TITLE:
Role of Fungal Biomass in N-Hexane Biofiltration
AUTHORS:
Mena M. Botros, Ashraf Aly Hassan, George A. Sorial
KEYWORDS:
Biofiltration, N-Hexane, Trickle Bed Air Biofilter (TBAB), VOCs, Fungi
JOURNAL NAME:
Advances in Microbiology,
Vol.7 No.10,
October
16,
2017
ABSTRACT:
The biofiltration of n-hexane is studied to optimize determinants factors of
hydrophobic VOC filtration efficiency. Four trickle-bed air biofilters (TBABs)
were employed; two of which were supplied with nutrients buffered at a neutral
pH, while another two at an acidic pH of 4 to induce and enhance fungal
growth. The loading rate of n-hexane was kept constant in all TBABs at 13
g/m3/h. At each pH levels studied, the biomass of the TBABs was pre-acclimated
using different ratios of n-hexane and methanol. The fungal biomass responsible
for the degradation of n-hexane was then examined and quantified.
Dichloran Rose Bengal Chloramphenicol agar was used for fungi quantification,
and optical microscopy for classification. Effluent biomass was validated
by measuring volatile suspended solids. Fungal counts resulting from n-hexane
biodegradation were related to nitrate and carbon consumption. It was found
that n-hexane elimination capacity closely followed biomass growth, and
reached a steady-state at an optimum biomass density of roughly 3000 cfu/ml.
Major shifts in fungal species were observed in all TBABs. Dominant fungal
species grew slowly to become the most numerous, and were found to provide
maximum elimination capacity, although TBABs pre-acclimated to higher
methanol concentrations took less time to reach this steady-state. It was concluded,
therefore, that steady and monitored growth of TBAB biomass is an
essential factor in maximizing fungi’s ability to metabolize VOCs and that a
new ecological biofiltration model may be the most effective at VOC purification.
Keywords