The relatively poor settling characteristics of particles produced in moving bed biofilm reac-tor(MBBR)outline the importance of developing a fundamental understanding of the char-acterization and settleability of MBBR-produced solids.The influence of carrier geometric properties and different levels of biofilm thickness on biofilm characteristics,solids produc-tion,particle size distribution(PSD),and particle settling velocity distribution(PSVD)is eval-uated in this study.The analytical ViCAs method is applied to the MBBR effluent to assess the distribution of particle settling velocities.This method is combined with microscopy imaging to relate particle size distribution to settling velocity.Three conventionally loaded MBBR systems are studied at a similar loading rate of 6.0 g/(m2·day)and with different carrier types.The AnoxK? K5 carrier,a commonly used carrier,is compared to so-called thickness-restraint carriers,AnoxK? Z-carriers that are newly designed carriers to limit the biofilm thickness.Moreover,two levels of biofilm thickness,200 μm and 400 μm,are stud-ied using AnoxK? Z-200 and Z-400 carriers.Statistical analysis confirms that K5 carriers demonstrated a significantly different biofilm mass,thickness,and density,in addition to distinct trends in PSD and PSVD in comparison with Z-carriers.However,in comparison of thickness-restraint carriers,Z-200 carrier results did not vary significantly compared to the Z-400 carrier.The K5 carriers showed the lowest production of suspended solids(0.7±0.3 g-TSS/day),thickest biofilm(281.1±8.7 pm)and lowest biofilm density(65.0±1.5 kg/m3).The K5 effluent solids also showed enhanced settling behaviour,consisting of larger particles with faster settling velocities.

Raheleh Arabgol;Peter A.Vanrolleghem;Robert Delatolla

Department of Civil Engineering,University of Ottawa,161 Louis Pasteur,K1N 6N5 ON,Canada;ModelEAU,Département de génie civil et de génie des eaux,Université Laval,1065 av.de la Médecine,Québec,Canada

环境科学学报（英文版）

[1]Raheleh Arabgol;Peter A.Vanrolleghem;Robert Delatolla-.Influence of MBBR carrier geometrical properties and biofilm thickness restraint on biofilm properties,effluent particle size distribution,settling velocity distribution,and settling behaviour)[J].环境科学学报（英文版）,2022(12):138-149

settleability,PSVD,ViCAs,AnoxK

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