Adsorption/reduction of bromate from drinking water using GAC: Effects on carbon characteristics and long-term pilot study

Abstract

This study investigated the feasibility of using granular activated carbon (GAC) to remove bromate (BrO3-) from drinking water through batch experiments, rapid small-scale column tests (RSSCT) and a pilot-scale study. The results indicated that the GAC capacity for BrO3-removal was dependent on the GAC surface characteristics and empty-bed contact time (EBCT). The GAC with a high number of basic groups and higher pH pzc values showed an increased BrO 3-removal capacity. On the other hand, BrO 3removal was improved by increasing EBCT. In the GAC pilot plant, a GAC column (operating with 15 min EBCT) preload for 12 months achieved a BrO3-and assimilable organic carbon (AOC) removal rate ranging between 7 and 96 % and between 41 and 85 %, respectively. The amount of BrO3-removed was found to be proportional to the influent BrO3-concentration. Based on the results of our long-term experiment, the BrO3-and AOC removal rate during the transition from initial GAC to biological activated carbon (BAC) was calculated as 0.12 % w/w and 0.27 % w/w, respectively.

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