Influence of the inlet load, EBRT and mineral medium addition on spore emission by Fusarium solani in the fungal biofiltration of hydrophobic VOCs

BACKGROUND: The effect of the inlet n-pentane load (IL), empty bed residence time (EBRT) and mineral medium (MM) addition on spore emission and elimination capacity (EC) was evaluated using the fungus Fusarium solani in a vermiculite-based biofilter. RESULTS: When the process was operated at an EBRT of 3.7 min and an IL of 100 gm ^-3 _reactor h ^-1, the weekly addition of MM from 6.8 to 13.6 mL _MM L ^-1 _vermiculite resulted in fluctuacting dynamics of ECs and spore emission. When varying the n-pentane IL from 25 to 875 gm ^-1 _reactor h ^-1, a maximum EC of 110 gm ^-3 _reactor h ^-1 associated with a spore emission of 1.8 × 10 ⁴ CFU m ^-1 _air was recorded. The critical inlet load for 90% n-pentane removal was 50 g m ^-3 _reactorh ^-1 with spore emission 4.5 × 10 ³ CFU m ^-3 _air Finally, when the EBRT was decreased from 3.7 to 2.1 min at a constant n-pentane IL of 50 g m ^-3 _reactorh ^-1 the EC decreased by 110%. CONCLUSIONS: The results show a poor performance of the n-pentane biofiltration system at high IL and low EBRT, which was further confirmed by the low final biomass concentrations in the biofilter (62 mg _biomass g _biomass g ^-1 _vermiculite).