Two-step Biofilm Kinetics and Characteristics of Conventional and Tapered Anaerobic Fluidized-Bed Bioreactors

• Main Authors: Yan, Jii-Liaq, 顏己喨
• Other Authors: Huang Ju-Sheng
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/05404768598724038585

碩士 === 國立成功大學 === 環境工程學系 === 84 === Two-step Biofilm Kinetics and Characteristics of Conventional and Tapered Anaerobic Fluidized-Bed BioreactorsGraduate Student: Jii-Liaq Yan Advisor: Ju-Sheng HuangABSTRACT In order to compare the differences of the characteristics and performance of conventional and tapered fluidized-bed bioreactors, the two- step biokinetic models including biofilm model and reactor model (of CSTR) were derived for the simulation purpose. Thereafter, the experimental results obtained were used to verify the proposed models. One set of the conventional fluidized-bed bioreactor and three sets of tapered fluidized-bed bioreactors with taper angles of 2.5o, 5o and 10o were used to treat the sucrose-containing synthetic wastewater. The substrate concentrations of bulk solution at various cross-section of bioreactor, the biofilm thickness, and the specific biomass in the lower-, central- and upper-part of bioreactor were measured once the bioreactor reached steady state. Meanwhile, the weight-loss of activated carbon from biorea If the geometric shape of conventinal bioreactor (i.e. identical cross-sectional area) is modified to the tapered one (i.e. narrower at the lower part and wider at the upper part), the wash-out of bioparticles from the bioreactor can be remarkably mitigated. Excepting the taper angle of 10o, the arithmetic mean of biofilm thickness of the later is thicker than the former (86.6 mm), especially for the taper angle of 5o (103.9 mm). The biomass concentration significantly increases with the increasing tape Moreover, the flow regime of conventional and tapered bioreacotrs determined by tracer study are close to CSTR, and the axial mixing of the later is more violent than the former. In addition, by using the suspended-growth batch reactor, the Monod type biokinetic constants of k1, Ks1, k2, Ks2 found are 28.5 mg-Sucrose/mg- VSS-day, 145mg-Sucrose/l, 3.28 mg-CH3COOH/mg-VSS-day, and 484 mg-CH3COOH/l, respectively. The distributed fractions of acidogenic bacteria and aceticlastic methanogens in the biofilm aKey words: anaerobic fluidized-bed bioreactor, taper angle, two-step biokinetic model, flow regime, substrate sucrose, biofilm characteristics, distributed fraction of acidogenic bacteria and aceticlastic methanogens, model verification.