CONTROLS OF HYBRID REACTORS EXHIBITING SUBSTRATE COMPETITION

摘要

This paper develops control strategies over substrate competition in hybrid growth reactors by performing sensitivity analyses of a model to its process parameters. Three sets of indicators, i.e. biomass partitions, substrate partitions, and specific substrate utilization rates, are sued for indicating the competitive responses to the five controllable parameters: empty-bed hydraulic retention time (θ), solids retention time (θ_c), specific surface area of media (Sa), influent substrate concentration (So), and reactor porosity (ε ). Among the five parameters,θc, θ, and Sa should be increased to obtain a low concentration of effluent substrate, where the parameters θ and Sa are more powerful than θc. In contrast, a larger S。makes it more difficult for the operation to achieve better quality of effluent substrate. In addition, parameter ε does not affect the performance. Strategies for promoting individual competitiveness are also proposed to demonstrate how two conflicting sets of parameters ( θ and Sa V.S.θc and S*) can control the reactors. To enhance attached growth, θc and S。should be decreased (and vice versa to enhance suspended growth).