Modelling of submerged membrane bioreactor: Conceptual study about link between activated slugde biokinetics, aeration and fouling process

Abstract

A mathematical model was developed to simulate filtration process and aeration influence on Submerged Membrane Bioreactor (SMBR) in aerobic conditions. The biological kinetics and the dynamic effect of the sludge attachment and detachment from the membrane, in relation to the filtration and a strong intermittent aeration, were included in the model. The model was established considering soluble microbial products (SMP) formation-degradation. The fouling components responsible of pore clogging, sludge cake growth, and temporal sludge film coverage were considered during calculation of the total membrane fouling resistance. The influence of SMP, trans-membrane pressure, and mixed liquor suspended solids on specific filtration resistance of the sludge cake was also included. With this model, the membrane fouling under different SMBR operational conditions can be simulated. The influence of a larger number of very important process variables on fouling development can be well quantified. The model was developed for evaluating the influence on fouling control of an intermittent aeration of bubbles synchronized or not with the filtration cycles, taking into account the effects of shear intensity on sludge cake removal.

Dynamic multidimensional modelling of submerged membrane bioreactor fouling

“…However, sludge cake is highly compressible [18,24,25] and its properties will vary with time during filtration in a constant flux scenario due to the increase in applied TMP. Therefore, r c for a compressible material can be described by the empirical Eq.…”

“…This model can predict flux, cake thickness, for a given transmembrane pressure and bulk liquid shear, on the basis of parameters such as membrane resistance, solids stickiness and compressibility. Further expansions and modifications to the model have since been made: Wu et al [17] included the effect of variable particle size solids, Zarragoitia-Gonzalez et al [18] integrated the model with the Activated Sludge Model No.1 (ASM1) to predict the impact of biologically produced soluble and insoluble products on membrane fouling and Mannina et al [19] further included deep bed filtration theory to predict COD removal by the accumulated cake layer.…”

The fouling phenomenon in membrane bioreactors: Assessment of different strategies for energy saving

“…MBR models may allow exploring a wide range of operating conditions and comparing different solutions prior to their effective realization/ application. However, studies on a joint simulation of both biological and physical processes for MBR are rare (among others, [16][17][18]) and research on the evaluation of system performance and energy consumption for MBR are at a somewhat elementary state.…”

Sensitivity and uncertainty analysis of an integrated membrane bioreactor model

“…Finally, the integrated models couple hybrid models with physical models and represent the most powerful tool for simulating MBR systems [6,7]. Indeed, the integrated models, taking into account physical and biological processes, provide the right interpretation of MBR systems [4,8]. Recently, Zuthi et al [7] have underlined the importance of using integrated modelling approach to better simulate membrane fouling.…”

“…Thus, by adopting integrated models, the modeller may have the opportunity to improve the performance of her/his predictions by understanding the system in a comprehensive way (considering both biological and physical processes simultaneously). However, although the application of integrated MBR models can represent an useful tool for MBR design and operation, only few integrated models have been developed so far [4,[8][9][10]. Furthermore, the model structure is generally complex and constitutes a critical issue faced by modellers.…”