RJEEC, Volume 3, no. 2, 2021

This study is moving forward with some available options for upgrading the biotrickling filters (BTFs) treating volatile organic compounds (VOCs) in air, in the light of lowering their greenhouse gas (GHG) emissions. One of such options refers to the addition of the microalgae component to the biological matrix involved in such systems, by (co)immobilization, for the capture of the carbon dioxide issued from the VOCs biodegradation and potentially contributing to the overall VOCs removal performance. Particularly, alginate beads with (co) immobilized microorganisms (microorganisms isolated from commercial compost and microalgae Arthrospira platensis PCC 8005) are for the first time tested for this purpose, as follows: beads with entrapped compost-based microorganisms and attached microalgae (BTF-I); beads with an entrapped mixture of microalgae and compost-based microorganisms (BTF-II). Although both options provided promising performances in treating air contaminated with ethanol (as a model VOC in this study), the last option exhibited lower CO2 emissions and higher packing bed durability, being more prone to further development and implementation.