http://www.vocabularyserver.com/gemet/en/http://www.vocabularyserver.com/gemet/en/xml.php?skosTema=878biological waste gas purification http://www.vocabularyserver.com/gemet/en/xml.php?skosTema=878 biofiltration RT http://www.vocabularyserver.com/gemet/en/xml.php?skosTema=878 waste air purification (gas) BT