WRRCSR No.09:24:92 Granular Activated Carbon Treatment of Mililani Well Water: Phase II Study to Extend Effective Life of GAC, Six-Month Progress Report

Abstract

The aerated Mililani well water, which removed about 40% of TCP, and spiked deionized water, intended to reduce the level of natural background organics, both appeared to increase the volume of water passing through the minicolumns before breakthrough by nearly 40%. Likewise the carbon usage rates for the spiked deionized water and aerated Mililani well water decreased in comparison to untreated Mililani well water, except for the March 1992 minicolumn experiment, which was nearly the same. More minicolumn tests will need to be performed to ascertain if the March 1992 minicolumn results were reasonable or, possibly an anomaly. The minimum minicolumn carbon usage values of approximately 0.022 lb/1000 gal did not simulate field operation values which ranged from 0.135 to 0.150 lb/1000 gal; however a close correlation would not be expected. In addition, the aerated Mililani well water samples did not increase the weight of TCP and DBCP that was able to be adsorbed by the pulverized GAC. Thus, it seems apparent that background material (presumably organic or primarily organic material) may be utilizing adsorption sites. No apparent relationship existed for TC or NPOC removal before and after breakthrough. Further minicolumn experiments will be continued to substantiate the minicolumn experimental data collected to date.