Optimizing the Removal and Disinfection of Microorganisms Occluded Within Wastewater Particles

A procedure is presented that provides the basis for optimizing filtration and disinfection systems by assuring that microorganisms occluded in effluent particles are sufficiently inactivated or removed. A secondary effluent sample was collected from an operational treatment facility and used in a series of laboratory tests. Experimental data were then used to calibrate a radial pore diffusion model that considers the mass transfer of an aqueous constituent (chlorine) from the bulk aqueous phase into the interior of spherical porous particles. Following calibration, the model was used to run simulations under a variety of particle size distribution (achieved using filtration) and disinfectant dose scenarios. The final outcome was a matrix of viable effluent particle concentrations for the various filtration and disinfection scenarios. Comparison of the results with acceptable concentrations for effluent viable particles allows for selection of optimal filtration and disinfection operating conditions.