Formation and Removal of Volatile Organics in Surface Water Treatment

A four month study was carried out at the Buffalo Pound Water Treatment Plant near Regina, Saskatchewan to examine the formation and removal of volatile organic compounds. Nine volatile organics were found to be consistently formed or added to the water during full scale conventional treatment. Only the chlorine-containing trihalomethanes were present at levels greater than 1 ug/L. Removal of these compounds was investigated in pilot scale granular activated carbon post contactors; the study examined both fresh carbon and carbon which had been used in a previous four month investigation. All compounds were removed to some degree on the carbon. The location of removal within the columns varied with the different compounds and the results suggested formation of some compounds within the columns. Post chlorination of column effluent resulted in at most a modest increase in the concentrations of the organic compounds.