Steady-State Performance of an Activated Carbon Biofilter Degrading Styrene: Effects of Residence Time and Inlet Concentration

Abstract

A granular-activated-carbon-packed biofilter receiving a constant loading rate of styrene was subjected to changes in residence time and concentration, and the effects on performance characteristics and the composition of biofilm along the bed height in the biofilter were studied. This study was carried out during the last 3 months of the entire biofilter operation of 16 months. The total bed height of the biofilter was physically divided into four individual reactor stages in series. This configuration permitted measurement of the leachate pH in each stage. Also, between-stage mixing of the culture was minimized. Each reactor stage was loaded in an upflow mode. The shortest residence time tested, 1.05 min, resulted in a decrease of removal efficiency to 95% (from 100% achieved at longer residence times). The shorter residence time nonetheless resulted in a higher elimination capacity in the higher stages of the filter bed. In the first two stages, the leachate pH values were 6.4 and 6.6, slightly lower than in higher stages (pH 7). A decrease of the styrene concentration along the bed height significantly affected the total cell number of immobilized cells whereas the number of degraders, Pseudomonads, and eukaryotes changed only a little. Microbial analysis of the mixed culture showed the presence of four bacterial strains and three fungi.

Biofiltration of gasoline and diesel aliphatic hydrocarbons

“…This phenomenon was observed despite the fact that the first stage accounted for the majority of the biofilter elimination capacity and was particularly pronounced with gasoline as a substrate (Figures 6a and 6b). This pattern seems to contradict our earlier observations obtained with other hydrocarbon mixtures (Paca et al, 2009a;Paca et al, 2009b), as well as the common paradigm that the pH drop increases along with the biodegradation rate, that is, is greater in the first stage. Also, CO 2 releasing during biodegradation can cause some drop of pH.…”

“…As we observed previously, Pseudomonas bacteria are widespread in biofilm reactors for wastewater treatment and are able to degrade a wide range of aromatic and aliphatic hydrocarbons (Paca et al, 2007;Paca et al, 2009a;Paca et al, 2009b;Paca et al, 2010). Other authors also reported a versatile and diverse hydrocarbon degrading activity of Pseudomonas bacteria (Song et al, 2006;Duarte da Cunha and Leite, 2000;Das and Chandran, 2011).…”

“…Other authors also reported a versatile and diverse hydrocarbon degrading activity of Pseudomonas bacteria (Song et al, 2006;Duarte da Cunha and Leite, 2000;Das and Chandran, 2011). Chryseobacterium indologenes bacteria are (1.1 ± 0.2) × 10 6 also commonly observed in biofiltration (Paca et al, 2007;Paca et al, 2009a;Paca et al, 2009b;Paca et al, 2010), but usually with a lower degradation potential in comparison to Pseudomonas. Among the other bacteria, Acinetobacter sp.…”

The impact of Ivan Málek’s continuous culture concept on bioprocessing

“…Other designs were also proposed, e.g., a pilot multistage tower fermenter [74,84]. A design for venting bioWlters has also been proposed [76,77].…”

Effect of loading types on performance characteristics of a trickle-bed bioreactor and biofilter during styrene/acetone vapor biofiltration

“…Strains of these genera are frequently described as efficient VOC degraders. [3,11,28,29] All recovered fungal species, Aspergillus sp., Cephalosporium sp., Cladosporium sp., Penicillium sp., were also primary degraders of both substrates as consistent with literature where they are described as versatile degraders of a wide range of VOCs. [3,28,30,31] Flies as a means of the biomass control in the BF In addition to microorganisms, flies were found in the biofilter (Fig.…”