研究报告
王诗生,赵大唯,章慧娟,盛广宏,刘玲,刘轶鋆,熊仁颖.磁性氮掺杂碳材料活化过硫酸盐降解酸性橙7[J].环境科学学报,2022,42(5):237-246
磁性氮掺杂碳材料活化过硫酸盐降解酸性橙7
- Magnetic N-doped carbonaceous materials activated persulfate for degradation of Acid Orange 7
- 基金项目:国家自然科学基金(No.21808003);安徽省高校自然科学研究项目(No.KJ2018A0056);安徽工业大学校级青年基金(No.RD19100267);2020年安徽省级大创项目(No.S202010360324)
- 王诗生
- 安徽工业大学能源与环境学院,马鞍山 243002;安徽工业大学生物膜法水质净化及利用技术教育部工程研究中心,马鞍山 243002
- 赵大唯
- 安徽工业大学能源与环境学院,马鞍山 243002
- 章慧娟
- 安徽工业大学能源与环境学院,马鞍山 243002;安徽工业大学生物膜法水质净化及利用技术教育部工程研究中心,马鞍山 243002
- 盛广宏
- 安徽工业大学能源与环境学院,马鞍山 243002;安徽工业大学生物膜法水质净化及利用技术教育部工程研究中心,马鞍山 243002
- 刘玲
- 安徽工业大学能源与环境学院,马鞍山 243002
- 刘轶鋆
- 安徽工业大学能源与环境学院,马鞍山 243002
- 熊仁颖
- 安徽工业大学能源与环境学院,马鞍山 243002
- 摘要:采用一步水热碳化法制备出微米级磁性氮掺杂碳材料(Magnetic N-doped Carbonaceous Materials, MNC)作为过硫酸盐(Persulfate, PDS)活化剂,以生成的活性氧化物质降解偶氮类染料酸性橙7(Acid Orange 7, AO7).同时,利用扫描电镜(SEM)、比表面积与孔径测定仪(BET)、振动样品磁强计(VSM)等对MNC进行表征,考察了MNC投加量、PDS浓度、初始pH值和无机阴离子对活化PDS降解AO7的影响,并采用紫外-可见光谱分析、淬灭实验和电子顺磁性共振(Electron Paramagnetic Resonance, EPR)初步探讨了AO7的降解机理.结果表明,MNC呈微米级球状,表面富含含氧基团和氨基等活性点位;饱和磁化强度为12.7 emu·g-1,能在外加磁场条件下实现固液分离.AO7去除率随MNC投加量、PDS浓度的增加而增加,但初始pH对AO7降解的影响呈相反规律,随pH升高而降低.3种无机阴离子对AO7降解抑制程度大小顺序为HCO3->SO42->Cl-.紫外-可见光谱分析表明,AO7分子结构中偶氮键易被氧化断裂,苯环次之,萘环最难断裂降解.淬灭实验和EPR检测结果表明,AO7降解存在自由基路径和非自由基路径,非自由基作用占主要地位,且1O2是AO7降解的占主导作用的活性氧化物种.
- Abstract:The one-step hydrothermal carbonization method was used to prepare magnetic N-doped carbonaceous materials (MNC) as the persulfate (PDS) activator to generate reactive oxidative species for the degradation of azo dye acid orange 7 (AO7). The prepared carbonaceous materials were characterized by means of SEM, BET, XRD and VSM, and the effects of different factors on the degradation of AO7 were investigated, which mainly include the dosage of MNC, PDS concentration, initial pH value and coexisting inorganic anion. The degradation mechanism of AO7 was preliminarily revealed by using UV-visible spectra analysis, quenching experiment and EPR. Results shown that the MNC is spherical in micron scale, and the surface is rich in active sites such as oxygen-containing groups and amino groups; the saturation magnetization is 12.7 emu·g-1, which indicates that the solid-liquid separation can be achieved under the external magnetic field. The degradation rate of AO7 increases with the increment of MNC dosage and PDS concentration; but the initial pH value affects the removal of AO7 in the opposite way. The inhibition degree order of the three inorganic anions on the AO7 degradation is HCO3->SO42->Cl-.Results of UV-visible spectra analysis shown that the azo bond in the AO7 structure can be easily broken by oxidation, followed by the benzene ring, and the naphthalene ring is the most difficult to be degraded. Results of quenching experiment and EPR shown that radical and non-radical oxidation pathway could simultaneous act on the AO7 degradation, during which the non-radical oxidation plays the key role, and the non-singlet oxygen (1O2) is the dominant active oxidation species for AO7 degradation.