AWWA JAW37633

Costs of several ultrafiltration and nanofiltration processes are compared with the cost of conventional liquid-solid seperation with and without GAC adsorption for small facilities. Data on raw-water quality, permeate flux, recovery, frequency of backflushing, and chemical dosage obtained from a pilot study were used with a previously developed model for membrane costs to calculate anticipated capital and operating costs for each instance. Data from the US Environmental Protection Agency were used to estimate conventional treatment costs. All of the membrane process calculations showed comparable or lower total costs per unit volume treated compared with the conventional treatment for small facilities (<200,000 m3/d or about 5 mgd). Includes 10 references, tables, figures.