AWWA ACE61769

The objective of this study was to evaluate the effect of pH on the release of arsenic for a select group of drinking water distribution system (DWDS) solids and full scale treatment column media. X-ray diffraction (XRD) and ICP-AES analysis were conducted to provide a comprehensive characterization of the solids. Aliquots of each solid and column media were added to deionized water (DIC = 10 mg C/L for background alkalinity) at pH 7, 8, and 9 for 168 hours. The supernatant was extracted and analyzed by GFAA and ICP-AES for total arsenic and additional elemental concentrations, such as iron, aluminum and calcium. This study concluded that arsenic desorbs from DWDS solids and full scale treatment column media. Also the amount of arsenic desorbed from the DWDS solids also increased as pH of the water increased. Includes 8 references, tables, figures.