Distillery fusel oil as an alternative carbon source for denitrification – from laboratory experiments to full-scale applications

Abstract

Industrial waste products may be a viable alternative to commercial external carbon sources. In this study, the properties of fusel oil (distillery waste product) were investigated in terms of temperature dependency of denitrification and acclimation period. Furthermore, results obtained during three different full-scale trials were used to verify similarities with and differences from the results obtained under laboratory-scale conditions. Batch experiments with non-acclimated biomass revealed a very strong temperature dependency of the denitrification process (θ = 1.15, R(2) = 0.92) in the range of examined process temperatures (13-22 °C). Fusel oil had minor (or no) effects on the behaviour of NO2-N and PO4-P. Significantly lower nitrate utilization rates were observed during acclimation to fusel oil in the full-scale bioreactors compared to a bench-scale reactor. This may primarily be attributed to lower doses of fusel oil, lower process temperatures and more complicated process configurations (resulting in non-optimal use of fusel oil for denitrification). Results obtained from both laboratory-scale experiments and full-scale trials suggested that an acclimation period of a few weeks would be required to reach the maximum denitrification capability of process biomass, even though positive effects of dosing can be observed almost immediately.

Denitrification Process Enhancement and Diversity of the Denitrifying Community in the Full Scale Activated Sludge System after Adaptation to Fusel Oil

“…The initial NURs for the non-adapted activated sludge from the Poznan WWTP were comparable to the NUR values measured in our previous lab scale studies, also for not The initial NURs for the non-adapted activated sludge from the Poznan WWTP were comparable to the NUR values measured in our previous lab scale studies, also for not acclimated biomass to an external carbon source [20]. After adaptation to fusel oil, the NUR obtained in this study (2.7 mg NO 3 -N/g VSS•h) was significantly lower in relation to the values obtained in lab-scale experiments, where the NUR was as high as 16.0 mg NO 3 -N/g VSS•h [20,22].…”

“…1,700,000 g O 2 /m 3 ) and a favorable COD/TN ratio (approximately 1800). It was found that 2-methyl-1-butanol was a dominant component of fusel oil (almost 40% by weight), with three other important components: 2-methyl-1-propanol, 3-methyl-1-butanol and ethanol [22].…”

“…Another issue that has to be taken into account is the potential toxicity of the applied substrate. In our previous studies [22], detailed analyses of the composition of ten fusel oil samples were performed. The scope of the analyses included 29 selected organic compounds, as the study was also aimed at their potential toxicity.…”

“…In previous studies related to the use of fusel oil to increase the denitrification process rate, most experiments were conducted in lab-scale and their impact on the microbial communities was assessed during relatively short time perspectives [19,20]. For full scale investigations, no analysis of microbial data was provided [21,22].…”

The metabolic activity of denitrifying microorganisms accumulating polyphosphate in response to addition of fusel oil

“…The aim of this study was to investigate changes in the metabolic activity of the DPAOs under anaerobic/anoxic conditions in response to addition of a distillery waste product (fusel oil). This compound is potentially a very favorable carbon source for denitrification due to the advantageous composition, i.e., high chemical oxygen demand (COD) concentrations and high COD/N ratios, which has been confirmed in a few earlier studies [ 20 , 21 ]. However, the anoxic interactions between denitrification and EBPR in the presence of fusel oil have not been reported so far.…”