Film analysis of activated sludge microbial discs by the Taguchi method and grey relational analysis

Abstract

A biofilm model with substrate inhibition is proposed for the activated sludge growing discs of rotating biological contactor (RBC); this model is different from the steady-state biofilm model based on the Monod assumption. Both deep and shallow types of biofilms are examined and discussed. The biofilm models based on both Monod and substrate inhibition (Haldane) assumptions are compared. In addition, the relationships between substrate utilization rate, biofilm thickness, and liquid phase substrate concentration are discussed. The influence order of the factors that affect the biofilm thickness is studied and discussed by combining the Taguchi method and grey relational analysis. In this work, a Taguchi orthogonal table is used to construct the series that is needed for grey relational analysis to determine the influence priority of the four parameters S(B), kX(f), K(s), and K(i).

Multi-Objective Optimization of MRR, TWR and Radial Overcut of EDMed AISI D2 Tool Steel Using Response Surface Methodology, Grey Relational Analysis And Entropy Measurement

“…(8). For this study, the value of is selected as 0.5 [3], and the observed values were summarized in Table 4. Table 5 lists the grey relational coefficient and grade for each experiment of the experimental arrangement calculated by applying Eqs.…”

Biological Fixed Film Systems

“…The simulation was implemented to analyze the effects of various levels of transport limitation on a growing single-species biofilm. A mathematical model that simulates biofilm thickness, liquid phase substrate concentration, and substrate utilization rate in RBCs was developed (Chen and Syu, 2003 (Gheewala and Annachhatre, 2003). Inhibitions on biofilm growth due to substrate, secondary substrate, and product were considered.…”

Enhanced production of human Cytochrome P450 2C9 by Escherichia coli BL21(DE3)pLysS through the novel use of grey relational analysis and Plackett–Burman design

“…Results of GRA are based on original data and the calculations are simple and easy to understand. Grey system theory has been applied to various systems such as biofilm (Chen and Syu 2003), agronomy (Huang et al 2003), traditional Chinese medicine (Wang et al 2004), food industry and gastroenterology (Tan et al 2005). In the present study, a GRA calculation procedure is demonstrated step-by-step and results are compared with the results of PB design to analyze the grades of influence of the affecting factors on the yield of recombinant CYP2C9.…”