Modeling of bioactive carbon adsorbers: A hybrid weighted residual-finite difference numerical technique

Phenomenological mathematical models incorporating adsorption, mass transfer, and biofilm degradation were developed for performance prediction/simulation of bioactive carbon fixed-bed and fluidized-bed adsorbers in wastewater treatment. The model equations were solved by a numerical technique combining a weighted residual technique such as orthogonal collocation with finite difference method. This hybrid technique was numerically consistent and stable and provided accurate solutions at computing times lower than those corresponding to pure orthogonal collocation. The bioadsorber model parameters were independently determined from carefully designed laboratory-scale experiments and correlations. The model predictions of bioadsorber effluent concentration profiles were in strong agreement with the experimental data, illustrating the good predictive capability of the model. Sensitivity studies were performed to identify the influence of model parameters on the bioactive adsorber dynamics.