秸秆活性炭活化过一硫酸盐降解酸性橙7

将磷酸氢二铵((NH_4)_2HPO_4)作为活化剂制备秸秆活性炭(SAC),并用其活化过一硫酸盐(PMS)产生硫酸根自由基(SO_4~-·)降解偶氮染料酸性橙7(AO7).首先对活化前后的SAC进行FTIR表征,发现(NH_4)_2HPO_4活化后的SAC含氧官能团特征峰强度增强,可能有利于过一硫酸钾的活化.其次研究了活化剂浓度、SAC投加量、PMS浓度、初始pH、抑制剂对AO7降解效果的影响.结果表明,AO7脱色率随着活化剂浓度、SAC投加量、PMS浓度的增加而增加;同时在偏中性条件下,有利于SAC活化PMS脱色AO7;加入相同物质的量比(2000/1)的甲醇、叔丁醇、苯酚,55 min内AO7脱色率分别为88.4%、66.2%、13.4%,苯酚对反应抑制效果最好,表明SAC表面的硫酸根和羟基自由基在AO7脱色中起主要作用.最后通过紫外光谱扫描、气质联用(GC-MS)和TOC分析表明,AO7的偶氮键和萘环结构被破坏,生成含苯环类中间产物,最终矿化为二氧化碳和水,矿化率可达31.7%.

Degradation of acid orange 7 by peroxymonosulfate activated by straw activated carbon

Straw activated carbon (SAC) was prepared from straw with diammonium phosphate((NH₄)₂HPO₄)as activator.SAC was then used to activate peroxymonosulfate (PMS) to produce sulfate radical for the decolorization of azo dye Acid Orange 7. The characterization of the synthesized SAC by FTIR indicated that the peak intensity of oxygen containing functional group of SAC increased, potentially favorable for PMS activation. The effect of (NH₄)₂HPO₄ concentration, SAC dosage, PMS concentrations, initial pH and radical scavengerson the degradation of AO7 were studied. The results demonstrated that the decolorization of AO7 increased with increasing of (NH₄)₂HPO₄ concentration, SAC dosage, PMS concentration. Neutral pH was most favorable for SAC to activate PMS for AO7 decolorization. After addition of excess amount (2000/1) of methanol, tert-butanol and phenol, the decolorization efficiencies of AO7 were 88.4%, 66.2%, 13.4%, respectively,and thus the surface bound sulfate and hydroxyl radicals were responsible for AO7 decolorization. From the analysis of GC/MS,UV-Vis spectra, and TOC, the azo band and naphthalene ring of AO7 were destroyed by radicals, generating the benzene-containing intermediate products, and mineralizing to CO₂ and H₂O (31.7%).