Procédé et système de traitement biologique pour bioprocédés continus susceptibles de présenter une inhibition

brevet paru le 9/08/2013 (Bulletin Officiel de la Propriété Industrielle n° 32) hal-01095712The method comprises, given a value of a volume of reference (V) of a reactor supplied with a constant flow (Q), dividing the volume into a first digester of a first volume (V1) and a second digester of a second volume (V2) such that a sum of the first volume and the second volume is equal to that the volume of reference, inoculating the second digester by a microbial ecosystem to convert a part of a substrate and to present an inhibition of growth by the substrate in an initialization phase, dividing the flow into a first flow and a second flow such that the first flow supplies exclusively the first digester, and the second flow supplies initially second digester before being redistributed in the first digester. The method further comprises predetermining a target value of concentration in the substrate, in which the first volume (V1=rV) is a percentage volume of reference with r as a parameter, the second volume (V2=(1-r)V) is percentage complementary to the volume of reference, the second flow (Q2=alpha Q) is a percentage of the rate of constant flow with alpha as a parameter, and the first flow (Q1= (1-alpha )Q) is complementary percentage to the rate of constant flow; determining a dilution ratio of the second volume of the second digester and the dilution rate to be less than the value of the curve growth of the data on the microbial ecosystem for the given substrate; deducing a concentration value in the substrate corresponding to that of the dilution ratio from the growth curve; determining a set of values according to the value of the dilution rate and the value of the dilution ratio; choosing a subset of values from the determined set of values; determining a function representative of a speed or specific contribution in the substrate in the first digester at a given concentration based on a value of the parameter; selecting a value from the chosen values such that a variation curve of the function meets a graph of the function at more than one point; selecting a value from the chosen values such that the variation curve of the function does not meet a graph of the function at more than one point as the single point corresponds to a value of concentration in the weakest possible substrate; comparing the output concentration with the target value; and modifying the value of the parameter and/or the dilution ratio according to the result of the comparison. The volume of reference is equal to the rate of constant flow divided by a dilution rate, where the dilution rate is equal to a value of curve growth on microbial ecosystem data for the given substrate at a predetermined target value. An independent claim is included for an effluent treatment system.L'invention concerne un bioprocédé continu de traitement d'un effluent à débit d'alimentation (Q) constant et comprenant un substrat à une concentration d'entrée (Sin) et de sortie (S**) ; comprenant des étapes consistant à : - déterminer un volume de référence (V) d'un réacteur alimenté par le débit (Q), - scinder le volume (V) en un premier digesteur de premier volume (V1) et un deuxième digesteur de deuxième volume (V2), tels que le premier volume (V1) plus deuxième volume (V2) égalent ledit volume (V), - ensemencer préalablement au moins le deuxième digesteur par un écosystème microbien susceptible de convertir ledit substrat et de présenter une inhibition de croissance ; - distribuer ledit débit (Q) en : o un premier débit (Q1) alimentant exclusivement le premier digesteur et un deuxième débit (Q2) alimentant d'abord le deuxième digesteur avant le premier digesteur

Design, Analysis and Validation of a Simple Dynamic Model of a Submerged Membrane Bioreactor

International audienceIn this study, a simple dynamic model of a submerged Membrane BioReactor (sMBR) is proposed, which would be suitable for process control. The system dynamics is first analyzed showing the existence of three different time scales. The existence of slow-fast dynamics is central to the development of a dedicated parameter estimation procedure. The proposed model structure is validated using realistic simulation data from a detailed simulator built in a well-established environment, namely GPS-X. Finally, a nonlinear model predictive control is designed to illustrate the potential of the developed model within a model-based control structure. The problem of water treatment in a recirculating aquaculture system is considered as an application example

Integrated membrane bioreactors modelling: A review on new comprehensive modelling framework

Integrated Membrane Bioreactor (MBR) models, combination of biological and physical models, have been representing powerful tools for the accomplishment of high environmental sustainability. This paper, produced by the International Water Association (IWA) Task Group on Membrane Modelling and Control, reviews the state-of-the-art, identifying gaps for future researches, and proposes a new integrated MBR modelling framework. In particular, the framework aims to guide researchers and managers in pursuing good performances of MBRs in terms of effluent quality, operating costs (such as membrane fouling, energy consumption due to aeration) and mitigation of greenhouse gas emissions

A generic and systematic procedure to derive a simplified model from the anaerobic digestion model No. 1 (ADM1)

International audienceThe anaerobic digestion model No.1 (ADM1) developed by the IWA Task Group for mathematical modellingof anaerobic digestion processes Batstone et al. [1] is a structural model which describes the mainbiochemical and physicochemical processes. For such purposes, other models have been proposed todescribe anaerobic processes with a reduced set of parameters, state variables and processes. Amongthem, the anaerobic model No. 2 (AM2) proposed by Bernard et al. [2] which describes the degradationof soluble organic compounds, appears as a model well-suited for control and optimization applications.In this work, we aimed at obtaining a model of reduced dimensions on the basis of which to synthesizeregulators or observers with guarantees of performance, stability and robustness. Specifically, our contributionis twofold. First, a modified version of the AM2 is proposed while preserving the simplicity ofthe new model “AM2HN”. Second, we propose a systematic and generic state association procedure inorder to obtain such a simplified model from any validated ADM1.Simulations and comparisons with the predictions of theADM1for a case study involving the anaerobicdigestion of waste sludge are presented along with satisfactory results

A new hypothesis to explain the coexistence of n species in the presence of a single resource

This paper presents a hypothesis allowing us to explain the coexistence of several species (here micro-organisms) in competition on a single resource (called a substrate) in a chemostat. We introduce a new class of kinetics that does not only depend on the substrate concentration in the medium, but also on the biomass concentration. From the study of elementary interactions (i) between micro-organisms, (h) between micro-organisms and their environment in which they grow and from simulations, we show that this modelling approach can be interpreted in terms of substrate diffusion phenomena. A rigorous study of this new class of models allows us to hypothesize that abiotic parameters can explain the fact that an arbitrarily large number of species can coexist in the presence of a unique substrate

Stabilization of a Periodic Trajectory for a Chemostat with Two Species

 We study a chemostat model with two organisms using Lyapunov function methods. Using a linear feedback control of the dilution rate and an appropriate time-varying substrate input concentration, we produce a locally exponentially stable oscillatory behavior for the species concentrations, meaning all trajectories of the chemostat that stay near the oscillatory reference trajectory are actually attracted to the reference trajectory exponentially fast. We also obtain a globally stable oscillatory reference trajectory for the species concentrations, using a nonlinear feedback control depending on the dilution rate and the substrate input concentration. This guarantees that all trajectories for the closed loop chemostat dynamics are attracted to the reference trajectory. We demonstrate the efficacy of our method using a numerical simulation

Output tracking of bioprocesses through recirculation with unknown input concentration

International audienceIn a recent work, a new regulator of the output of a continuous autocatalytic bioprocess, by means of recirculation loop, has been presented. It was shown that controlling the recirculation flow rate allows the stabilization of the output in presence of an uncontrolled input flow rate. In the present paper, we extend this result when the input substrate concentration is unknown. For this purpose, we propose the design of an observer of the input concentration which, coupled with a slightly different control law reminiscent of the one used in the case where the input concentration is known, guarantees the regulation of the output

Output tracking of continuous bioreactors through recirculation and by-pass

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Design of continuous bioprocesses and biodiversity

We revisit the design problem of series of bioreactors, when more than one species is in competition for a single resource. We give precise conditions under which coexistence of two species is possible for such configurations. Furthermore, we show that for a broad class of growth functions, the optimal design cannot sustain coexistence of more than one species (either a new species is rejected or it invades the whole system)

Analyse mathématiques de modèles de digestion anaérobie avec phase d'hydrolyse

International audienc