AWWA JAW28821

The primary objectives of this study were to optimize granular activated carbon (GAC) treatment to meet more stringent trihalomethane (THM) standards, to estimate the costs of optimized GAC treatment, to identify by-products of the final disinfection of GAC-treated water, and to assess the ability of the rapid small-scale column test (RSSCT) to simulate total organic carbon (TOC) breakthrough from pilot-scale carbon contractors. The lowest THM concentration achievable by means of GAC treatment was found to be 10 ug/L. It was concluded that this type of treatment is expensive for the control of THMs, the predominant by-products of postdisinfection of GAC effluents with chlorine or chloramines. The RSSCT was shown to be an economical means of estimating pilot-scale TOC breakthrough, which can be used in making preliminary estimates of carbon utilization rates and cost estimates. Includes 14 references, tables, figures.