Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 8
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

The present study investigated the relationship between social support, self-supportive behaviors, health risk behaviors, and daily activities of Turkish university students during the first wave of the Coronavirus Disease 2019 pandemic. We aimed to reveal how an unexpected global crisis may affect the association between social indicators and health risk behaviors among university students. As part of a large international study, a total of 7,125 university students (71% female) with a mean age of 23.50 ( SD = 6.08) from eight universities in Türkiye responded to an online survey during May 2020. Having a romantic relationship and significant other made a difference in students' health risk behaviors and daily activity indicators before and during the pandemic. Self-supportive behaviors and social contact predicted health risk behaviors and daily activity indicators, which differed according to residence location during the pandemic. Findings showed that Turkish university students' health risk behaviors and daily activity choices were influenced not only by the limitations of the pandemic but also individual behaviors and conditions as well as social relationships.
Go to article

Authors and Affiliations

Gülden Erden
1
Sami Çoksan
2
ORCID: ORCID
Asil Ali Özdoğru
3
ORCID: ORCID
Aysun Ergül-Topçu
4
Yakup Azak
5
Gözde Kıral Uçar
6
Hale Ögel-Balaban
7
İlkiz Altınoğlu Dikmeer
4
Yeşim Yasak
4

  1. Beykoz University, İstanbul, Türkiye
  2. Erzurum Technical University, Erzurum, Türkiye
  3. Üsküdar University, Istanbul, Türkiye
  4. Çankırı Karatekin University, Çankırı, Türkiye
  5. Tekirdağ Namık Kemal University, Tekirdağ, Türkiye
  6. Çanakkale Onsekiz Mart University, Çanakkale, Türkiye
  7. Bahçeşehir University, Istanbul, Türkiye
Download PDF Download RIS Download Bibtex

Abstract

An organobentonite modified with an amphoteric surfactant, tallow dihydroxyethyl betaine (TDHEB), was used as an adsorbent to simultaneously remove Cu(II) and phenol from wastewater. The characteristic of the organobentonite (named TDHEB-bentonite) was analyzed by X-ray diffraction, Fourier-transform infrared spectra and nitrogen adsorption-desorption isotherm. Batch tests were conducted to evaluate the adsorption capacities of TDHEB-bentonite for the two contaminants. Experiment results demonstrated that the adsorption of both contaminants is highly pH-dependent under acidic conditions. TDHEB-bentonite had about 2.0 and 5.0 times higher adsorption capacity toward Cu(II) and phenol, respectively, relative to the corresponding raw Na-bentonite. Adsorption isotherm data showed that the adsorption processes of both contaminants were well described by Freundlich model. Kinetic experiment demonstrated that both contaminants adsorption processes correlated well with pseudo-second-order model. Cu(II) had a negative impact on phenol adsorption, but not vice versa. Cu(II) was removed mainly through chelating with the organic groups (-CH2CH2OH and -COO-) of TDHEB. Otherwise, partition into the organic phase derived from the adsorbed surfactant was the primarily mechanism for phenol removal. Overall, TDHEB-bentonite was a promising adsorbent for removing Cu(II) and phenol simultaneously from wastewater.
Go to article

Bibliography

  1. Andronico, M. & Bajda, T. (2019). Modification of Bentonite with Cationic and Nonionic Surfactants: Structural and Textural Features. Materials, 12(22), 3772. DOI:10.3390/ma12223772
  2. Banat, F. A., Al-Bashir, B., Al-Asheh, S. & Hayajneh, O. (2000). Adsorption of phenol by bentonite. Environmental Pollution, 107(3), pp. 391-398. DOI:10.1016/S0269-7491(99)00173-6
  3. Bhattacharyya, K. G. & Gupta, S. S. (2008). Adsorption of a few heavy metals on natural and modified kaolinite and montmorillonite: A review. Advances in Colloid and Interface Science, 140(2), pp. 114-131. DOI:10.1016/j.cis.2007.12.008
  4. Cao, L., Li, Z., Xiang, S., Huang, Z., Ruan, R. & Liu, Y. (2019). Preparation and characteristics of bentonite–zeolite adsorbent and its application in swine wastewater. Bioresource Technology, 284, pp. 448-455. DOI:10.1016/j.biortech.2019.03.043
  5. Chen, H., Zhou, W., Zhu, K., Zhan, H. & Jiang, M. (2004). Sorption of ionizable organic compounds on HDTMA-modified loess soil. Science of The Total Environment, 326(1), pp. 217-223. DOI:10.1016/j.scitotenv.2003.12.011
  6. Chen, Y., Zhang, X., Wang, L., Cheng, X. & Shang, Q. (2020). Rapid removal of phenol/antibiotics in water by Fe-(8-hydroxyquinoline-7-carboxylic)/TiO2 flower composite: Adsorption combined with photocatalysis. Chemical Engineering Journal, 402, 126260. DOI:10.1016/j.cej.2020.126260
  7. Chu, Y., Khan, M. A., Xia, M., Lei, W., Wang, F., Zhu, S. & Yan, X. (2020). Synthesis and micro-mechanistic studies of histidine modified montmorillonite for lead(II) and copper(II) adsorption from wastewater. Chemical Engineering Research and Design, 157, pp. 142-152. DOI:10.1016/j.cherd.2020.02.020
  8. Díaz-Nava, M. C., Olguín, M. T. & Solache-Ríos, M. (2012). Adsorption of phenol onto surfactants modified bentonite. Journal of Inclusion Phenomena and Macrocyclic Chemistry, 74(1), 67-75. DOI:10.1007/s10847-011-0084-6
  9. Fan, H., Zhou, L., Jiang, X., Huang, Q. & Lang, W. (2014). Adsorption of Cu2+ and methylene blue on dodecyl sulfobetaine surfactant-modified montmorillonite. Applied Clay Science, 95, pp. 150-158. DOI:10.1016/j.clay.2014.04.001
  10. Freundlich, H. (1906). Over the adsorption in solution. The Journal of Physical Chemistry A, 57(385471), pp. 1100-1107. DOI:10.1515/zpch-1907-5723
  11. Griffin, R. A. & Shimp, N. F. (1976). Effect of pH on exchange-adsorption or precipitation of lead from landfill leachates by clay minerals. Environmental science & technology, 10(13), pp. 1256-1261. DOI:10.1021/es60123a003
  12. He, Y., Chen, Y., Zhang, K., Ye, W. & Wu, D. (2019). Removal of chromium and strontium from aqueous solutions by adsorption on laterite. Archives of Environmental Protection, 45(3), pp. 11-20. DOI:10.24425/aep.2019.128636
  13. Kong, Y., Wang, L., Ge, Y., Su, H. & Li, Z. (2019). Lignin xanthate resin–bentonite clay composite as a highly effective and low-cost adsorbent for the removal of doxycycline hydrochloride antibiotic and mercury ions in water. Journal of Hazardous Materials, 368, pp. 33-41. DOI:10.1016/j.jhazmat.2019.01.026
  14. Langmuir, I. (1918). The adsorption of gases on plane surfaces of glass, mica and platinum. Journal of the American Chemical society, 40(9), pp. 1361-1403. DOI:10.1021/ja02242a004
  15. Lee, C., Lee, S., Park, J., Park, C., Lee, S. J., Kim, S., An, B., Yun, S., Lee, S. & Choi, J. (2017). Removal of copper, nickel and chromium mixtures from metal plating wastewater by adsorption with modified carbon foam. Chemosphere, 166, pp. 203-211. DOI:10.1016/j.chemosphere.2016.09.093
  16. Lin, S. & Juang, R. (2002). Heavy metal removal from water by sorption using surfactant-modified montmorillonite. Journal of Hazardous Materials, 92(3), pp. 315-326. DOI:10.1016/S0304-3894(02)00026-2
  17. Liu, C., Wu, P., Zhu, Y. & Tran, L. (2016). Simultaneous adsorption of Cd2+ and BPA on amphoteric surfactant activated montmorillonite. Chemosphere, 144, pp. 1026-1032. DOI:10.1016/j.chemosphere.2015.09.063
  18. Long, H., Wu, P. & Zhu, N. (2013). Evaluation of Cs+ removal from aqueous solution by adsorption on ethylamine-modified montmorillonite. Chemical Engineering Journal, 225, pp. 237-244. DOI:10.1016/j.cej.2013.03.088
  19. Ma, J. & Zhu, L. (2006). Simultaneous sorption of phosphate and phenanthrene to inorgano–organo-bentonite from water. Journal of Hazardous Materials, 136(3), pp. 982-988. DOI:10.1016/j.jhazmat.2006.01.046
  20. Ma, J. & Zhu, L. (2007). Removal of phenols from water accompanied with synthesis of organobentonite in one-step process. Chemosphere, 68(10), pp. 1883-1888. DOI:10.1016/j.chemosphere.2007.03.002
  21. Ma, L., Chen, Q., Zhu, J., Xi, Y., He, H., Zhu, R., Tao, Q. & Ayoko, G. A. (2016). Adsorption of phenol and Cu(II) onto cationic and zwitterionic surfactant modified montmorillonite in single and binary systems. Chemical Engineering Journal, 283, pp. 880-888. DOI:10.1016/j.cej.2015.08.009
  22. Matthes, W., Madsen, F. T. & Kahr, G. (1999). Sorption of heavy-metal cations by Al and Zr-hydroxy-intercalated and pillared bentonite. Clays and Clay Minerals, 47(5), pp. 617-629. DOI:10.1346/CCMN.1999.0470508
  23. Meng, Z., Zhang, Y. & Zhang, Z. (2008). Simultaneous adsorption of phenol and cadmium on amphoteric modified soil. Journal of Hazardous Materials, 159(2), pp. 492-498. DOI:10.1016/j.jhazmat.2008.02.045
  24. Nourmoradi, H., Nikaeen, M. & Khiadani Hajian, M. (2012). Removal of benzene, toluene, ethylbenzene and xylene (BTEX) from aqueous solutions by montmorillonite modified with nonionic surfactant: Equilibrium, kinetic and thermodynamic study. Chemical Engineering Journal, 191, pp. 341-348. DOI:10.1016/j.cej.2012.03.029
  25. Pal, A., Jayamani, J. & Prasad, R. (2014). An urgent need to reassess the safe levels of copper in the drinking water: Lessons from studies on healthy animals harboring no genetic deficits. NeuroToxicology, 44, pp. 58-60. DOI:10.1016/j.neuro.2014.05.005
  26. Park, Y., Ayoko, G. A., Horváth, E., Kurdi, R., Kristof, J. & Frost, R. L. (2013). Structural characterisation and environmental application of organoclays for the removal of phenolic compounds. Journal of Colloid and Interface Science, 393, pp. 319-334. DOI:10.1016/j.jcis.2012.10.067
  27. Qu, Y., Qin, L., Liu, X. & Yang, Y. (2020). Reasonable design and sifting of microporous carbon nanosphere-based surface molecularly imprinted polymer for selective removal of phenol from wastewater. Chemosphere, 251, 126376. DOI:10.1016/j.chemosphere.2020.126376
  28. Redlich, O. & Peterson, D. L. (1959). A useful adsorption isotherm. Journal of physical chemistry, 63(6), 1024. DOI:10.1021/j150576a611
  29. Ren, S., Meng, Z., Sun, X., Lu, H., Zhang, M., Lahori, A. H. & Bu, S. (2020). Comparison of Cd2+ adsorption onto amphoteric, amphoteric-cationic and amphoteric-anionic modified magnetic bentonites. Chemosphere, 239, 124840. DOI:10.1016/j.chemosphere.2019.124840
  30. Senturk, H. B., Ozdes, D., Gundogdu, A., Duran, C. & Soylak, M. (2009). Removal of phenol from aqueous solutions by adsorption onto organomodified Tirebolu bentonite: Equilibrium, kinetic and thermodynamic study. Journal of Hazardous Materials, 172(1), pp. 353-362. DOI:10.1016/j.jhazmat.2009.07.019
  31. Taffarel, S. R. & Rubio, J. (2010). Adsorption of sodium dodecyl benzene sulfonate from aqueous solution using a modified natural zeolite with CTAB. Minerals Engineering, 23(10), pp. 771-779. DOI:10.1016/j.mineng.2010.05.018
  32. Tri, N. L. M., Thang, P. Q., Van Tan, L., Huong, P. T., Kim, J., Viet, N. M., Phuong, N. M. & Al Tahtamouni, T. M. (2020). Removal of phenolic compounds from wastewaters by using synthesized Fe-nano zeolite. Journal of Water Process Engineering, 33, 101070. DOI:10.1016/j.jwpe.2019.101070
  33. Veli, S. & Alyüz, B. (2007). Adsorption of copper and zinc from aqueous solutions by using natural clay. Journal of Hazardous Materials, 149(1), pp. 226-233. DOI:10.1016/j.jhazmat.2007.04.109
  34. Wang, G., Wang, X., Zhang, S., Ma, S., Wang, Y. & Qiu, J. (2020). Adsorption of heavy metal and organic pollutant by organo-montmorillonites in binary-component system. Journal of Porous Materials, 27(5), pp. 1515-1522. DOI:10.1007/s10934-020-00927-8
  35. Wang, G., Zhang, S., Hua, Y., Su, X., Ma, S., Wang, J., Tao, Q., Wang, Y. & Komarneni, S. (2017). Phenol and/or Zn2+ adsorption by single- or dual-cation organomontmorillonites. Applied Clay Science, 140, pp. 1-9. DOI:10.1016/j.clay.2017.01.023
  36. Yan, L., Shan, X., Wen, B. & Zhang, S. (2007). Effect of lead on the sorption of phenol onto montmorillonites and organo-montmorillonites. Journal of Colloid and Interface Science, 308(1), pp. 11-19. DOI:10.1016/j.jcis.2006.12.027
  37. Yang, G., Tang, L., Zeng, G., Cai, Y., Tang, J., Pang, Y., Zhou, Y., Liu, Y., Wang, J., Zhang, S. & Xiong, W. (2015). Simultaneous removal of lead and phenol contamination from water by nitrogen-functionalized magnetic ordered mesoporous carbon. Chemical Engineering Journal, 259, pp. 854-864. DOI:10.1016/j.cej.2014.08.081
  38. Yoo, J., Choi, J., Lee, T. & Park, J. (2004). Organobentonite for sorption and degradation of phenol in the presence of heavy metals. Water, Air, and Soil Pollution, 154(1), pp. 225-237. DOI:10.1023/B:WATE.0000022970.21712.64
  39. Yu, K., Xu, J., Jiang, X., Liu, C., McCall, W. & Lu, J. (2017). Stabilization of heavy metals in soil using two organo-bentonites. Chemosphere, 184, pp.884-891. DOI:10.1016/j.chemosphere.2017.06.040
  40. Zendelska, A., Golomeova, M., Golomeov, B. & Krstev, B. (2018). Removal of lead ions from acid aqueous solutions and acid mine drainage using zeolite bearing tuff. Archives of Environmental Protection, 44(1), pp. 87-96. DOI:10.24425/118185
  41. Zhu, R., Chen, Q., Zhou, Q., Xi, Y., Zhu, J. & He, H. (2016). Adsorbents based on montmorillonite for contaminant removal from water: A review. Applied Clay Science, 123, pp. 239-258. DOI:10.1016/j.clay.2015.12.024
  42. Andronico, M. & Bajda, T. (2019). Modification of Bentonite with Cationic and Nonionic Surfactants: Structural and Textural Features. Materials, 12(22), 3772. DOI:10.3390/ma12223772
  43. Banat, F. A., Al-Bashir, B., Al-Asheh, S. & Hayajneh, O. (2000). Adsorption of phenol by bentonite. Environmental Pollution, 107(3), pp. 391-398. DOI:10.1016/S0269-7491(99)00173-6
  44. Bhattacharyya, K. G. & Gupta, S. S. (2008). Adsorption of a few heavy metals on natural and modified kaolinite and montmorillonite: A review. Advances in Colloid and Interface Science, 140(2), pp. 114-131. DOI:10.1016/j.cis.2007.12.008
  45. Cao, L., Li, Z., Xiang, S., Huang, Z., Ruan, R. & Liu, Y. (2019). Preparation and characteristics of bentonite–zeolite adsorbent and its application in swine wastewater. Bioresource Technology, 284, pp. 448-455. DOI:10.1016/j.biortech.2019.03.043
  46. Chen, H., Zhou, W., Zhu, K., Zhan, H. & Jiang, M. (2004). Sorption of ionizable organic compounds on HDTMA-modified loess soil. Science of The Total Environment, 326(1), pp. 217-223. DOI:10.1016/j.scitotenv.2003.12.011
  47. Chen, Y., Zhang, X., Wang, L., Cheng, X. & Shang, Q. (2020). Rapid removal of phenol/antibiotics in water by Fe-(8-hydroxyquinoline-7-carboxylic)/TiO2 flower composite: Adsorption combined with photocatalysis. Chemical Engineering Journal, 402, 126260. DOI:10.1016/j.cej.2020.126260
  48. Chu, Y., Khan, M. A., Xia, M., Lei, W., Wang, F., Zhu, S. & Yan, X. (2020). Synthesis and micro-mechanistic studies of histidine modified montmorillonite for lead(II) and copper(II) adsorption from wastewater. Chemical Engineering Research and Design, 157, pp. 142-152. DOI:10.1016/j.cherd.2020.02.020
  49. Díaz-Nava, M. C., Olguín, M. T. & Solache-Ríos, M. (2012). Adsorption of phenol onto surfactants modified bentonite. Journal of Inclusion Phenomena and Macrocyclic Chemistry, 74(1), 67-75. DOI:10.1007/s10847-011-0084-6
  50. Fan, H., Zhou, L., Jiang, X., Huang, Q. & Lang, W. (2014). Adsorption of Cu2+ and methylene blue on dodecyl sulfobetaine surfactant-modified montmorillonite. Applied Clay Science, 95, pp. 150-158. DOI:10.1016/j.clay.2014.04.001
  51. Freundlich, H. (1906). Over the adsorption in solution. The Journal of Physical Chemistry A, 57(385471), pp. 1100-1107. DOI:10.1515/zpch-1907-5723
  52. Griffin, R. A. & Shimp, N. F. (1976). Effect of pH on exchange-adsorption or precipitation of lead from landfill leachates by clay minerals. Environmental science & technology, 10(13), pp. 1256-1261. DOI:10.1021/es60123a003
  53. He, Y., Chen, Y., Zhang, K., Ye, W. & Wu, D. (2019). Removal of chromium and strontium from aqueous solutions by adsorption on laterite. Archives of Environmental Protection, 45(3), pp. 11-20. DOI:10.24425/aep.2019.128636
  54. Kong, Y., Wang, L., Ge, Y., Su, H. & Li, Z. (2019). Lignin xanthate resin–bentonite clay composite as a highly effective and low-cost adsorbent for the removal of doxycycline hydrochloride antibiotic and mercury ions in water. Journal of Hazardous Materials, 368, pp. 33-41. DOI:10.1016/j.jhazmat.2019.01.026
  55. Langmuir, I. (1918). The adsorption of gases on plane surfaces of glass, mica and platinum. Journal of the American Chemical society, 40(9), pp. 1361-1403. DOI:10.1021/ja02242a004
  56. Lee, C., Lee, S., Park, J., Park, C., Lee, S. J., Kim, S., An, B., Yun, S., Lee, S. & Choi, J. (2017). Removal of copper, nickel and chromium mixtures from metal plating wastewater by adsorption with modified carbon foam. Chemosphere, 166, pp. 203-211. DOI:10.1016/j.chemosphere.2016.09.093
  57. Lin, S. & Juang, R. (2002). Heavy metal removal from water by sorption using surfactant-modified montmorillonite. Journal of Hazardous Materials, 92(3), pp. 315-326. DOI:10.1016/S0304-3894(02)00026-2
  58. Liu, C., Wu, P., Zhu, Y. & Tran, L. (2016). Simultaneous adsorption of Cd2+ and BPA on amphoteric surfactant activated montmorillonite. Chemosphere, 144, pp. 1026-1032. DOI:10.1016/j.chemosphere.2015.09.063
  59. Long, H., Wu, P. & Zhu, N. (2013). Evaluation of Cs+ removal from aqueous solution by adsorption on ethylamine-modified montmorillonite. Chemical Engineering Journal, 225, pp. 237-244. DOI:10.1016/j.cej.2013.03.088
  60. Ma, J. & Zhu, L. (2006). Simultaneous sorption of phosphate and phenanthrene to inorgano–organo-bentonite from water. Journal of Hazardous Materials, 136(3), pp. 982-988. DOI:10.1016/j.jhazmat.2006.01.046
  61. Ma, J. & Zhu, L. (2007). Removal of phenols from water accompanied with synthesis of organobentonite in one-step process. Chemosphere, 68(10), pp. 1883-1888. DOI:10.1016/j.chemosphere.2007.03.002
  62. Ma, L., Chen, Q., Zhu, J., Xi, Y., He, H., Zhu, R., Tao, Q. & Ayoko, G. A. (2016). Adsorption of phenol and Cu(II) onto cationic and zwitterionic surfactant modified montmorillonite in single and binary systems. Chemical Engineering Journal, 283, pp. 880-888. DOI:10.1016/j.cej.2015.08.009
  63. Matthes, W., Madsen, F. T. & Kahr, G. (1999). Sorption of heavy-metal cations by Al and Zr-hydroxy-intercalated and pillared bentonite. Clays and Clay Minerals, 47(5), pp. 617-629. DOI:10.1346/CCMN.1999.0470508
  64. Meng, Z., Zhang, Y. & Zhang, Z. (2008). Simultaneous adsorption of phenol and cadmium on amphoteric modified soil. Journal of Hazardous Materials, 159(2), pp. 492-498. DOI:10.1016/j.jhazmat.2008.02.045
  65. Nourmoradi, H., Nikaeen, M. & Khiadani Hajian, M. (2012). Removal of benzene, toluene, ethylbenzene and xylene (BTEX) from aqueous solutions by montmorillonite modified with nonionic surfactant: Equilibrium, kinetic and thermodynamic study. Chemical Engineering Journal, 191, pp. 341-348. DOI:10.1016/j.cej.2012.03.029
  66. Pal, A., Jayamani, J. & Prasad, R. (2014). An urgent need to reassess the safe levels of copper in the drinking water: Lessons from studies on healthy animals harboring no genetic deficits. NeuroToxicology, 44, pp. 58-60. DOI:10.1016/j.neuro.2014.05.005
  67. Park, Y., Ayoko, G. A., Horváth, E., Kurdi, R., Kristof, J. & Frost, R. L. (2013). Structural characterisation and environmental application of organoclays for the removal of phenolic compounds. Journal of Colloid and Interface Science, 393, pp. 319-334. DOI:10.1016/j.jcis.2012.10.067
  68. Qu, Y., Qin, L., Liu, X. & Yang, Y. (2020). Reasonable design and sifting of microporous carbon nanosphere-based surface molecularly imprinted polymer for selective removal of phenol from wastewater. Chemosphere, 251, 126376. DOI:10.1016/j.chemosphere.2020.126376
  69. Redlich, O. & Peterson, D. L. (1959). A useful adsorption isotherm. Journal of physical chemistry, 63(6), 1024. DOI:10.1021/j150576a611
  70. Ren, S., Meng, Z., Sun, X., Lu, H., Zhang, M., Lahori, A. H. & Bu, S. (2020). Comparison of Cd2+ adsorption onto amphoteric, amphoteric-cationic and amphoteric-anionic modified magnetic bentonites. Chemosphere, 239, 124840. DOI:10.1016/j.chemosphere.2019.124840
  71. Senturk, H. B., Ozdes, D., Gundogdu, A., Duran, C. & Soylak, M. (2009). Removal of phenol from aqueous solutions by adsorption onto organomodified Tirebolu bentonite: Equilibrium, kinetic and thermodynamic study. Journal of Hazardous Materials, 172(1), pp. 353-362. DOI:10.1016/j.jhazmat.2009.07.019
  72. Taffarel, S. R. & Rubio, J. (2010). Adsorption of sodium dodecyl benzene sulfonate from aqueous solution using a modified natural zeolite with CTAB. Minerals Engineering, 23(10), pp. 771-779. DOI:10.1016/j.mineng.2010.05.018
  73. Tri, N. L. M., Thang, P. Q., Van Tan, L., Huong, P. T., Kim, J., Viet, N. M., Phuong, N. M. & Al Tahtamouni, T. M. (2020). Removal of phenolic compounds from wastewaters by using synthesized Fe-nano zeolite. Journal of Water Process Engineering, 33, 101070. DOI:10.1016/j.jwpe.2019.101070
  74. Veli, S. & Alyüz, B. (2007). Adsorption of copper and zinc from aqueous solutions by using natural clay. Journal of Hazardous Materials, 149(1), pp. 226-233. DOI:10.1016/j.jhazmat.2007.04.109
  75. Wang, G., Wang, X., Zhang, S., Ma, S., Wang, Y. & Qiu, J. (2020). Adsorption of heavy metal and organic pollutant by organo-montmorillonites in binary-component system. Journal of Porous Materials, 27(5), pp. 1515-1522. DOI:10.1007/s10934-020-00927-8
  76. Wang, G., Zhang, S., Hua, Y., Su, X., Ma, S., Wang, J., Tao, Q., Wang, Y. & Komarneni, S. (2017). Phenol and/or Zn2+ adsorption by single- or dual-cation organomontmorillonites. Applied Clay Science, 140, pp. 1-9. DOI:10.1016/j.clay.2017.01.023
  77. Yan, L., Shan, X., Wen, B. & Zhang, S. (2007). Effect of lead on the sorption of phenol onto montmorillonites and organo-montmorillonites. Journal of Colloid and Interface Science, 308(1), pp. 11-19. DOI:10.1016/j.jcis.2006.12.027
  78. Yang, G., Tang, L., Zeng, G., Cai, Y., Tang, J., Pang, Y., Zhou, Y., Liu, Y., Wang, J., Zhang, S. & Xiong, W. (2015). Simultaneous removal of lead and phenol contamination from water by nitrogen-functionalized magnetic ordered mesoporous carbon. Chemical Engineering Journal, 259, pp. 854-864. DOI:10.1016/j.cej.2014.08.081
  79. Yoo, J., Choi, J., Lee, T. & Park, J. (2004). Organobentonite for sorption and degradation of phenol in the presence of heavy metals. Water, Air, and Soil Pollution, 154(1), pp. 225-237. DOI:10.1023/B:WATE.0000022970.21712.64
  80. Yu, K., Xu, J., Jiang, X., Liu, C., McCall, W. & Lu, J. (2017). Stabilization of heavy metals in soil using two organo-bentonites. Chemosphere, 184, pp.884-891. DOI:10.1016/j.chemosphere.2017.06.040
  81. Zendelska, A., Golomeova, M., Golomeov, B. & Krstev, B. (2018). Removal of lead ions from acid aqueous solutions and acid mine drainage using zeolite bearing tuff. Archives of Environmental Protection, 44(1), pp. 87-96. DOI:10.24425/118185
  82. Zhu, R., Chen, Q., Zhou, Q., Xi, Y., Zhu, J. & He, H. (2016). Adsorbents based on montmorillonite for contaminant removal from water: A review. Applied Clay Science, 123, pp. 239-258. DOI:10.1016/j.clay.2015.12.024
Go to article

Authors and Affiliations

Xiangyang Hu
1
Bao Wang
2
ORCID: ORCID
Gengsheng Yan
1
Bizhou Ge
2

  1. PowerChina Northwest Engineering Corporation Limited, China
  2. Xi’an University of Architecture and Technology, China
Download PDF Download RIS Download Bibtex

Abstract

In this study, the effects of replacing fine aggregate by granulated lead/zinc slag waste (GLZSW) on the thickness of concrete shields against X-ray radiation and on the compressive strength of concrete have been investigated. The fine aggregate was substituted by GLZSW in four percentages: 25%, 50%, 75%, and 100% (by weight). The first aim of the present study was to compare the thicknesses of concretes with GLZSW and control concrete using Lead Equivalent (LE). The second aim was to assess the effects of replacing fine aggregate by GLZSW on the compressive strength of concrete. Results of this study indicated that the compressive strength of mixed concretes increased significantly compared to the control upon replacing fine aggregate by GLZSW; the mixture containing 100% GLZSW had the greatest compressive strength. Further, the inclusion of GLZSW as a substitute for fine aggregate increased the radiation attenuation properties and consequently decreased the thickness of concrete shields in direct proportion to the mixing ratio of GLZSW. The results revealed that concrete mixes containing 100% GLZSW offered the greatest reduction in shield thickness. The study shows that there is a promising future for the use of GLZSW as substitute for fine aggregate in concrete used to shield against X-ray radiation.
Go to article

Authors and Affiliations

Mohamed Alwaeli
1

  1. Assoc. Prof., DSc., PhD., Eng., Mohamed Alwaeli, Silesian University of Technology, Faculty of Energy and Environmental Engineering, Konarskiego 18A, 44-100 Gliwice
Download PDF Download RIS Download Bibtex

Abstract

The mechanical characteristics of transversely isotropic rocks are significantly different under various levels of inclination, and it is difficult to describe exactly the mechanical behaviour of transversely isotropic rocks. Assuming that rock consists of a great deal of microelements, and the microelement strength controlled by Mohr–Coulomb criterion follows the log normal distribution. The elastic modulus is used to reflect the anisotropy of rock, and the weak patches stiffness model is verified and employed to depict the variation of elastic modulus with different inclination angle. Based on basic damage mechanics theory and statistical method, a nonlinear statistical empirical model for transversely isotropic rocks is proposed under uniaxial compressive condition. In order to verify the correctness of the proposed model, comparison analyses between predicted results and experimental data taken from published literature are carried out, which have good consistency. Finally, the discussions on the influences of the distribution parameters ��, �� and elastic modulus with different inclination angle, ����, on proposed model is offered.
Go to article

Authors and Affiliations

Yansheng Deng
1
ORCID: ORCID
Chenjie Shen
1
ORCID: ORCID
Baoping Zou
1
ORCID: ORCID

  1. School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, Hangzhou 310023, China
Download PDF Download RIS Download Bibtex

Abstract

Since 1978 the retreat of Ecology Glacier in the vicinity of Henryk Arctowski Station has opened new ice-free areas for colonization by terrestrial organisms initiated by pioneer microbes. Samples were collected from the soil surface, at 0, 5 and 20 cm below surface close to glacier front, then stored at below -20°C . Total bacterial count (TC), estimated by epifluorescence microscopy, reached high values, of 1010 g-1 dry wt. Healthy looking bacterial cells of mean volume 0.0209 µm3 at 0 cm to 0.0292 µm3 at 20 cm made up from 7% at 0 cm , to 30% at 20 cm of total bacterial population. The number of colony forming units (CFU) accounted for only 0.02% of TC. Taxonomically they belonged to the a, b, g subdivisions of the proteobacteria and to the Cytophaga-Flavobacterium-Bacteroides (CFB) group. Morphophysiologically CFU bacteria were diverse, from Gram variable short coccal forms to very long rods or filaments. Randomly selected CFU colonies were characterized by low sugar assimilation and high esterase/lipase activity. Spore forming bacteria – absent from 0 and 5 cm , formed a small fraction of 175 cells g-1 dry wt at the 20 cm depth. Filamentous fungi were relatively abundant and represented mainly by oligotrophs.

Go to article

Authors and Affiliations

Jakub Grzesiak
Magdalena Żmuda−Baranowska
Piotr Borsuk
Marek Zdanowski
Download PDF Download RIS Download Bibtex

Abstract

The international community is presently facing a new hazard in the form of oil spills from drilling platforms rather than ships. The issue was first brought to public attention in conjunction with the 2009 West Atlas rig fire that resulted in oil pollution of Indonesia and northern shores of Australia. The wrangle continues in the wake of the recent Deepwater Horizon disaster in the Gulf of Mexico.

As of today there are no international measures that regulate the issues of civil liability for offshore drilling related pollution. Indonesia has put forward the matter to the International Maritime Organisation; the IMO intends to draft a convention.

Civil liability for offshore drilling related pollution within domestic law is aseparate issue. In Polish law, Article 435 et seq of the Civil Code would apply. The pollution threat extends to the Baltic Sea, Northern Sea and other parts of the world.

The issue is also being examined by the European Union. The European Agency for the Maritime Safety has mandate to act in case of damage related to offshore drilling. Following the example of the American Oil Pollution Act (1990), the EU aims to draft comprehensive laws that would cover pollution associated with the entire mining industry.

Go to article

Authors and Affiliations

Paweł Krężel
Download PDF Download RIS Download Bibtex

Abstract

B a c k g r o u n d: Parechovirus and enterovirus belong to a family of Picornaviridae, nonenveloped, small-sized RNA viruses, responsible for multiple human diseases. Recent introduction of molecular tests enabled the identifi cation of parechovirus and enterovirus infections. Our aim was a retrospective analysis of signs and symptoms associated with confirmed parechovirus or enterovirus infections among children treated in the Department of Neonatology, St. Louis Regional Children’s Hospital in Kraków, Poland.

M e t h o d s: Based on laboratory records, we identified all cases of parecho- or enterovirus infections confirmed by identification of viral RNA in nasal swab or cerebrospinal fluid samples. Hospital records and laboratory tests results of selected patients were then analyzed, and selected data were summarized, with emphasis on clinical and laboratory findings at admission.

R e s u l t s: We identified 11 cases of parechovirus and three of enterovirus infections. All cases were neonates admitted to hospital with fever and irritability. Except for leukopenia in 50% of patients, no significant abnormalities were noted in blood counts and serum biochemistry, including low C-reactive protein and procalcitonin. In nine cases, cerebrospinal fluid was collected, the fluid protein concentrations and cell counts were moderately increased. Final diagnosis was meningitis in 12 children, and other viral infections in two.

C o n c l u s i o n s: Viral infection, including parecho- and enteroviruses, should be considered in the etiology of fever and meningitis in neonates. The available molecular tests allow for detection of viral genetic material even in a scant biological specimen collected from neonates.

Go to article

Authors and Affiliations

Małgorzata Kielar
Aleksandra Tokarz
Paulina Dumnicka
Małgorzata Maraj
Bożena Burzyńska
Stanisław Stępniewski

This page uses 'cookies'. Learn more