DBD反应器关键操作参数对2,4-二氯酚去除的影响

采用同轴喷雾式介质阻挡放电(DBD)反应器处理2,4-二氯酚(2,4-DCP)模拟废水,考察了水质、废水流量、载气流量、放电频率等关键操作参数对2,4-DCP去除的影响。自来水中的CO₃^2-/HCO₃^-能够中和生成的硝酸/亚硝酸(载气含N₂),同时也能清除放电过程中产生的自由基,因而不利于2,4-DCP的去除。在DBD反应器的操作参数中,载气流量对于活性组分的产生及气相到液相的传质有显著影响,是最为关键的操作参数。反应器操作参数的变化会影响放电过程。同轴式反应器和废水雾化对污染物的矿化有利。在废水流量50 mL/min、载气流量15 L/min、放电频率17 kHz的最佳条件下处理60 min,2,4-DCP和TOC的去除率分别为69.77%和31.85%。

Effects of key operation parameters on removal of 2,4-dichlorophenol in a DBD reactor

A coaxial spray dielectric barrier discharge (DBD) reactor was used to treat the simulated 2,4-dichlorophenol wastewater. The effects of key operation parameters such as water quality,wastewater flow,carrier gas flow and discharge frequency on removal of 2,4-dichlorophenol (2,4-DCP) were investigated. CO₃^2-/HCO₃^- in tap water could neutralize the generated nitric acid/nitrous acid (the carrier gas contains N₂),but would scavenge free radicals generated during the discharge process,which was not beneficial to the removal of 2,4-DCP. Since carrier gas flow had a significant impact on active species generation and gas-liquid mass transfer,it was the most critical operation parameter of DBD reactor. The change of reactor operation parameters affected the discharge process. The coaxial reactor and wastewater atomization were beneficial to the mineralization of pollutant. When the wastewater was treated under the optimal conditions of wastewater flow 50 mL/min,carrier gas flow 15 L/min and discharge frequency 17 kHz for 60 min,the removal rate of 2,4-DCP and TOC were 69.77% and 31.85%,respectively.