id	keyword
american_scientific_journal-1330	biogas
american_scientific_journal-1330	typha
american_scientific_journal-1330	production
american_scientific_journal-1330	volume
american_scientific_journal-1330	domingensis
american_scientific_journal-1330	figure
american_scientific_journal-1330	sciences
american_scientific_journal-1330	biomass
american_scientific_journal-1330	methane