id	keyword
arees-3532	petroleum
arees-3532	water
arees-3532	petroleum hydrocarbons
arees-3532	vol
arees-3532	river
arees-3532	environmental
arees-3532	sediment
arees-3532	journal
arees-3532	oil
arees-3532	nigeria
arees-3532	sample
arees-3532	surface
arees-3532	pollution
arees-3532	contamination
arees-3532	concentration
arees-3532	stations
arees-3532	asian
arees-3532	orashi
arees-3532	work
arees-3532	delta