低温等离子体-生物耦合系统对复合CVOCs的降解

采用低温等离子体-生物耦合系统降解氯苯和二氯乙烷混合气体,考察频率为10 000 Hz,能量密度(specific input energy,SIE)为6 111 J·L-1时进气浓度和气体流速对目标污染物降解的影响,并通过对产物与SIE之间关系以及生物滴滤塔中生物量和生物多样性的分析,更进一步揭示等离子-生物耦合系统的优势.结果表明,当SIE和气体流速一定时,增加初始浓度会降低混合气体的去除率;从经济效益考虑,气体流速宜采用0.71 L·min~(-1).经产物分析发现,在二氯乙烷和氯苯的浓度均为500 mg·m-3,气体流速为0.71 L·min~(-1)的条件下,二氧化碳的生成量以及选择性均随着SIE的增大而增大;在同样的条件下氯离子浓度随着SIE的增加而逐渐变大;生物滴滤塔中蛋白质含量随着反应器运行逐渐增加最后趋于稳定,下层的生物量高于上层;通过高通量测序分析,结果显示生物滴滤塔中的生物保有丰富的群落及物种多样性的特点.

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.