Abstract
A novel medium consisting of iron oxide-coated porous ceramsite (modified ceramsite) was investigated for NO removal under thermophilic conditions in this study. We used a surface coating method with FeCl3·6H2O as the modifier. When ceramsite was calcined for 4 h at 500 °C, the surface pH value decreased to 3.46, which is much lower than the isoelectric point of ceramsite, ensuring its surface was electropositive. The surface of modified ceramsite changed from two- to three-dimensional and exhibited excellent adsorption behavior to assist microbial growth; the maximum dry weight of the biofilm was 1.28 mg/g. It only took 8 days for the biofilter constructed from the modified ceramsite to start up, whereas that packed with commercial ceramsite took 22 days. The NO removal efficiency of the biofilter did not decrease apparently at high NO inlet concentration of above 1600 mg/m3 and maintained an average value of above 90% during the whole operation period. Additionally, the morphological observation showed that the loss of the surface coating was not obvious, and the coating properties remained stable during long-term operation. The maximum NO inlet loading of the biotrickling filter was 80 g/(m3·h) with an average removal efficiency of 91.1% along with a quick start-up when using the modified ceramsite filler. Thus, modified ceramsite can be considered a very effective medium in biotrickling filters for NO removal.
Highlights
With the rapid industrial development achieved in recent years, the emission of flue gas has increased, which is strongly linked to air pollution levels
Ceramsite modification greatly shortened the start-up period. These results indicated that the biofilter packed with the modified filler could be quickly started up by inoculation with C. daeguensis TAD1
The ironresults oxide-modified a filter medium a biotrickling process was interconnected crystal structure, which was more suited to microbial growth than the compact and investigated
Summary
With the rapid industrial development achieved in recent years, the emission of flue gas has increased, which is strongly linked to air pollution levels. Nitrogen oxides (NOx ) from flue gas can cause acid rain and are the main substance during the formation process of photochemical smog. NOx can destroy the ozone, which brings a threat to human health and the environment [2]. For a long period of time, chemical and physical methods are the basis for the purification treatment of NOx [3]. The typic techniques of simultaneous desulfurization and denitrification are widely used in atmospheric control [4], while being prohibitively expensive when dealing with large volumes of flue gas [5]. Secondary pollutants can be produced and often need further treatment [6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
