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Pilot-Scale Submerged Hollow Fibre Membrane Bioreactor Thickening Operation: Membrane Clogging, Sustainable Flux and Sludge Characteristics Assessment


Affiliations
1 College of Energy and Environmental Engineering, Hebei University of Engineering, Handan, 056038, China
2 Graduate School, Hebei University of Engineering, Handan, 056038, China
 

The sludge characteristics and their impact on membrane clogging propensity and flux behaviours by statistical analyses were investigated in a pilot-scale hollow fiber membrane bioreactor during thickening operation at constant F/M ratio of 0.13. The cleaning efficiencies by chemical enhanced backflushing (CEB) and mechanical declogging at different mixed liquor suspended solids (MLSS) concentration and flux levels were further assessed through (post-cleaning) permeability decline rates. The results showed that MLSS concentration exerted the greatest impacts on the ratio of accumulated solids to mixed liquor solids loading (ΔK) and sustainable flux (JSUS), and its measurement could be used to predict both ΔK and JSUS, with a strong correlation between ΔK and JSUS observed. Moreover, membrane permeability recovery exhibited strong dependence on MLSS concentration and operational flux. On the premise of sub-critical flux operation, the recovered permeability can be sustained with a standard chemical enhanced backflushing (CEB) or declogging combined CEB at low (~8 g/L) or high (20-32 g/L) MLSS concentrations. However, the recovered permeability could only be obtained instantaneously regardless of cleaning modes when operation is exposed to super-critical flux condition, indicating the significance of the operational flux on membrane permeability sustainability.

Keywords

Membrane Bioreactor, Clogging, Sustainable Flux, Sludge Characteristics, Cleaning.
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  • APHA 1998. Standard Methods for the Examination of Water and Wastewater. 20th Edn., Edited by American Public Health Association, Washington, DC.

  • Buzatu, P., Zsirai, T., Aerts, P. and Judd, S. 2012. Permeability and clogging in an immersed hollow fibre membrane bioreactor. J. Membr. Sci., 421-422: 342-348.

  • Chang, I.S., Le-Clech, P., Jefferson, B. and Judd, S. 2002. Membrane fouling in membrane bioreactors for wastewater treatment. J. Environ. Eng., 128(11): 1018-1029.

  • Domínguez, L., Cases, V., Birek, C., Rodríguez, M. and Prats, D. 2012. Influence of organic loading rate on the performance of ultrafiltration and microfiltration membrane bioreactors at high sludge retention time. Chemical Engineering Journal, 181: 132143.

  • Gabarrón, S., Gómez, M., Dvoøák, L., Rùžièková, I., RodriguezRoda, I. and Comas, J. 2014. Ragging in MBR: effects of operational conditions, chemical cleaning, and pre-treatment improvements. Separation Science and Technology, 49: 2115-2123.

  • Judd, S. 2016. The status of industrial and municipal effluent treatment with membrane bioreactor technology. Chemical Engineering Journal, 305: 37-45.

  • Le-Clech, P., Chen, V. and Fane, T. 2006. Fouling in membrane bioreactors used in wastewater treatment. Journal of Membrane Science, 284: 17-53.

  • Li, J.F., Yang, F.L., Li, Y.Z., Wong, F.S. and Chua, H.C. 2008. Impact of biological constituents and properties of activated sludge on membrane fouling in a novel submerged membrane bioreactor.

  • Desalination, 225(1-3): 356-365.

  • Meng, F.G., Zhang, S. Q., Oh, Y., Zhou, Z.B., Sin, H.S. and Chae, S.Y. 2017. Fouling in membrane bioreactors: An updated review. Water Research, 114: 151-180.

  • Morgan, J.W., Forster, C.F. and Evison, L. 1990. A comparative study of the nature of biopolymers extracted from anaerobic and activated sludges. Water Res., 24: 743-750.

  • Sabia, G., Ferraris, M. and Spagni, A. 2013. Effect of solid retention time on sludge filterability and biomass activity: Long-term experiment on a pilot-scale membrane bioreactor treating municipal wastewater. Chemical Engineering Journal, 221: 176-184.

  • Santos, A., Ma, W. and Judd, S.J. 2011. Membrane bioreactors: two decades of research and implementation. Desalination, 273: 148-154.

  • Wang, X.H., Wu, Z.C., Wang, Z.W., Du X.Z. and Hua, J. 2008. Membrane fouling mechanisms in the process of using flat-sheet membrane for simultaneous thickening and digestion of activated sludge.

  • Separation and Purification Technology, 63: 676-683.

  • Zsirai, T., Aerts, P. and Judd, S. 2013. Reproducibility and applicability of the flux step test for a hollow fibre membrane bioreactor. Separation and Purification Technology, 107: 144-149.

  • Zsirai, T., Buzatu, P., Aerts, P. and Judd, S. 2012. Efficacy of relaxation, backflushing, chemical cleaning and clogging removal for an immersed hollow fibre membrane bioreactor. Water Res., 46(14): 4499-4507.


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  • Pilot-Scale Submerged Hollow Fibre Membrane Bioreactor Thickening Operation: Membrane Clogging, Sustainable Flux and Sludge Characteristics Assessment

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Authors

Zhaozhao Wang
College of Energy and Environmental Engineering, Hebei University of Engineering, Handan, 056038, China
Kai Zhang
College of Energy and Environmental Engineering, Hebei University of Engineering, Handan, 056038, China
Lina Yan
Graduate School, Hebei University of Engineering, Handan, 056038, China
Fengbing Tang
College of Energy and Environmental Engineering, Hebei University of Engineering, Handan, 056038, China
Wei Zhang
College of Energy and Environmental Engineering, Hebei University of Engineering, Handan, 056038, China
Simin Li
College of Energy and Environmental Engineering, Hebei University of Engineering, Handan, 056038, China

Abstract


The sludge characteristics and their impact on membrane clogging propensity and flux behaviours by statistical analyses were investigated in a pilot-scale hollow fiber membrane bioreactor during thickening operation at constant F/M ratio of 0.13. The cleaning efficiencies by chemical enhanced backflushing (CEB) and mechanical declogging at different mixed liquor suspended solids (MLSS) concentration and flux levels were further assessed through (post-cleaning) permeability decline rates. The results showed that MLSS concentration exerted the greatest impacts on the ratio of accumulated solids to mixed liquor solids loading (ΔK) and sustainable flux (JSUS), and its measurement could be used to predict both ΔK and JSUS, with a strong correlation between ΔK and JSUS observed. Moreover, membrane permeability recovery exhibited strong dependence on MLSS concentration and operational flux. On the premise of sub-critical flux operation, the recovered permeability can be sustained with a standard chemical enhanced backflushing (CEB) or declogging combined CEB at low (~8 g/L) or high (20-32 g/L) MLSS concentrations. However, the recovered permeability could only be obtained instantaneously regardless of cleaning modes when operation is exposed to super-critical flux condition, indicating the significance of the operational flux on membrane permeability sustainability.

Keywords


Membrane Bioreactor, Clogging, Sustainable Flux, Sludge Characteristics, Cleaning.

References