id	keyword
cet-12565	waste
cet-12565	plastic
cet-12565	source
cet-12565	sink
cet-12565	problem
cet-12565	recycling
cet-12565	synthesis
cet-12565	contaminant
cet-12565	engineering
cet-12565	chemical
cet-12565	quality
cet-12565	energy