Fe-AC微电解活化过硫酸盐降解直接耐酸大红4BS

Decolorization of direct fast scarlet 4BS by persulfate activated using iron-carbon micro-electrolysis

为快速脱色降解偶氮类染料,同时解决零价铁活化效率低、易被氧化的问题,以直接耐酸大红4BS(大红4BS)为模拟废水污染物,通过Fe-AC/PDS(铁碳微电解活化过硫酸钠)反应体系对大红4BS进行脱色降解。对影响大红4BS降解的几种因素如Fe:AC(铁碳质量比)、PDS浓度、初始pH等进行探究。结果表明,大红4BS脱色率在Fe:AC=3:1时高达94.7%。增大PDS浓度能明显促进反应进行,但超过5 mmol·L^(-1)时,对体系影响不大。初始溶液pH对Fe-AC/PDS体系降解大红4BS作用显著,在酸性和中性(pH=3.02、4.67、7.32)时,大红4BS的脱色率分别高达98.8%、96.2%、94.7%,但在碱性(pH=9.38、10.78)条件下,其脱色率只有24.5%、18.7%。无机盐阴离子对Fe-AC/PDS体系降解大红4BS有抑制作用,而阳离子对其产生促进作用。自由基俘获实验表明Fe-AC/PDS体系降解大红4BS并不仅仅只是自由基的氧化反应,还存在其他复杂反应,继而对Fe-AC/PDS体系降解大红4BS的机理进行探讨。

Advanced oxidation technology based on sulfate radical may be an effective method for decolorization of azo dyes. In this paper, decolorization and degradation of azo dyes direct scarlet 4BS by persulfate activated using iron-carbon micro-electrolysis was reported. Several factors that affect the degradation of red 4BS was explored, such as Fe ： AC, initial concentration of PDS,initial pH and many more. The results show that decolorization rate of red 4BS reached 94.7% when Fe ： AC=3 ： 1. The 4BS decolorization rate increased with the increasing of PDS concentration, but there was no significant change when PDS more than 5 mmol.L-1. The initial pH have significant effect for red 4BS degradation in Fe-AC/PDS system, the decolorization rate of red 4BS reached 98.8%, 96.2%, 94.7% in acidic and neutral solutions when pH=3.02,4.67,7.32, respectively, the decolorization rate was only 24.5%, 18.7% in alkaline solution when pH=9.38,10.78, respectively. Inorganic anions inhibited the degradation of the 4BS in the Fe-AC/PDS system, while cations promoted the degradation.Free radical capture test showed that degradation of red 4BS in Fe-AC/PDS system is not just free radical oxidation,than discuss the mechanism of Fe-AC/PDS degrade red 4BS.