id	keyword
esrj-84631	water source
esrj-84631	metal pollution
esrj-84631	sources
esrj-84631	pollutants
esrj-84631	tracing
esrj-84631	tourist
esrj-84631	metals
esrj-84631	attractions
esrj-84631	variation
esrj-84631	direction
esrj-84631	metal pollutants
esrj-84631	migration
esrj-84631	pollution source
esrj-84631	diffusion
esrj-84631	coefficient
esrj-84631	concentration