AWWA ACE58134

An incremental approach has been utilized to develop a fully integrated diffusion based membrane mass transfer model that considers concentration, recovery and osmotic pressure (IMOP) using finite elements. Osmotic pressure is incorporated into the model using correction coefficients that are calculated from boundary conditions as determined by the feed and concentrate stream osmotic pressures. Comparison to other models and verification of the developed model is presented using independently developed water quality and membrane operating conditions from full scale plants as described in the US Environmental Protection Agency (USEPA) Information Collection Rule database and other independently developed pilot scale data. The results and statistical analyses show that the IMOP improves prediction of diffusion controlled permeate water quality significantly. Includes 11 references, tables, figures.