零价铁与过硫酸盐异相芬顿降解活性艳橙X-GN

采用零价铁(Fe~0)与过硫酸盐构建异相类芬顿体系,由Fe0腐蚀释放Fe~(2+)催化S_2 O_8~(2-)产生硫酸根自由基快速降解偶氮染料活性艳橙,考察了初始p H值、Fe~0投加量、过硫酸盐投加量和温度对降解过程的影响。结果表明,当活性艳橙初始浓度为100 mg/L、pH值为7、Fe~0投加量为0.5 g/L、过硫酸盐投加量为1 mmol/L和反应温度为30℃时,反应60 min后活性艳橙降解率达到92.6%。酸性条件和提高反应温度均有利反应的进行,而且活性艳橙的降解率在初始pH值为9时也高于90%。反应过程符合准一级动力学,表观反应速率常数k为0.0513 min~(-1)(30℃)。UV-Vis扫描显示,活性艳橙的发色基团在反应过程中被破坏。由Fe~0与S_2O_8~(2-)构成的异相Fenton体系可作为一种高效手段用于染料废水的处理。

Effective Degradation of Reactive Brilliant Orange X-GN by Heterogeneous Fenton Reaction with Zero Valent Iron and Persulfate

Heterogeneous Fenton like system was established by zero valent iron (ZVI) and persulfate to degrade an azo dye reactive brilliant orange (X-GN) with sulfate radicals generated in situ from ZVI and persulfate. The effects of initial pH, ZVI and persulfate dosage, and temperature on the degradation process were investigated. The results showed that an X-GN degradation efficiency of 92.6% was achieved after 60 min of reaction time with an initial X-GN concentration of 100 mg/L under typical o conditions ( ZVI of 0.5 g/L, persulfate of 1 mmol/L, pH of 7 and at 30 C). Degradation of X-GN was an acid driven process and a degradation efficiency of more than 90% was obtained as the initial pH was 9. The degradation efficiency of X-GN also increased at higher reaction temperature. The degradation of X-GN followed pseudo-first order kinetics and the apparent reaction rate constant-1 o k was 0.0513 min (at 30 C). UV-Vis spectra showed that N=N was destroyed during the reaction. Therefore, the combination of ZVI and persulfate could be taken as a promising technology for decolorization of dyeing wastewater.