title: [Characteristics of biofilm phase during the long-term degradation of a toluene-contaminated gas stream using BTF].
abstract: This study analyzes the accumulation and distribution of biomass and changes in properties of biofilm in a long-term biotrickling filter (BTF) system in order to investigate the correlation between the biofilm phase properties and the performance. After a long-term operation of 130 days, the BTF showed a deterioration in degradation performance and an increase in pressure drop with a gradual increase of biofilm thickness and uneven distribution of biomass. Meanwhile, the porosity of the upper and lower layers decreased from 85% and 82% in the start-up period to 65% and 40%, respectively, as a result of the excessive accumulation of biomass and its non-uniform distribution. The AWCD values showed a decreasing trend indicating that the biological activity decreased with the aging of biofilm in the long-term BTF. The contents of total extracellular polymeric substances (EPS) and protein in the later period were twice as much as those in the start-up period. The value of protein to polysaccharide (PN/PS) ratio increased from 0.3 to 0.95, and showed positive correlation with the surface hydrophobicity of the biofilm, which increased from 33% to 73% accordingly. The mean molecular weight of EPS decreased during the operation of BTF. The result of FTIR further showed that the main chemical composition of EPS changed in the long-term BTF accordingly, possibly resulting in the deterioration of performance in the long-term BTF. The above experimental results could be very helpful for reducing the clogging and performance deterioration in long-term BTF.
authors.affiliation: College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, China. gasinghj@163.com
authors.forename: Jun
authors.initials: J
authors.lastname: Hu
authors.forename: Jiang-Ling
authors.initials: JL
authors.lastname: Zheng
authors.forename: Yue-Xin
authors.initials: YX
authors.lastname: Wu
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Zhang
authors.forename: Jian-Meng
authors.initials: JM
authors.lastname: Chen
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000517:prevention & control*; D001673:Biodegradation, Environmental; D018441:Biofilms; D019149:Bioreactors; D002681:China; D005374:Filtration / Q000295:instrumentation; D014050:Toluene / Q000032:analysis*; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D055549:Volatile Organic Compounds; D014050:Toluene