Activated carbon and residual nitrification for higher quality effluents for the coastal areas

Efforts for the task of modification of a nitrification/denitrification unit operating in a series of two fixed bed columns are outlined. The problem was elevated dissolved oxygen concentrations at the entrance of the denitrification column, resulting in an excessive consumption of methanol. The possibility of using a column of activated carbon for adsorption alone and in which both adsorption and residual nitrification take place was investigated. The results were observed to be very satisfactory in reducing dissolved oxygen levels to practically zero at the entrance of the denitrification unit especially for the case where both adsorption and residual nitrification were employed.