Effects of n-butanol presence, inlet loading, empty bed residence time and starvation periods on the performance of a biotrickling filter removing cyclohexane vapors from air

Abstract

This paper presents the results of investigations on the removal of cyclohexane vapors from air using a peat-perlite packed biotrickling filter. Effects of basic process parameters i.e. inlet loading and empty bed residence time as well as introduction of n-butanol to the treated air stream and starvation periods on the process performance were evaluated. The results show that the introduction of hydrophilic n-butanol results in an enhanced removal of hydrophobic cyclohexane comparing to the experiments where only cyclohexane was treated. Additionally, the biotrickling filter performance after the starvation events is regained to more extent for mixed system than for the single cyclohexane. A novel and interesting element of the paper is the application of an electronic nose for the process monitoring. Obtained results are discussed in the perspective of an influence of the presence of a compound with different affinity to aqueous phase on the removal efficiency of the compound with opposite chemical properties. Keywords Biofiltration • Biotrickling filter • Cyclohexane • n-Butanol • Removal of VOCs • Electronic nose List of symbols a Coefficient of MLR model B Boiling point (°C) BF Biotrickling filter BTF Biotrickling filtration c Concentration of cyclohexane in the gas mixture (ppm v/v) C Concentration of cyclohexane in the gas mixture (mg m −3) d Internal diameter of BTF (m) EC Elimination capacity (g m −3 h −1) EBRT Empty bed residence time s GC Gas chromatography h Total height of a BTF packing (m) H Henry's constant (mol m −3 Pa −1)

Simultaneous Removal of Hexane and Ethanol from Air in a Biotrickling Filter—Process Performance and Monitoring Using Electronic Nose

“…The peat and perlite packing was used without special inoculation, taking advantage of the naturally present diversified microflora. A more detailed description of the experimental set-up is provided in [26].…”

“…The mixture of air with hexane (Merck, Darmstadt, Germany) and ethanol (POCH, Gliwice, Poland) was obtained using an automatic gas mixture generator as described previously [26]. The gas flow rate was controlled using a precise mass flow controller (Vögtlin, Aesch, Switzerland).…”

“…Concentrations of the individual components of the mixture (ethanol and hexane) were determined based on the multiple linear regression (MLR) models. Development of the MLR models was as described in our previous works [26,40].…”

“…First, the process mechanism of the biofiltration of compounds with different hydrophobicity is not fully understood, revealing a considerably lower number of scientific papers discussing the biotrickling filtration of gas mixtures compared to the results of treating air polluted with a single component [23]. Second, real gas mixtures contain components with different chemical properties (affinity to aqueous phase, among others), thus resulting in a varied elimination capacity, depending on the types of compounds present in a gas stream [24][25][26][27][28][29].…”

“…In this paper, two methods were applied for the process performance monitoring (i.e., gas chromatography and electronic nose). The selection of an electronic nose is based on its ability for continuous process monitoring as well as its proven application in the assessment of the biofiltration efficiency of air deodorization [23,26,36,37].…”