[Composite CVOCs Removal in a Combined System of Nonthermal Plasma and a Biotrickling Filter]

A coupling system of nonthermal plasma and a biotrickling filter was used to remove a gas mixture of chlorobenzene (CB) and dichloromethane (DCE). The effects of inlet gas concentration and gas flow rate on the removal of the target pollutants in the coupling system were investigated at the frequency of 10000 Hz and specific input energy (SIE) of 6111 J·L^-1. Furthermore, the advantages of the plasma-bio-coupled system were revealed by analyzing the relationship between the degradation products and SIE, biomass, or biodiversity in the biotrickling filter. The results showed that when the SIE and gas flow rate were constant, increasing the initial concentration would decrease the removal efficiency of the mixed gas. The optimal appropriate gas flow rate was 0.71 L·min^-1 when considering the cost. The CO₂ production amount, CO₂ selectivity, and chloride ion concentration increased with the increase of SIE when both the CB and DCE concentrations were 500 mg·m^-3 and the gas flow rate was 0.71 L·min^-1. The protein content of the biofilter column gradually increased as the reactor operation progressed, and the biomass of the lower layer was higher than that of the upper layer. The high-throughput sequencing analysis showed that the biological community in the biotrickling filter keeped rich and diversified.