Development of KOH activated high surface area carbon and its application to drinking water purification Original Research Article

High-surface-area (over 3000 m2 g −1) active carbon (MAXSORB) was developed from a mixture of petroleum coke and an excess amount of potassium hydroxide. A considerable number (0.9–1.6 meq g−1) of surface functional groups were found compared to that of typical steam activated carbons (0.1–0.2 meq g−1). Breakthrough of sodium hypochlorite or chloroform was studied using model drinking water at 25 °C, containing about 2 ppm of NaClO or 50 ppb of CHCl3. Regardless of the amount of surface functional groups, the performance of NaClO decomposition for MAXSORB was proportional to the BET surface area and reached a value of two to three times more than the typical steam activated carbon. There was an optimum BET surface area for CHCl3 removal, which was improved greatly by removing surface functional groups by heat treatment at 700 °C.