AWWA WQTC62512

The objective of this study was to develop credible design/operation criteria for granularactivated carbon (GAC), magnetized ion exchange (MIEX®) resin, and fixed-bed ion exchange(IX) processes that enabled the Palmdale Water District Water Treatment Plant, CA (PDWTP)to limit total trihalomethanes (TTHMs) and haloacetic acids (total of five species, HAA5)formation up to 60 g/L and 45 g/L, respectively. The process selection conducted by thePWDTP was based on these design criteria and associated cost-analysis evaluation.A six months pilot-scale study was conducted at the PDWTP, during which the differenttreatment processes were tested at pilot-scale. A total of 90 SDS tests were performed. Allprocesses successfully reduced SDS-TTHH and SDS-HAA5 below the stipulated goals.Combining MIEX® treatment operating with a 5% RR and 15% RR, respectively with 50 and 28mg/L of ferric chloride, decreased SDS-TTHMs to 47 and 52 g/L. The bromide-specific resinsuccessfully reduced SDS-TTHMs to values below 47 g/L, while the NOM-specific resinaveraged SDS-TTHMs around 46-73 g/L, up to a maximum of 100 g/L. After 120 days ofoperation GAC effluent SDS-HAA5 were <20 g/L. SDS-TTHM concentrations were maintainedbelow 60 g/L up to 60 days and never exceeded 80 g/L. Using a model that assumed theblending of 10 GAC adsorbers' effluents resulted in a average concentration of 60 g/L after120 days in operation. DBP formation was predicted using a DWR model. Includes 2 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2005

Number of Pages:

18

File Size:

1 file , 590 KB