丙酮活化过一硫酸盐性能及非自由基机制

利用丙酮活化过一硫酸盐(Peroxymonosulfate,PMS)氧化降解酸性橙7(AO7),考察了丙酮投加量、PMS浓度、初始pH值及共存阴离子等反应条件对AO7氧化降解的影响,探讨了丙酮/PMS反应体系中的反应机制.结果表明,当初始p H为9.0、n(PMS)/n(AO7)为17.5∶1、丙酮投加量为10 mmol·L-1时,反应30 min可使AO7的降解率达到99.8%.在丙酮/PMS的活化体系中,随着丙酮投加量、PMS浓度和p H的升高,AO7的降解率也逐渐增大,碱性条件下最有利于AO7的降解.自由基淬灭实验分析表明,单线态氧(1O2)是氧化降解AO7的主要活性物种.Cl-、CO2-3对丙酮/PMS体系中AO7的降解有促进作用,离子浓度越高,AO7降解速率越快,腐殖酸(HA)的加入对AO7的降解有轻微的抑制作用.紫外可见光谱分析表明,AO7分子中的偶氮键及萘环结构被破坏,从而得到降解.

Performance and non-radical mechanism of activation of peroxymonosulfate by acetone

The degradation of acid orange 7 (AO7) with peroxymonosulfate (PMS) activated by acetone was investigated. The effects of reaction conditions including acetone dosage, PMS dosage, initial solution pH and coexisting anions on the oxidative degradation of AO7 were evaluated and the reaction mechanism in acetone/PMS reaction system was investigated. The results indicated that the removal of AO7 could reach 99% when the initial solution pH was 9, n(PMS)/n(AO7) was 17.5:1 and the acetone dosage was 10 mmol·L^-1. In acetone/PMS activation system, with the increase of acetone dosage, PMS concentration and pH, the degradation of AO7 also increased gradually. Alkaline pH was most favorable for the degradation of AO7. The results of free radical quenching experiments showed that singlet oxygen (¹O₂) was the main active species for the degradation of AO7. Cl^- and CO₃^2- ions promoted the degradation of AO7 in acetone/PMS system, and the degradation of AO7 increased with increasing concentration of anions. The addition of humic acid (HA) had little inhibition on the degradation of AO7. From the analysis of UV-vis spectra, the azo bond and naphthalene ring structure in AO7 molecules were found to be destroyed.