陈殿君

摘要：采用双介质阻挡放电（DBD）研究针铁矿煅烧温度、负载量、输入能量、停留时间、初始浓度及湿度对等离子体催化降解苯的影响，分析降解产物及碳氧化物选择性，并对降解机理进行探究。研究表明，在该等离子体发生装置下，最佳条件为煅烧温度350 ℃、负载量4.0%、停留时间1.408 s、相对湿度70%左右。在输入能量为1 242 J/L、初始浓度为400 mg/m3时，相对单独DBD，针铁矿的加入将苯的降解率从62.00%提升至73.36%，臭氧浓度从132.8 mg/m3降至36.8 mg/m3，碳氧化物选择性从67.13%提升至82.14%，出口NO2浓度从7.95 mg/m3降低至1.70 mg/m3。利用FT-IR、GC-MS分析降解产物，发现最终产物主要为CO2、CO、O3、微量NO2及少量硝基苯酚、苯醌等。

关键词：介质阻挡放电（DBD）；等离子体；降解；苯；针铁矿

中图分类号：X701；X511 文献标识码：A 文章编号：0439-8114（2017）17-3250-06

DOI：10.14088/j.cnki.issn0439-8114.2017.17.015

Decomposing Benzene Using Dielectric Barrier Discharge with Goethite

CHEN Dian-jun

（College of Resources and Environmental Engineering，Hefei University of Technology，Hefei 230009，China）

Abstract： The effects of calcination temperature，loading，input energy，residence time，initial concentration and humidity on the degradation of benzene by plasma were investigated using coaxial dielectric barrier discharge. The degradation products and the selectivity of carbon oxides were analyzed. And the mechanism of degradation was explored. The results showed that the optimal conditions were calcination temperature 350 ℃，loading capacity 4%，residence time 1.408 s，relative humidity 70%，under the condition of the plasma generator. When the input energy was 1 242 J/L and the initial concentration was 400 mg/m3， the addition of goethite increased the degradation rate of benzene from 62.00% to 73.36%，and the ozone concentration decreased from 132.8 mg/m3 to 36.8 mg/m3， the selectivity of carbon oxides increased from 67.13% to 82.14%，and the export NO2 concentration decreased from 7.95 mg/m3 to 1.70 mg/m3. The products were analyzed by FT-IR and GC-MS. The final products were CO2，CO，O3，a small amount of nitrophenol and benzoquinone， etc.

Key words： dielectric barrier discharge（DBD）； plasma； degradation； benzene； goethite

苯作為一种高毒VOC，有神经毒性、致癌作用，可致白血病和职业性苯中毒[1，2]。目前VOCs的去除方法主要有燃烧法[3]、吸附法[4]、生物法[5]、低温等离子体法[6]、光催化法[7，8]等。其中低温等离体子由于其设备简单、能耗低、处理彻底、副产物少、适应性强等优点而备受关注[9]。姜理英等[10]利用介质阻挡放电（DBD）降解氯苯，结果表明DBD能有效去除氯苯，降解率与湿度有关，臭氧浓度随电压的升高而增多。Tang等[11]用DBD产生低温等离子体降解甲苯，比较含Ag的3种双组份催化剂与单独等离子体对甲苯的降解效果，结果表明，在输入能量密度为60 J/L时，AgMnOx的加入将甲苯的降解率由62%提升至100%。李云霞等[12]在等离子体余辉区置入隐钾锰矿，结果表明，甲苯去除率得以提高，O3浓度也明显降低。Dang等[13]研究了在循环气体条件下等离子体降解甲苯，结果表明，MnOx/γ-Al2O3和AgOx/γ-Al2O3的加入能提高COx的选择性，也发现空气条件下会产生NOx。……