掺氮生物炭活化过硫酸盐降解双酚A的研究

The Research of Bisphenol A Degradation by Persulfate Activated with N-doped Biochar

该文以悬铃木为生物质原料制备生物炭,以尿素为前驱体,采用不同的热解温度(400、500、600、700、800、900℃)制备含有不同活性组分比例的氮掺杂生物炭(NCX)。NCX作为催化剂被首次用来深入研究过一硫酸盐(PMS)和过二硫酸盐(PDS)降解水中双酚A(BPA)的不同活化机制。在PMS+NCX体系中,较低制备温度的NC500便能够表现出对BPA去除的优异催化性能,而在PDS+NCX体系中,随着温度的升高,NCX催化剂的催化性能逐渐提高。化学淬灭试验、电子顺磁共振以及NBT测试证明在PMS+NC500体系中1O2和O_(2)^(•-)是主要的活性氧物种(ROS),而在PDS+NC900体系中,O_(2)^(•-)是主要的活性氧物种。通过一系列的电化学测试,作者发现在两体系中降解BPA的过程中均存在非自由基途径(电子转移)。

In this study,sycamore was used as biomass and urea was used as precursor to prepare N-doped biochar(NCX,X represented temperature)containing different active components at designed pyrolysis temperatures(400,500,600,700,800,900℃).The different activation mechanisms of PMS and PDS were discussed in depth for the first time through N-doped biochar at different pyrolysis temperatures.In the PMS+NCX system,NC500 at lower preparation tem⁃perature showed excellent catalytic performance for bisphenol A(BPA)removal,while in the PDS+NCX system,the cata⁃lytic performance of NCX catalyst increased gradually with the increasing of temperature.The chemical quenching experi⁃ment,electron paramagnetic resonance(EPR)and nitrotetrazolium blue chloride(NBT)test were conducted to clarify the crucial reactive oxidative species(ROS).The 1O2 and O_(2)^(•-)dominated radical degradation pathway in the PMS+NC500 sys⁃tem and O_(2)^(•-)was the main ROS species reigned radical degradation pathway in the PDS+NC900 system were revealed.Electrochemical tests included chronoamperometry,linear sweep voltammograms(LSV)and electrochemical impedance spectroscopy(EIS)demonstrated the existence of non-free radical pathways(electron transfer)in the degradation of BPA in both systems.