AWWA WQTC52882

The purpose of this study is to evaluate the effectiveness of twobiologically-based preliminary treatment processes (slow sand filtration (SSF)and biologically optimized rapid sand filtration (BORSF)) and one physicalprocess (microfiltration (MF)) for the control of different classes of reverseosmosis(RO)/nanofiltration (NF) foulants in Central Arizona Project (CAP) water.Operation of NF/RO on the effluent from each pretreatment provides a means todetermine the relative contribution of each foulant class to performance impactson the NF/RO membranes. All the NF treatment trains are being operated in aconstant flux, variable feed pressure mode typical of full-scale treatmentplants. Each treatment train is monitored for changes in specific flux, saltpassage, and vessel differential pressure as a function of run time. The feedwaters, the NF permeates, and the concentrates are monitored for water qualityparameters such as turbidity, alkalinity, hardness, disinfection byproducts,total organic carbons, biodegradable organic carbon, cations/anions, particlecounts, coliforms, and heterotrophic plate counts. Includes 2 references, tables, figures.