Granular activated carbon usage in chloramine removal from dialysis water

Chloramines, oxidant compounds used in municipal drinking water as sanitizing agents, potentiate hemolytic anemia when present in dialysate. Thus far, the addition of ascorbic acid to the dialysate and the use of granular activated carbon (GAC) have been the only reliable, practical methods reported for removing chloramines. This is a report on the bench-scale testing of five kinds of GAC from three manufacturers. The performance of 100 g of each carbon was studied in a 2-in-diameter column through which feed-water containing approximately 1.5 mg/L chloramines flowed downward at an average volumetric rate of 140 ml/min. The carbons' experimental capacities for chloramines differed by as much as one order of magnitude. The experimental results were used to estimate the capacity of a 9-in-diameter, 45-in-tall column of the best carbon. These scale-up estimations indicate that this sorbent may safely last through 156 5-h dialyses.