DOI QR코드

DOI QR Code

Carbon Nanosphere Composite Ultrafiltration Membranes with Anti-Biofouling Properties and More Porous Structures for Wastewater Treatment Using MBRs

분리막 생물반응기를 활용한 폐수처리를 위한 생물오염방지 특성 및 다공성 구조를 가진 탄소나노구체 복합 한외여과막

  • Jaewoo Lee (Department of Polymer-Nano Science and Technology, Jeonbuk National University)
  • 이재우 (전북대학교 고분자나노공학과)
  • Received : 2023.12.10
  • Accepted : 2023.12.21
  • Published : 2024.02.29

Abstract

Wastewater treatment using membrane bioreactors has been extensively used to alleviate water shortage and pollution by improving the quality of the treated water discharged into the environment. However, membrane biofouling persistently holds back an MBR process by reducing the process efficiency. Herein, we synthesized carbon nanospheres (CNSs) with many hydrophilic oxygen groups and utilized them as an additive to prepare high-performance ultrafiltration (UF) membranes with hydrophilicity and porous pore structure. CNSs were found to form crescent-shaped pores on the membrane surface, increasing the mean surface pore size by about 40% without causing significant defects larger than bubble points, as the CNS content increased by 4.6 wt%. In addition, the porous pore structure of CNS composite membranes was also attributable to the CNS's isotropic morphologies and relatively low particle number density because the aforementioned properties contributed to preventing the polymer solution viscosity from soaring with the loading of CNS. However, too porous structure compromised the mechanical properties, such that CNS2.3 was the best from a comprehensive consideration including the pore structure and mechanical properties. As a result, CNS2.3 showed not only 2 times higher water permeability than CNS0 but also 5 times longer operation duration until membrane cleaning was required.

본 연구에서는 분리막 생물반응기(membrane bioreactor, MBR)에서 발생되는 생물막오염 완화에 탁월한 효과를 가진 분리막을 개발할 목적으로, 친수성 산소 기능기가 많은 탄소나노구체(carbon nanosphere, CNS)를 합성한 뒤, 이를 첨가제로 활용하여 친수성과 다공성 기공 구조를 갖는 고성능 한외여과막을 제조하였다. CNS는 막 표면에 초승달 모양의 기공을 형성하였고, CNS 함량을 4.6 wt%까지 증가시킴에 따라 최대기공 크기보다 큰 결함을 야기하지 않으면서 평균 표면 기공 크기를 약 40% 증가시키는 것으로 나타났다. 또한, CNS 복합막의 다공성 기공 구조는 CNS의 등방성 형태와 상대적으로 낮은 입자 수밀도 덕분에 CNS 첨가에 따른 고분자 용액의 점도 급등이 방지됐기 때문이라고 판단된다. 그러나 너무 다공성이 커지게 되면 기계적 물성이 저하되므로, 기공구조와 기계적 성질을 포함한 종합적인 고려를 했을 때 CNS2.3이 가장 우수하다고 관측되었다. CNS2.3은 CNS0에 비해 수투과도가 2배 이상 높을 뿐만 아니라, MBR 공정에서 분리막 세정이 요구될 때까지의 운전 시간도 5배 이상 연장시킨 것으로 확인되었다.

Keywords

Acknowledgement

This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (grant number: 2021R1I1A3044565). This work was also supported by the Commercialization Promotion Agency for R&D Outcomes (COMPA) grant funded by the Korean Government (Ministry of Science and ICT) (RS-2023-00304743).

References

  1. J. Lee, J. H. Jang, H.-R. Chae, S. H. Lee, C.-H. Lee, P.-K. Park, Y.-J. Won, and I.-C. Kim, "A facile route to enhance the water flux of a thin-film composite reverse osmosis membrane: incorporating thickness-controlled graphene oxide into a highly porous support layer", J. Mater. Chem. A, 3, 22053-22060 (2015). https://doi.org/10.1039/C5TA04042F
  2. J. Lee, F. Zhou, K. Baek, W. Kim, H. Su, K. Kim, R. Wang, and T.-H. Bae, "Use of rigid cucurbit 6. uril mediating selective water transport as a potential remedy to improve the permselectivity and durability of reverse osmosis membranes", J. Membr. Sci., 623, 119017 (2021).
  3. J. Lee, C. Ahn, S. Chang, J. Lee, and T.-H. Bae, "Overcoming the trade-off between water flux and salt rejection of an RO membrane via simultaneous optimization using highly porous microstructured support and sulfonated porous organic polymer-based polyamide active layer", J. Membr. Sci., 687, 122085 (2023).
  4. Y. J. Lim, J. Lee, T.-H. Bae, J. Torres, and R. Wang, "Feasibility and performance of a thin-film composite seawater reverse osmosis membrane fabricated on a highly porous microstructured support", J. Membr. Sci., 611, 118407 (2020).
  5. S. Lee, H.-J. Kim, M. Tian, G. Khang, H.-W. Kim, T.-H. Bae, and J. Lee, "Silk fibroin-coated polyamide thin-film composite membranes with anti-scaling properties", Desalination, 546, 116195 (2023).
  6. Z. M. Ghazi, S. W. F. Rizvi, W. M. Shahid, A. M. Abdulhameed, H. Saleem, and S. J. Zaidi, "An overview of water desalination systems integrated with renewable energy sources", Desalination, 542, 116063 (2022).
  7. J. Lee, Y.-J. Won, D.-C. Choi, S. Lee, P.-K. Park, K.-H. Choo, H.-S. Oh, and C.-H. Lee, "Micro-patterned membranes with enzymatic quorum quenching activity to control biofouling in an MBR for wastewater treatment", J. Membr. Sci., 592, 117365 (2019).
  8. W. Rongwong, J. Lee, K. Goh, H. E. Karahan, and T.-H. Bae, "Membrane-based technologies for post-treatment of anaerobic effluents", npj Clean Water, 1, 21 (2018).
  9. J. He, S. Xia, W. Li, J. Deng, Q. Lin, and L. Zhang, "Resource recovery and valorization of food wastewater for sustainable development: An overview of current approaches", J. Environ. Manage., 347, 119118 (2023).
  10. S.-H. Yoon, "Membrane bioreactor processes: Principles and applications", CRC press, Boca Raton, United States (2015).
  11. S.-H. Yoon, C.-H. Lee, K.-J. Kim, and A. G. Fane, "Three-dimensional simulation of the deposition of multi-dispersed charged particles and prediction of resulting flux during cross-flow microfiltration", J. Membr. Sci., 161, 7-20 (1999). https://doi.org/10.1016/S0376-7388(99)00049-6
  12. M. C. Porter, "Concentration polarization with membrane ultrafiltration", Ind. Eng. Chem. Prod. Res. Dev., 11, 234-248 (1972).
  13. G. Segre and A. Silberberg, "Behaviour of macroscopic rigid spheres in Poiseuille flow Part 1. Determination of local concentration by statistical analysis of particle passages through crossed light beams", J. Fluid Mech., 14, 115-135 (1962). https://doi.org/10.1017/S002211206200110X
  14. G. Segre and A. Silberberg, "Behaviour of macroscopic rigid spheres in Poiseuille flow Part 2. Experimental results and interpretation", J. Fluid Mech., 14, 136-157 (1962). https://doi.org/10.1017/S0022112062001111
  15. J. Lee, H.-R. Chae, Y. J. Won, K. Lee, C.-H. Lee, H. H. Lee, I.-C. Kim, and J.-m. Lee, "Graphene oxide nanoplatelets composite membrane with hydrophilic and antifouling properties for wastewater treatment", J. Membr. Sci., 448, 223-230 (2013). https://doi.org/10.1016/j.memsci.2013.08.017
  16. X. Song, P. Gunawan, R. Jiang, S. S. J. Leong, K. Wang, and R. Xu, "Surface activated carbon nano-spheres for fast adsorption of silver ions from aqueous solutions", J. Hazard. Mater., 194, 162-168 (2011). https://doi.org/10.1016/j.jhazmat.2011.07.076
  17. H. M. Tran, D. Kwak, U. Lee, S. Chang, D. T. Tran, and J. Lee, "A hydrophilic near dissolved organic matter microfiltration (NDOM MF) membrane prepared using multifunctional porogen synthesized via metal-free atom transfer radical polymerization for highly efficient microplastic removal", Chem. Eng. J., 480, 147564 (2023).
  18. J. Lee, Y. J. Lim, J. H. Low, S. M. Lee, C.-H. Lee, R. Wang, and T.-H. Bae, "Synergistic effect of highly porous microstructured support and co-solvent assisted interfacial polymerization on the performance of thin-film composite FO membranes", Desalination, 539, 115947 (2022).
  19. H. E. Karahan, K. Goh, C. J. Zhang, E. Yang, C. Yildirim, C. Y. Chuah, M. G. Ahunbay, J. Lee, S. B. Tantekin-Ersolmaz, Y. Chen, and T. H. Bae, "MXene materials for designing advanced separation membranes", Adv. Mater., 32, e1906697 (2020).
  20. Q. Zhang, J. Wang, Z. Zhou, K. Huo, M. Dou, C. Han, X. Wang, S. M. Hasan, and B. Gao, "Preparation of GO@ DCN nanocomposite modified PVDF membranes for improved membrane performance and exploration of formation mechanism", J. Membr. Sci., 683, 121859 (2023).
  21. J. Lee, R. Wang, and T.-H. Bae, "High-performance reverse osmosis membranes fabricated on highly porous microstructured supports", Desalination, 436, 48-55 (2018). https://doi.org/10.1016/j.desal.2018.01.037
  22. H. Lee, W. B. Krantz, and S.-T. Hwang, "A model for wet-casting polymeric membranes incorporating nonequilibrium interfacial dynamics, vitrification and convection", J. Membr. Sci., 354, 74-85 (2010). https://doi.org/10.1016/j.memsci.2010.02.066
  23. K. Ho, Y. Teow, A. Mohammad, W. Ang, and P. Lee, "Development of graphene oxide (GO)/multi-walled carbon nanotubes (MWCNTs) nanocomposite conductive membranes for electrically enhanced fouling mitigation", J. Membr. Sci., 552, 189-201 (2018). https://doi.org/10.1016/j.memsci.2018.02.001
  24. A. Khan, T. A. Sherazi, Y. Khan, S. Li, S. A. R. Naqvi, and Z. Cui, "Fabrication and characterization of polysulfone/modified nanocarbon black composite antifouling ultrafiltration membranes", J. Membr. Sci., 554, 71-82 (2018). https://doi.org/10.1016/j.memsci.2018.02.063
  25. J. Wei, Y. Li, L. Setiawan, and R. Wang, "Influence of macromolecular additive on reinforced flat-sheet thin film composite pressure-retarded osmosis membranes", J. Membr. Sci., 511, 54-64 (2016). https://doi.org/10.1016/j.memsci.2016.03.046
  26. A. M. Wierenga, A. P. J. C. Philipse, S. A. Physicochemical, and E. Aspects, "Low-shear viscosity of isotropic dispersions of (Brownian) rods and fibres; A review of theory and experiments, Colloids Surf. A Physicochem. Eng. Asp., 137, 355-372 (1998). https://doi.org/10.1016/S0927-7757(97)00262-8
  27. J. Lee, H. Yoon, J. H. Yoo, D.-C. Choi, C. H. Nahm, S. H. Lee, H.-R. Chae, Y. H. Kim, C.-H. Lee, and P.-K. Park, "Influence of the sublayer structure of thin-film composite reverse osmosis membranes on the overall water flux", Environ. Sci. Water Res. Technol., 4, 1912-1922 (2018). https://doi.org/10.1039/C8EW00508G
  28. L. Nie, K. Goh, Y. Wang, J. Lee, Y. Huang, H. E. Karahan, K. Zhou, M. D. Guiver, and T. H. Bae, "Realizing small-flake graphene oxide membranes for ultrafast size-dependent organic solvent nanofiltration", Sci. Adv., 6, eaaz9184 (2020).
  29. U. Lee, E. S. Jang, S. Lee, H. J. Kim, C. W. Kang, M. Cho, and J. Lee, "Near dissolved organic matter microfiltration (NDOM MF) coupled with UVC LED disinfection to maximize the efficiency of water treatment for the removal of Giardia and Cryptosporidium", Water Res., 233, 119731 (2023).