Removal behavior of gaseous furfural using a biofilter packed with perlite, ripe compost, and oak woodchips

Abstract

Furfural is a toxic compound that is widely used in various industries. Prolonged inhalation exposure to this pollutant, especially at workplaces, can induce detrimental health effects. Therefore it is important to remove it from the environment. The present study aimed to investigate furfural removal from polluted air streams using a biofilter system. In this regard, a 4-section biofilter packed with perlite, ripe compost, and oak woodchips was operated for a 108 day-period under different operating conditions. The effects of pH (natural and acidic), inlet concentration (18.8–81.6 mg m−3), the height of biofilter layers (4 sections), and empty bed residence times (EBRTs) of 120, 70, and 30 s on removal efficiency (RE) of the biofilter were evaluated. All sampling and measurements were performed according to standard methods. The RE values under neutral and acidic conditions were 80 and 65 %, respectively. At furfural inlet concentrations in the ranges of 18.8–21.3, 35.25–42.7, and 78.4–81.6 mg m−3, the RE values were 81, 68, and 57 %, respectively. Also, the RE values at EBRTs of 120, 70, and 30 s were 83, 73, and 61 %, respectively. About half of the total RE was related to the first section of the biofilter, where the number of bacterial (6.2 log10 CFU g-1) and fungal (5.8 log10 CFU g-1) were higher than the other sections. Due to the high RE (72 %) and low pressure drop (below 43 Pa m-1) of the biofilter, it can be concluded that biofiltration is a suitable process to remove furfural from the air.