Thermophilic biotrickling filtration of a mixture of isobutyraldehyde and 2‐pentanone

Abstract

In this study, the possibility of the removal of isobutyraldehyde and 2-pentanone was investigated in biotrickling filters (BTFs) at higher temperature (52-65• C). First, the biodegradation of isobutyraldehyde and 2-pentanone in activated sludge was proven by batch experiments at 52 and 62• C. In batch experiments isobutyraldehyde was also degraded up to a temperature of 72• C. Thereafter two bioreactors were operated in parallel, one at ambient temperature (BTF25), and one at 52• C (BTF52). Maximum elimination capacities of 97 and 139 g m −3 h −1 were observed in BTF25 and BTF52, respectively, for isobutyraldehyde. Maximum elimination capacities of 53 and 63 g m −3 h −1 were obtained for 2-pentanone in BTF25 and BTF52, respectively. A significant difference was observed in the operational stability of the two reactors. In the reactor at ambient temperature, operational problems such as foam formation, higher biomass accumulation and organic acid production were observed. In the thermophilic reactor these problems did not occur or were less severe.

Ethylbenzene removal under mesophilic conditions in a biofilter with Macadamia ternifolia nutshells as a carrier material

“…At lower temperatures bacterial growth is known to decrease 25 and also foam formation was visible on the leachate. The decrease in EC at lower temperature could therefore also be influenced by the decrease in bacterial growth and by the foam formation causing clogging in the reactor and limiting the mass transfer of the pollutant through the biofilm, which corresponds to the findings of Luvsanjamba et al 26 Plotting the concentration profiles as a function of the reaction time along the depth of the reactor at an IL of 80 g m −3 h −1 and an EBRT of 90 s for different temperatures, see Fig. 6, resulted in a linear decrease in EB concentration at lower temperatures (292 and 299 K).…”

Biotreatment of Industrial Wastewaters under Transient-State Conditions: Process Stability with Fluctuations of Organic Load, Substrates, Toxicants, and Environmental Parameters

“…Successful applications of thermophilic aerobic treatment processes have been reported despite that results were generally superior in the mesophilic temperature range. 88,115,189,200,214−216 Nevertheless, Luvsanjamba et al 137 obtained better results for thermophilic biotrickling filtration of a waste stream containing isobutyraldehyde and 2-pentone compared to operation at 25 • C. In this study, thermophilic treatment resulted in lower biomass accumulation and foam formation, which resulted in a higher maximum removal capacity.…”

Bioprocesses for air pollution control

“…Under thermophilic conditions, biomass build-up has been observed to be less than under mesophilic conditions. 24,25 The lower overall biomass yields at higher temperatures could result from high maintenance energy requirements or temperature induced growth uncoupling. Besides, biomass distribution along the reactor is often not homogenous, as also mentioned above in the case of conventional biofilters, and significant amounts of non-active microorganisms may be present, which will contribute to increase the pressure drop.…”

“…Thus, the temperature of the filter bed will increase more at higher loading rates. 24,25 Sprinklers are often installed when using natural filter beds in order to maintain optimal conditions with respect to the water content, mainly in open biofilters ( Fig. 3(a)) during the summer period when the top layer of the bed may more easily dry out.…”