Effect of oil concentration and residence time on the biodegradation of α-pinene vapours in two-liquid phase suspended-growth bioreactors

Abstract

Recently, research on the use of binary aqueous-organic liquid phase systems for the treatment of polluted air has significantly increased. This paper reports the removal of α-pinene from a waste air stream in a continuous stirred tank bioreactor (CSTB), using either a single-liquid aqueous phase or a mixed aqueous-organic liquid phase. The influence of gas flow rate, load and pollutant concentration was evaluated as well as the effect of the organic to aqueous phase ratio. Continuous experiments were carried out at different inlet α-pinene concentrations, ranging between 0.03 and 25.1 g m⁻³ and at four different flow rates, corresponding to residence times (RTs) of 120 s, 60 s, 36 s and 26 s. The maximum elimination capacities (ECs) reached in the CSTB were 382 g m⁻³ h⁻¹ (without silicone oil) and 608 g m⁻³ h⁻¹ (with 5%v/v silicone oil), corresponding to a 1.6-fold improvement using an aqueous-organic liquid phase. During shock-loads experiments, the performance and stability of the CSTB were enhanced with 5% silicone oil, quickly recovering almost 100% removal efficiency (RE), when pre-shock conditions were restored. The addition of silicone oil acted as a buffer for high α-pinene loads, showing a more stable behaviour in the case of two-liquid-phase systems.

Influence of polymeric materials on the performance of a mesophilic biotrickling filter treating an α‐pinene contaminated gas stream

“…Gas‐phase concentrations of α‐pinene and CO 2 were analyzed using the analytical procedure and equipment reported previously . At different time intervals, packing samples were removed from the BTF.…”

“…α‐Pinene was selected in this work as model compound because of its hydrophobicity, its complex degradation and past experience in our group . Because the low solubility of α‐pinene appears to contribute to its poor removal as a result of mass transfer limitation, polymer beads were added to the packing material, which would presumably improve α‐pinene removal.…”

Biofilter treatment of gas phase β-caryophyllene at an elevated temperature

“…Air quality is affected by the terpenes both in air and photochemical oxidants, and tropospheric ozone formed in reactions involving terpenes (Granstrom, 2009;Montes et al, 2012). Photochemical oxidants such as hydrogen peroxide, organic peroxide, organic nitrate, and reactive organic aerosols in the presence of nitrogen oxides (NOx) disturb the photosynthesis of plants causing forest and crop damage, and at sufficiently high concentrations are harmful to humans causing respiratory difficulties and mucous membrane irritation (Bagherpour et al, 2005;Beakler et al, 2007;Granstrom, 2009;Montes et al, 2012;.…”

“…As a sesquiterpenes, β-caryophyllene has the same characteristic with terpene (Li et al, 2011). Thus, it contributes to the depletion of ozone, breaking the natural cycle of NOx and catalyzing the reaction of smog formation (Bagherpour et al, 2005;Montes et al, 2012). The emission of β-caryophyllene can have adverse effects on both human health and the environment, causing respiratory irritation problems and disturbing the photosynthesis of plants (Beakler et al, 2007;Granstrom, 2009).…”

Enhancing Chlorobenzene Biodegradation by Delftia tsuruhatensis Using a Water-Silicone Oil Biphasic System

“…The presence of NAPs can improve mass transfer of hydrophobic VOCs. Moreover, NAPs can absorb excess VOCs and deliver them at subinhibitory levels to microorganisms suspended in the aqueous phase [12,24]. Microbial activity, which is critical to biodegradation, could directly reflect the effect of NAP on substrate inhibition alleviation.…”