碳纳米管活化过一硫酸盐降解金橙G过程及动力学

采用碳纳米管(CNT)作为固体活化剂,活化过一硫酸盐(PMS)氧化降解偶氮染料金橙G(OG).结果表明,CNT活化PMS降解OG的效果要比活性炭(GAC)好,45 min可使OG的脱色率达到99%;并研究了CNT活化PMS降解OG的机制及反应过程的动力学,发现CNT活化PMS产生的自由基主要是SO_4~-·,活化场所在CNT的表面.通过对CNT/PMS体系降解OG的主要影响因素(温度、OG初始浓度、CNT投加量、PMS浓度、初始pH)进行一级动力学拟合.最后通过紫外可见光谱分析,发现OG在479 nm和330 nm处吸收峰强度明显减少,表明OG分子中偶氮键及萘环结构均一定程度被破坏;且CNT/PMS降解体系对染料OG具有一定矿化率.

Kinetics for Degradation of Orange G with Peroxymonosulfate Activated by Carbon Nanotubes

Carbon nanotube (CNT) was used as an activator to activate peroxymonosulfate (PMS) to degrade azo dye orange G (OG) in aqueous solution. The results indicated that CNT exhibited a much better performance in activating PMS to decolorize OG than activated carbon (GAC), with 99% decolorization of OG achieved within 45 min. Afterwards, the degradation mechanism of OG in CNT activated PMS system was explored, and SO₄^-·was found to be dominantly responsible for OG degradation, which mainly took place on the surface of CNT. Effects of various factors, including temperatures, initial concentration of OG, CNT loadings, PMS dosage, and initial pH, on degradation of OG were then investigated, and OG degradation in these cases well conformed to first-order kinetics. From the analysis of UV-vis spectra of OG during the reaction, the peaks at 479 nm and 330 nm were found to be significantly decreased, suggesting that the azo band and naphthaline ring were destructed, respectively. Finally, TOC analysis indicated that a certain degree of OG mineralization was obtained in CNT activated PMS system.