采用零价铁(Fe^0)激活过硫酸盐(PS)产生SO-4·,氧化降解水中的2,4-二叔丁基苯酚(DTBP).通过改变零价铁初始投加量、PS初始浓度、初始p H值、温度等因素,探索这些因素对DTBP降解效果的影响,并且比较了紫外光(UV)、Fe^0以及Fe^2+对DTBP的催化降解效果.结果表明:DTBP的降解速率随着Fe^0投加量由0.5 mmol/L提高到4.0 mmol/L而加快,当投加量提高到5.0 mmol/L时则会发生抑制作用;当DTBP溶液中PS的浓度由0.125 mmol/L提高至0.500 mmol/L时能够加快DTBP的降解速率,但是进一步增大PS的浓度会使DTBP的降解速率先降后升;Fe^0催化降解DTBP的速率随着溶液初始p H值的升高而逐渐减小;热激活PS体系中,提高温度对激活PS降解DTBP的效果有限,当温度升高至55℃时,60 min内仅有42%的DTBP被降解;当温度从35℃升高到45℃时,在热激活PS和Fe^0/PS体系中,DTBP的降解速率均发生轻微的下降;相较UV和Fe^2+,Fe^0能够持续稳定地催化降解DTBP,在60 min内完成98%的最大降解率,且从经济性和节能方面考虑也占有优势.
Zero valent iron (Fe^0) was used to activate persulfate (PS) to generate SO4^- ·and thus to oxidize the 2,4-di-tert-butyl-phenol (DTBP) in water. Then, the degradation of DTBP at various initial Fe^0 dosage, initial PS concentration, initial pH value and temperature was investigated, and the effects of ultra violet light (UV) , Fe^0 and Fe^2+ on the degradation were analyzed in a comparative way. The results indicate that (1) the degradation of DTBP accelerates when the Fe^0 dosage increases from 0. 5 to 4. 0 mmol/L, while an inhibition may occur when the dosage reaches 5.0 mmol/L; (2) the increase in PS concentration from 0. 125 to 0. 500 mmol/L in DTBP solution can accelerate the degradation of DTBP, but the degradation velocity firstly decreases and then increases when the PS concentration continuously increases; (3) the velocity of Fe^0-catalyzed degradation for DTBP gradually decreases with the increase of the initial pH value; (4) temperature has no obvious effect on the activation of PS in degrading the DTBP in a heat-activated PS system, and only 42% of DTBP is degraded within 60 rain at 55 ℃; (5) when the temperature increases from 35 to 45 ℃ , the degradation velocity of DTBP decreases slightly in both the heat- activated PS and the Fe^0/PS systems; and (6) as compared with UV and Fe^2+ , Fe^0 performs a consistent catalytic degradation effect on DTBP, and helps to achieve the highest degradation efficiency of 98% within 60 min, also, the Fe^0-activated degradation is more economical and environmentally friendly.