Treatment of Styrene-Contaminated Air Using Combined Process of Microelectrolysis and Biotrickling Filter

Treatment of styrene-contaminated air using a combined process of microelectrolysis and biotrickling filter was studied in this article for the first time. Removal of styrene was higher than 95% and kept rather stable after the process reached a stable state. The active substance produced by microelectrolysis with an appropriate electric current presenting the synergy effect for the combined process, resulted in an improvement in the styrene removal. There exists an optimum electric current for the combined process. At the residence time (RT) of 108 s and the styrene inlet load of 15 g/(m3·h), when the electric current increased from 50 to 150 mA, styrene removal increased from 92.6–94.4% to 98.5–99.1%. When the electric current further increased to 200 mA, however, styrene removal reduced to 92.9–95.5%. When RT was 216 or 108 s and the styrene inlet load was 7.5 or 15 g/(m3·h), varying the styrene inlet concentration did not affect the styrene removal. The influence of styrene inlet concentration on the styrene removal gradually emerged with decrease of RT. At a relative low styrene inlet load (≤30 g/[m3·h]), styrene removal load increased linearly with increasing styrene inlet load. In addition, we found that the optimum pH value was relatively low (5.2) when the electric current (100 mA) was applied to the biological process.