Formaldehyde Removal From Airstreams Using a Biofilter With a Mixture of Compost and Woodchips Medium Publisher



Rezaei M¹ ; Fazlzadehdavil M² ; Hajizadeh Y¹
Source: Water, Air, and Soil Pollution Published:2014

Abstract

The performance of a laboratory-scale biofilter packed with a mixture of compost and woodchip on formaldehyde removal from polluted air streams was investigated. The reactor was inoculated with aerobic sludge as a source of bacteria, obtained from a municipal wastewater treatment plant. A nutrient solution was daily added to the reactor media. An airflow containing different concentrations of formaldehyde (from 20±2 to 276±5 mg m-3) was introduced into the reactor. In inlet formaldehyde concentration, an average removal efficiency and elimination capacity of 91 % and 0.36 g m-3 h-1 were attained, respectively, at180 s empty bed residence time (EBRT). After acclimatization of the system for increased formaldehyde concentrations of up to 276±5 mg m-3 and for EBRT of 180 s, those values were stabilized at around 72 % and 3.98g-3 h-1, respectively. The experimental results showed that the system was effective for a high loading rate of formaldehyde with an acceptable EBRT. Compared to the application of compost alone as a media, a mixture of compost and woodchip (50/50 v/v%) enhanced the performance of the biofilter. The most predominant microorganism involved in the biodegradation of formaldehyde was a species of citrobacter called Citrobacter freundii, an aerobic gram-negative bacillus. Pressure drop of the reactor over the entire operations was about 1 mmH2Om-1. © Springer International Publishing 2014.