula, E. N., Mosai, A. K., Tutu, H.: Removal of uranium from aqueous solutions using ammonium-modified zeolite. S. Afr. J. Chem. 68, 165 (2015).10.17159/0379-4350/2015/v68a23Suche in Google Scholar

61. Bryant, D. E., Stewart, D. I., Kee, T. P., Barton, C. S.: Development of a functionalized polymer-coated silica for the removal of uranium from groundwater. Environ. Sci. Technol. 37, 4011 (2003).10.1021/es020178gSuche in Google Scholar PubMed

62. Venkatesan, K. A., Sukumaran, V., Antony, M. P., Rao, P. R. V.: Extraction of uranium by amine, amide and benzamide grafted covalently on silica gel. J. Radioanal. Nucl. Chem. 260, 443 (2004).10.1023/B:JRNC.0000028201.35850.72Suche in Google Scholar

63. Shuibo, X., Chun, Z., Xinghuo, Z., Jing, Y., Xiaojian, Z., Jingsong, W.: Removal of uranium (VI) from aqueous solution by adsorption of hematite. J. Environ. Radioact. 100, 162 (2009).10.1016/j.jenvrad.2008.09.008Suche in Google Scholar PubMed

64. Chen, B., Jin, W., Kong, L., Mai, X., Zheng, N., Zhong, Q., Liang, J., Chen D.: Adsorption of uranium from uranium mine contaminated water using phosphate rock apatite (PRA): isotherm, kinetic and characterization studies. Colloid. Surface. A 520, 612 (2017).10.1016/j.colsurfa.2017.01.055Suche in Google Scholar

65. Oyewo, O. A., Onyango, M. S., Wolkers dorfer, C.: Application of banana peels nanosorbent for the removal of radioactive minerals from real mine water. J. Environ. Radioact. 164, 369 (2016).10.1016/j.jenvrad.2016.08.014Suche in Google Scholar PubMed

66. Kausar, A., Bhatti, H. N., MacKinnon, G.: Equilibrium, kinetic and thermodynamic studies on the removal of U(VI) by low cost agricultural waste. Colloid. Surface. B 111, 124 (2013).10.1016/j.colsurfb.2013.05.028Suche in Google Scholar PubMed

67. Sprynskyy, M., Kovalchuk, I., Buszewski, B.: The separation of uranium ions by natural and modified diatomite from aqueous solution. J. Hazard. Mater. 181, 700 (2010).10.1016/j.jhazmat.2010.05.069Suche in Google Scholar PubMed

68. Nilchi, A., Dehaghan, T. S., Garmarodi, S. R.: Kinetics, isotherm and thermodynamics for uranium and thorium ions adsorption from aqueous solutions by crystalline tin oxide nanoparticles. Desalination 321, 67 (2013).10.1016/j.desal.2012.06.022Suche in Google Scholar

69. Humelnicu, D., Popovici, E., Dvininov, E., Mita, C.: Study on the retention of uranyl ions on modified clays with titanium oxide. J. Radioanal. Nucl. Chem. 279, 131 (2009).10.1007/s10967-007-7194-zSuche in Google Scholar

70. Syed, H. S.: Comparison studies adsorption of thorium and uranium on pure clay mineral and local Malaysian soil sediment. J. Radioanal. Nucl. Chem. 214, 11 (1999).10.1007/BF02347283Suche in Google Scholar

Supplemental Material:

The online version of this article (DOI: https://doi.org/10.1515/ract-2016-2723) offers supplementary material, available to authorized users.

Received: 2016-10-28
Accepted: 2017-3-13
Published Online: 2017-4-28
Published in Print: 2017-10-26

©2017 Walter de Gruyter GmbH, Berlin/Boston

Artikel in diesem Heft

  1. Frontmatter
  2. Activation cross section and isomeric cross-section ratio for the (n,2n) reaction on 132,134Ba
  3. Measurement of photo-neutron cross sections and isomeric yield ratios in the 89Y(γ,xn)89−x Y reactions at the bremsstrahlung end-point energies of 65, 70 and 75 MeV
  4. Production, separation and target preparation of 171Tm and 147Pm for neutron cross section measurements
  5. Solid phase extraction of uranium from phosphoric acid: kinetic and thermodynamic study
  6. Natural silica sand modified by calcium oxide as a new adsorbent for uranyl ions removal from aqueous solutions
  7. Radiochemical separation of 231Pa from siliceous cake prior to its determination by gamma ray spectrometry
  8. Investigation of selenium compounds as targets for 76,77Br production using protons of energies up to 34 MeV
  9. Attenuation properties of radiation shielding materials such as granite and marble against γ-ray energies between 80 and 1350 keV
  10. Controlled release fertilizers using superabsorbent hydrogel prepared by gamma radiation
https://doi.org/10.1515/ract-2016-2723
Schlagwörter für diesen Artikel
El-Zafarana silica sand; batch technique; calcium oxide; isotherm; kinetics; thermodynamic

Artikel in diesem Heft

  1. Frontmatter
  2. Activation cross section and isomeric cross-section ratio for the (n,2n) reaction on 132,134Ba
  3. Measurement of photo-neutron cross sections and isomeric yield ratios in the 89Y(γ,xn)89−x Y reactions at the bremsstrahlung end-point energies of 65, 70 and 75 MeV
  4. Production, separation and target preparation of 171Tm and 147Pm for neutron cross section measurements
  5. Solid phase extraction of uranium from phosphoric acid: kinetic and thermodynamic study
  6. Natural silica sand modified by calcium oxide as a new adsorbent for uranyl ions removal from aqueous solutions
  7. Radiochemical separation of 231Pa from siliceous cake prior to its determination by gamma ray spectrometry
  8. Investigation of selenium compounds as targets for 76,77Br production using protons of energies up to 34 MeV
  9. Attenuation properties of radiation shielding materials such as granite and marble against γ-ray energies between 80 and 1350 keV
  10. Controlled release fertilizers using superabsorbent hydrogel prepared by gamma radiation
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