Characterize the Process of Denitrification in Contaminated Shallow Groundwater by Hydrocarbon Using GIS System in Nizwa Area, Oman

Hydrocarbon and chemical data from groundwater wells in the Nizwa area of Oman have been compiled and integrated into a GIS system in order to characterize the contamination and the hydrocarbon behavior in groundwater. TPH screening analysis for hydrocarbon shows that all the peaks for the contaminated wells ranging between C15 to C32, which means that the hydrocarbon contamination originated from oil product sources. The absence of low molecular weight hydrocarbons below C12 indicates that the hydrocarbon is old and has been subject to weathering and biodegradation. Denitrification process under anaerobic conditions prevailed in the hydrocarbon contaminated groundwater wells, which resulted in degradation of the hydrocarbon and disappearance of nitrate completely from the contaminated groundwater wells. It is suggested that a bioremediation process involving the addition of groundwater with high nitrate concentration to the contaminated aquifer could be possible under these conditions